diff --git a/.github/workflows/build-board-custom.yml b/.github/workflows/build-board-custom.yml
index b91ccbd2d28f3..39976cd7c1ecc 100644
--- a/.github/workflows/build-board-custom.yml
+++ b/.github/workflows/build-board-custom.yml
@@ -42,21 +42,29 @@ jobs:
       run: |
         git clone --filter=tree:0 https://github.com/adafruit/circuitpython.git $GITHUB_WORKSPACE
     - name: Checkout head / tag
+      env:
+        TAG: ${{ inputs.version == 'latest' && 'HEAD' || inputs.version }}
       run: |
-        git checkout ${{ inputs.version == 'latest' && 'HEAD' || inputs.version }}
+        git checkout "$TAG"
     - name: fork compatibility
       if: github.repository_owner != 'adafruit'
+      env:
+        REPO: ${{ github.repository }}
       run: |
-        git remote add fork https://github.com/${{github.repository}}.git
+        git remote add fork "https://github.com/$REPO.git"
         git fetch fork --filter=tree:0
     - name: branch compatibility
       if: inputs.branch != 'main' && inputs.version == 'latest' && github.repository_owner == 'adafruit'
+      env:
+        BRANCH: ${{ inputs.branch }}
       run: |
-        git checkout ${{inputs.branch}}
+        git checkout "$BRANCH"
     - name: branch compatibility (fork)
       if: inputs.branch != '' && inputs.version == 'latest' && github.repository_owner != 'adafruit'
+      env:
+        BRANCH: ${{ inputs.branch }}
       run: |
-        git checkout -b fork-branch fork/${{inputs.branch}}
+        git checkout -b fork-branch "fork/$BRANCH"
     - name: Set up identifier
       if: inputs.debug || inputs.flags != ''
       run: |
@@ -101,7 +109,12 @@ jobs:
         riscv64-unknown-elf-gcc --version || true
         mkfs.fat --version || true
     - name: Build board
-      run: make -j4 ${{ inputs.flags }} BOARD=${{ inputs.board }} DEBUG=${{ inputs.debug && '1' || '0' }} TRANSLATION=${{ inputs.language }}
+      env:
+        TRANSLATION: ${{ inputs.language }}
+        BOARD: ${{ inputs.board }}
+        FLAGS: ${{ inputs.flags }}
+        DEBUG: ${{ inputs.debug && '1' || '0' }}
+      run: make -j4 $FLAGS BOARD="$BOARD" DEBUG=$DEBUG TRANSLATION="$TRANSLATION"
       working-directory: ports/${{ steps.set-up-port.outputs.port }}
     - name: Upload artifact
       uses: actions/upload-artifact@v4
diff --git a/.github/workflows/build-boards.yml b/.github/workflows/build-boards.yml
index be076e0789f86..7daa7ae7e322e 100644
--- a/.github/workflows/build-boards.yml
+++ b/.github/workflows/build-boards.yml
@@ -31,6 +31,7 @@ jobs:
         submodules: false
         show-progress: false
         fetch-depth: 1
+        persist-credentials: false
 
     - name: Set up python
       uses: actions/setup-python@v5
diff --git a/.github/workflows/build-mpy-cross.yml b/.github/workflows/build-mpy-cross.yml
index 9d94fb638ef5a..831ad3082275b 100644
--- a/.github/workflows/build-mpy-cross.yml
+++ b/.github/workflows/build-mpy-cross.yml
@@ -33,6 +33,7 @@ jobs:
         submodules: false
         show-progress: false
         fetch-depth: 1
+        persist-credentials: false
     - name: Set up python
       uses: actions/setup-python@v5
       with:
@@ -57,9 +58,12 @@ jobs:
       run: make -C mpy-cross -j4 -f Makefile.${{ matrix.mpy-cross }}
 
     - name: Set output
+      env:
+        EX: ${{ env[format('EX_{0}', matrix.mpy-cross)] || matrix.mpy-cross }}
+        OS: ${{ env[format('OS_{0}', matrix.mpy-cross)] }}"
       run: |
-        echo >> $GITHUB_ENV "EX=${{ env[format('EX_{0}', matrix.mpy-cross)] || matrix.mpy-cross }}"
-        echo >> $GITHUB_ENV "OS=${{ env[format('OS_{0}', matrix.mpy-cross)] }}"
+        echo >> $GITHUB_ENV "EX=$EX"
+        echo >> $GITHUB_ENV "OS=$OS"
 
     - name: Upload artifact
       uses: actions/upload-artifact@v4
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0f8b1b7638170..7d37baebdc15d 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -33,6 +33,7 @@ jobs:
         submodules: false
         show-progress: false
         fetch-depth: 1
+        persist-credentials: false
     - name: Set up python
       uses: actions/setup-python@v5
       with:
@@ -66,7 +67,9 @@ jobs:
         EXCLUDE_COMMIT: ${{ github.event.pull_request.head.sha }}
     - name: Set head sha (pull)
       if: github.event_name == 'pull_request'
-      run: echo "HEAD_SHA=${{ github.event.pull_request.head.sha }}" >> $GITHUB_ENV
+      env:
+        HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+      run: echo "HEAD_SHA=$HEAD_SHA" >> $GITHUB_ENV
     - name: Set base sha (pull)
       if: github.event_name == 'pull_request'
       run: git cat-file -e $SHA && echo "BASE_SHA=$SHA" >> $GITHUB_ENV || true
@@ -74,7 +77,9 @@ jobs:
         SHA: ${{ steps.get-last-commit-with-checks.outputs.commit_sha || github.event.pull_request.base.sha }}
     - name: Set head sha (push)
       if: github.event_name == 'push'
-      run: echo "HEAD_SHA=${{ github.event.after }}" >> $GITHUB_ENV
+      env:
+        SHA: ${{ github.event.after }}
+      run: echo "HEAD_SHA=$SHA" >> $GITHUB_ENV
     - name: Set base sha (push)
       if: github.event_name == 'push'
       run: git cat-file -e $SHA && echo "BASE_SHA=$SHA" >> $GITHUB_ENV || true
@@ -114,6 +119,7 @@ jobs:
         submodules: false
         show-progress: false
         fetch-depth: 1
+        persist-credentials: false
     - name: Set up python
       uses: actions/setup-python@v5
       with:
@@ -149,9 +155,9 @@ jobs:
           (github.event_name == 'push' && github.ref == 'refs/heads/main' && github.repository_owner == 'adafruit') ||
           (github.event_name == 'release' && (github.event.action == 'published' || github.event.action == 'rerequested'))
       run: |
-        [ -z "$AWS_ACCESS_KEY_ID" ] || aws s3 cp mpy-cross-macos-universal s3://adafruit-circuit-python/bin/mpy-cross/macos/mpy-cross-macos-${{ env.CP_VERSION }}-universal --no-progress --region us-east-1
-        [ -z "$AWS_ACCESS_KEY_ID" ] || aws s3 cp mpy-cross/build-arm64/mpy-cross-arm64 s3://adafruit-circuit-python/bin/mpy-cross/macos/mpy-cross-macos-${{ env.CP_VERSION }}-arm64 --no-progress --region us-east-1
-        [ -z "$AWS_ACCESS_KEY_ID" ] || aws s3 cp mpy-cross/build/mpy-cross s3://adafruit-circuit-python/bin/mpy-cross/macos/mpy-cross-macos-${{ env.CP_VERSION }}-x64 --no-progress --region us-east-1
+        [ -z "$AWS_ACCESS_KEY_ID" ] || aws s3 cp mpy-cross-macos-universal s3://adafruit-circuit-python/bin/mpy-cross/macos/mpy-cross-macos-"${CP_VERSION}"-universal --no-progress --region us-east-1
+        [ -z "$AWS_ACCESS_KEY_ID" ] || aws s3 cp mpy-cross/build-arm64/mpy-cross-arm64 s3://adafruit-circuit-python/bin/mpy-cross/macos/mpy-cross-macos-"${CP_VERSION}"-arm64 --no-progress --region us-east-1
+        [ -z "$AWS_ACCESS_KEY_ID" ] || aws s3 cp mpy-cross/build/mpy-cross s3://adafruit-circuit-python/bin/mpy-cross/macos/mpy-cross-macos-"${CP_VERSION}"-x64 --no-progress --region us-east-1
       env:
         AWS_PAGER: ''
         AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
@@ -170,6 +176,7 @@ jobs:
         submodules: false
         show-progress: false
         fetch-depth: 1
+        persist-credentials: false
     - name: Set up python
       uses: actions/setup-python@v5
       with:
@@ -188,7 +195,7 @@ jobs:
         name: stubs
         path: circuitpython-stubs/dist/*
     - name: Test Documentation Build (HTML)
-      run: sphinx-build -E -W -b html -D version=${{ env.CP_VERSION }} -D release=${{ env.CP_VERSION }} . _build/html
+      run: sphinx-build -E -W -b html -D version="$CP_VERSION" -D release="$CP_VERSION" . _build/html
     - uses: actions/upload-artifact@v4
       with:
         name: docs-html
@@ -271,6 +278,7 @@ jobs:
         submodules: false
         show-progress: false
         fetch-depth: 1
+        persist-credentials: false
     - name: Set up submodules
       uses: ./.github/actions/deps/submodules
     - name: build mpy-cross
diff --git a/.github/workflows/create-website-pr.yml b/.github/workflows/create-website-pr.yml
index 8f4cce7691c1b..32c1792fa6c74 100644
--- a/.github/workflows/create-website-pr.yml
+++ b/.github/workflows/create-website-pr.yml
@@ -22,6 +22,7 @@ jobs:
         submodules: false
         show-progress: false
         fetch-depth: 1
+        persist-credentials: false
     - name: Set up python
       uses: actions/setup-python@v5
       with:
diff --git a/.github/workflows/pre-commit.yml b/.github/workflows/pre-commit.yml
index b3517d748f5e7..778270dc08c8f 100644
--- a/.github/workflows/pre-commit.yml
+++ b/.github/workflows/pre-commit.yml
@@ -22,6 +22,7 @@ jobs:
         submodules: false
         show-progress: false
         fetch-depth: 1
+        persist-credentials: false
     - name: Set up python
       uses: actions/setup-python@v5
       with:
diff --git a/lib/mbedtls_config/mbedtls_port.c b/lib/mbedtls_config/mbedtls_port.c
index 73929c85e81ed..b7e8ceae5de0f 100644
--- a/lib/mbedtls_config/mbedtls_port.c
+++ b/lib/mbedtls_config/mbedtls_port.c
@@ -27,15 +27,13 @@
 
 #if CIRCUITPY_SSL_MBEDTLS
 
+#include "py/runtime.h"
 #include "mbedtls_config.h"
 #include "mbedtls/entropy_poll.h"
 
-#include "hardware/rtc.h"
 #include "shared/timeutils/timeutils.h"
 #include "shared-bindings/os/__init__.h"
-
-#include "hardware/rtc.h"
-#include "shared/timeutils/timeutils.h"
+#include "shared-bindings/time/__init__.h"
 
 extern uint8_t rosc_random_u8(size_t cycles);
 
@@ -46,9 +44,10 @@ int mbedtls_hardware_poll(void *data, unsigned char *output, size_t len, size_t
 }
 
 time_t rp2_rtctime_seconds(time_t *timer) {
-    datetime_t t;
-    rtc_get_datetime(&t);
-    return timeutils_seconds_since_epoch(t.year, t.month, t.day, t.hour, t.min, t.sec);
+    mp_obj_t datetime = mp_load_attr(MP_STATE_VM(rtc_time_source), MP_QSTR_datetime);
+    timeutils_struct_time_t tm;
+    struct_time_to_tm(datetime, &tm);
+    return timeutils_seconds_since_epoch(tm.tm_year, tm.tm_mon, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec);
 }
 
 #endif
diff --git a/locale/ID.po b/locale/ID.po
index 4bc03c8ccd76d..973aa69ffb742 100644
--- a/locale/ID.po
+++ b/locale/ID.po
@@ -6,15 +6,15 @@ msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
 "POT-Creation-Date: 2021-01-04 12:55-0600\n"
-"PO-Revision-Date: 2023-11-16 15:03+0000\n"
-"Last-Translator: Scott Shawcroft <scott@tannewt.org>\n"
+"PO-Revision-Date: 2024-11-06 14:00+0000\n"
+"Last-Translator: Iqbal Rifai <yukifag@pm.me>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
 "Language: ID\n"
 "MIME-Version: 1.0\n"
 "Content-Type: text/plain; charset=UTF-8\n"
 "Content-Transfer-Encoding: 8bit\n"
 "Plural-Forms: nplurals=1; plural=0;\n"
-"X-Generator: Weblate 5.2\n"
+"X-Generator: Weblate 5.8.2\n"
 
 #: main.c
 msgid ""
@@ -1714,15 +1714,15 @@ msgstr "Jumlah pin terlalu besar"
 #: ports/stm/common-hal/alarm/pin/PinAlarm.c
 #: ports/stm/common-hal/pulseio/PulseIn.c
 msgid "Pin interrupt already in use"
-msgstr ""
+msgstr "Pin interupsi sudah digunakan"
 
 #: shared-bindings/adafruit_bus_device/spi_device/SPIDevice.c
 msgid "Pin is input only"
-msgstr ""
+msgstr "Pin hanya input"
 
 #: ports/raspberrypi/common-hal/countio/Counter.c
 msgid "Pin must be on PWM Channel B"
-msgstr ""
+msgstr "Pin harus berada di Saluran PWM B"
 
 #: shared-bindings/rgbmatrix/RGBMatrix.c
 #, c-format
@@ -1741,11 +1741,11 @@ msgstr "Pin harus berurutan"
 
 #: ports/raspberrypi/common-hal/rotaryio/IncrementalEncoder.c
 msgid "Pins must be sequential GPIO pins"
-msgstr ""
+msgstr "Pin harus merupakan pin GPIO yang berurutan"
 
 #: ports/raspberrypi/common-hal/audiopwmio/PWMAudioOut.c
 msgid "Pins must share PWM slice"
-msgstr ""
+msgstr "Pin harus berbagi potongan PWM"
 
 #: shared-module/usb/core/Device.c
 msgid "Pipe error"
@@ -1757,11 +1757,11 @@ msgstr "Tambahkan module apapun pada filesystem\n"
 
 #: shared-module/vectorio/Polygon.c
 msgid "Polygon needs at least 3 points"
-msgstr ""
+msgstr "Poligon membutuhkan setidaknya 3 poin"
 
 #: supervisor/shared/safe_mode.c
 msgid "Power dipped. Make sure you are providing enough power."
-msgstr ""
+msgstr "Daya menurun. Pastikan Anda menyediakan daya yang cukup."
 
 #: shared-bindings/_bleio/Adapter.c
 msgid "Prefix buffer must be on the heap"
@@ -1779,19 +1779,19 @@ msgstr ""
 
 #: ports/raspberrypi/common-hal/rp2pio/StateMachine.c
 msgid "Program does IN without loading ISR"
-msgstr ""
+msgstr "Program melakukan IN tanpa memuat ISR"
 
 #: ports/raspberrypi/common-hal/rp2pio/StateMachine.c
 msgid "Program does OUT without loading OSR"
-msgstr ""
+msgstr "Program melakukan OUT tanpa memuat OSR"
 
 #: ports/raspberrypi/bindings/rp2pio/StateMachine.c
 msgid "Program size invalid"
-msgstr ""
+msgstr "Ukuran program tidak valid"
 
 #: ports/espressif/common-hal/espulp/ULP.c
 msgid "Program too long"
-msgstr ""
+msgstr "Program terlalu lama"
 
 #: shared-bindings/digitalio/DigitalInOut.c
 msgid "Pull not used when direction is output."
@@ -1799,11 +1799,11 @@ msgstr "Pull tidak digunakan saat arah output."
 
 #: ports/raspberrypi/common-hal/countio/Counter.c
 msgid "RISE_AND_FALL not available on this chip"
-msgstr ""
+msgstr "RISE_AND_FALL tidak tersedia pada chip ini"
 
 #: shared-module/displayio/OnDiskBitmap.c
 msgid "RLE-compressed BMP not supported"
-msgstr ""
+msgstr "BMP-terkompresi RLE tidak didukung"
 
 #: ports/stm/common-hal/os/__init__.c
 msgid "RNG DeInit Error"
@@ -1844,11 +1844,11 @@ msgstr "sistem file (filesystem) bersifat Read-only"
 
 #: ports/espressif/common-hal/espidf/__init__.c
 msgid "Received response was invalid"
-msgstr ""
+msgstr "Respon yang diterima tidak valid"
 
 #: supervisor/shared/bluetooth/bluetooth.c
 msgid "Reconnecting"
-msgstr ""
+msgstr "Menghubungkan kembali"
 
 #: shared-bindings/epaperdisplay/EPaperDisplay.c
 msgid "Refresh too soon"
@@ -1856,7 +1856,7 @@ msgstr "Segarkan terlalu cepat"
 
 #: shared-bindings/canio/RemoteTransmissionRequest.c
 msgid "RemoteTransmissionRequests limited to 8 bytes"
-msgstr ""
+msgstr "RemoteTransmissionRequests dibatasi hingga 8 byte"
 
 #: shared-bindings/aesio/aes.c
 msgid "Requested AES mode is unsupported"
@@ -1864,7 +1864,7 @@ msgstr "Mode AES yang diminta tidak didukung"
 
 #: ports/espressif/common-hal/espidf/__init__.c
 msgid "Requested resource not found"
-msgstr ""
+msgstr "Sumber yang diminta tidak ditemukan"
 
 #: ports/atmel-samd/common-hal/audioio/AudioOut.c
 msgid "Right channel unsupported"
@@ -1872,7 +1872,7 @@ msgstr "Channel Kanan tidak didukung"
 
 #: shared-module/jpegio/JpegDecoder.c
 msgid "Right format but not supported"
-msgstr ""
+msgstr "Format benar tapi tidak didukung"
 
 #: main.c
 msgid "Running in safe mode! Not running saved code.\n"
@@ -1882,7 +1882,7 @@ msgstr ""
 
 #: shared-module/sdcardio/SDCard.c
 msgid "SD card CSD format not supported"
-msgstr ""
+msgstr "Kartu SD Format CSD tidak didukung"
 
 #: ports/cxd56/common-hal/sdioio/SDCard.c
 msgid "SDCard init"
@@ -1901,7 +1901,7 @@ msgstr ""
 
 #: ports/espressif/common-hal/busio/SPI.c
 msgid "SPI configuration failed"
-msgstr ""
+msgstr "Konfigurasi SPI gagal"
 
 #: ports/stm/common-hal/busio/SPI.c
 msgid "SPI init error"
@@ -1909,7 +1909,7 @@ msgstr ""
 
 #: ports/raspberrypi/common-hal/busio/SPI.c
 msgid "SPI peripheral in use"
-msgstr ""
+msgstr "Periferal SPI sedang digunakan"
 
 #: ports/stm/common-hal/busio/SPI.c
 msgid "SPI re-init"
@@ -1917,12 +1917,12 @@ msgstr ""
 
 #: shared-bindings/is31fl3741/FrameBuffer.c
 msgid "Scale dimensions must divide by 3"
-msgstr ""
+msgstr "Skala dimensi harus dibagi 3"
 
 #: ports/espressif/common-hal/_bleio/Adapter.c
 #: ports/nordic/common-hal/_bleio/Adapter.c
 msgid "Scan already in progress. Stop with stop_scan."
-msgstr ""
+msgstr "Pemindaian sedang berjalan. Hentikan dengan stop_scan."
 
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audiobusio/PDMIn.c
@@ -1931,11 +1931,11 @@ msgstr "Serializer sedang digunakan"
 
 #: shared-bindings/ssl/SSLContext.c
 msgid "Server side context cannot have hostname"
-msgstr ""
+msgstr "Context server tidak mendukung hostname"
 
 #: ports/cxd56/common-hal/camera/Camera.c
 msgid "Size not supported"
-msgstr ""
+msgstr "Ukuran tidak didukung"
 
 #: shared-bindings/alarm/SleepMemory.c shared-bindings/memorymap/AddressRange.c
 #: shared-bindings/nvm/ByteArray.c
@@ -1952,7 +1952,7 @@ msgstr "Potongan tidak didukung"
 #: ports/espressif/common-hal/socketpool/SocketPool.c
 #: ports/raspberrypi/common-hal/socketpool/SocketPool.c
 msgid "SocketPool can only be used with wifi.radio"
-msgstr ""
+msgstr "SocketPool hanya dapat digunakan dengan wifi.radio"
 
 #: shared-bindings/aesio/aes.c
 msgid "Source and destination buffers must be the same length"
@@ -1960,19 +1960,19 @@ msgstr "Buffer sumber dan tujuan harus memiliki panjang yang sama"
 
 #: shared-bindings/paralleldisplaybus/ParallelBus.c
 msgid "Specify exactly one of data0 or data_pins"
-msgstr ""
+msgstr "Pilih hanya satu antara data0 atau data_pins"
 
 #: supervisor/shared/safe_mode.c
 msgid "Stack overflow. Increase stack size."
-msgstr ""
+msgstr "Stack overflow. Tambahkan ukuran stack."
 
 #: shared-bindings/alarm/time/TimeAlarm.c
 msgid "Supply one of monotonic_time or epoch_time"
-msgstr ""
+msgstr "Berikan salah satu dari monotonic_time atau epoch_time"
 
 #: shared-bindings/gnss/GNSS.c
 msgid "System entry must be gnss.SatelliteSystem"
-msgstr ""
+msgstr "Entri sistem harus berupa gnss.SatelliteSystem"
 
 #: ports/stm/common-hal/microcontroller/Processor.c
 msgid "Temperature read timed out"
@@ -1980,33 +1980,36 @@ msgstr "Waktu baca suhu habis"
 
 #: supervisor/shared/safe_mode.c
 msgid "The `microcontroller` module was used to boot into safe mode."
-msgstr ""
+msgstr "Modul `microcontroller` digunakan untuk boot ke mode aman."
 
 #: py/obj.c
 msgid "The above exception was the direct cause of the following exception:"
 msgstr ""
+"Pengecualian di atas adalah penyebab langsung dari pengecualian berikut:"
 
 #: shared-bindings/rgbmatrix/RGBMatrix.c
 msgid "The length of rgb_pins must be 6, 12, 18, 24, or 30"
-msgstr ""
+msgstr "Panjang rgb_pins harus 6, 12, 18, 24, atau 30"
 
 #: shared-module/audiodelays/Echo.c shared-module/audiomixer/MixerVoice.c
 msgid "The sample's %q does not match"
-msgstr ""
+msgstr "Sampel punya %q yang tidak cocok"
 
 #: supervisor/shared/safe_mode.c
 msgid "Third-party firmware fatal error."
-msgstr ""
+msgstr "Kesalahan fatal pada firmware pihak ketiga."
 
 #: shared-module/imagecapture/ParallelImageCapture.c
 msgid "This microcontroller does not support continuous capture."
-msgstr ""
+msgstr "Mikrokontroler ini tidak mendukung penangkapan berkelanjutan."
 
 #: shared-module/paralleldisplaybus/ParallelBus.c
 msgid ""
 "This microcontroller only supports data0=, not data_pins=, because it "
 "requires contiguous pins."
 msgstr ""
+"Mikrokontroler ini hanya mendukung data0=, bukan data_pins=, karena "
+"membutuhkan pin yang berurutan."
 
 #: shared-bindings/displayio/TileGrid.c
 msgid "Tile height must exactly divide bitmap height"
@@ -2022,17 +2025,18 @@ msgstr "Lebar ubin harus persis membagi lebar bitmap"
 
 #: shared-bindings/alarm/time/TimeAlarm.c
 msgid "Time is in the past."
-msgstr ""
+msgstr "Waktu sudah berlalu."
 
 #: ports/espressif/common-hal/_bleio/Adapter.c
 #: ports/nordic/common-hal/_bleio/Adapter.c
 #, c-format
 msgid "Timeout is too long: Maximum timeout length is %d seconds"
 msgstr ""
+"Waktu tunggu terlalu lama: Panjang maksimum waktu tunggu adalah %d detik"
 
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 msgid "Too many channels in sample"
-msgstr ""
+msgstr "Sampel memiliki terlalu banyak saluran"
 
 #: ports/raspberrypi/common-hal/audiobusio/I2SOut.c
 msgid "Too many channels in sample."
@@ -2040,11 +2044,13 @@ msgstr "Terlalu banyak channel dalam sampel"
 
 #: ports/espressif/common-hal/_bleio/Characteristic.c
 msgid "Too many descriptors"
-msgstr ""
+msgstr "Terlalu banyak deskriptor"
 
 #: shared-module/displayio/__init__.c
 msgid "Too many display busses; forgot displayio.release_displays() ?"
 msgstr ""
+"Terlalu banyak jalur tampilan; mungkin kamu lupa untuk panggil displayio."
+"release_displays()?"
 
 #: shared-module/displayio/__init__.c
 msgid "Too many displays"
@@ -2053,12 +2059,12 @@ msgstr "Terlalu banyak tampilan"
 #: ports/espressif/common-hal/_bleio/PacketBuffer.c
 #: ports/nordic/common-hal/_bleio/PacketBuffer.c
 msgid "Total data to write is larger than %q"
-msgstr ""
+msgstr "Total data yang akan ditulis lebih besar dari %q"
 
 #: ports/raspberrypi/common-hal/alarm/touch/TouchAlarm.c
 #: ports/stm/common-hal/alarm/touch/TouchAlarm.c
 msgid "Touch alarms not available"
-msgstr ""
+msgstr "Alarm sentuh tidak tersedia"
 
 #: py/obj.c
 msgid "Traceback (most recent call last):\n"
@@ -2075,7 +2081,7 @@ msgstr ""
 
 #: ports/raspberrypi/common-hal/busio/UART.c
 msgid "UART peripheral in use"
-msgstr ""
+msgstr "Periferal UART sedang digunakan"
 
 #: ports/stm/common-hal/busio/UART.c
 msgid "UART re-init"
@@ -2095,11 +2101,11 @@ msgstr ""
 
 #: supervisor/shared/safe_mode.c
 msgid "USB devices need more endpoints than are available."
-msgstr ""
+msgstr "Perangkat USB butuh lebih banyak endpoint daripada yang tersedia."
 
 #: supervisor/shared/safe_mode.c
 msgid "USB devices specify too many interface names."
-msgstr ""
+msgstr "Perangkat USB menggunakan terlalu banyak nama antarmuka."
 
 #: shared-module/usb_hid/Device.c
 msgid "USB error"
@@ -2119,7 +2125,7 @@ msgstr "Nilai UUID bukan str, int atau byte buffer"
 
 #: ports/raspberrypi/common-hal/memorymap/AddressRange.c
 msgid "Unable to access unaligned IO register"
-msgstr ""
+msgstr "Tidak dapat mengakses register IO yang tidak teratur"
 
 #: ports/atmel-samd/common-hal/audiobusio/I2SOut.c
 #: ports/atmel-samd/common-hal/audioio/AudioOut.c
@@ -2130,11 +2136,11 @@ msgstr "Tidak dapat mengalokasikan buffer untuk signed conversion"
 
 #: supervisor/shared/safe_mode.c
 msgid "Unable to allocate to the heap."
-msgstr ""
+msgstr "Tidak dapat mengalokasikan ke heap."
 
 #: ports/espressif/common-hal/busio/I2C.c
 msgid "Unable to create lock"
-msgstr ""
+msgstr "Tidak dapat membuat kunci"
 
 #: shared-module/i2cdisplaybus/I2CDisplayBus.c
 #: shared-module/is31fl3741/IS31FL3741.c
@@ -2153,7 +2159,7 @@ msgstr "Tidak dapat membaca data palet warna"
 #: ports/espressif/common-hal/mdns/Server.c
 #: ports/raspberrypi/common-hal/mdns/Server.c
 msgid "Unable to start mDNS query"
-msgstr ""
+msgstr "Tidak dapat memulai kueri mDNS"
 
 #: shared-bindings/nvm/ByteArray.c
 msgid "Unable to write to nvm."
@@ -2161,11 +2167,11 @@ msgstr "Tidak dapat menulis ke nvm."
 
 #: ports/raspberrypi/common-hal/memorymap/AddressRange.c
 msgid "Unable to write to read-only memory"
-msgstr ""
+msgstr "Tidak dapat menulis ke memori hanya-baca"
 
 #: shared-bindings/alarm/SleepMemory.c
 msgid "Unable to write to sleep_memory."
-msgstr ""
+msgstr "Tidak dapat menulis ke sleep_memory."
 
 #: ports/nordic/common-hal/_bleio/UUID.c
 msgid "Unexpected nrfx uuid type"
@@ -2174,23 +2180,23 @@ msgstr "Tipe urf nrfx tak sesuai"
 #: ports/espressif/common-hal/_bleio/__init__.c
 #, c-format
 msgid "Unknown BLE error at %s:%d: %d"
-msgstr ""
+msgstr "Kesalahan BLE tidak diketahui di %s:%d: %d"
 
 #: ports/espressif/common-hal/_bleio/__init__.c
 #, c-format
 msgid "Unknown BLE error: %d"
-msgstr ""
+msgstr "Kesalahan BLE tidak diketahui: %d"
 
 #: ports/espressif/common-hal/max3421e/Max3421E.c
 #: ports/raspberrypi/common-hal/wifi/__init__.c
 #, c-format
 msgid "Unknown error code %d"
-msgstr ""
+msgstr "Kode kesalahan tidak diketahui %d"
 
 #: shared-bindings/wifi/Radio.c
 #, c-format
 msgid "Unknown failure %d"
-msgstr ""
+msgstr "Kegagalan tidak diketahui %d"
 
 #: ports/nordic/common-hal/_bleio/__init__.c
 #, c-format
@@ -2210,17 +2216,17 @@ msgstr "Kesalahan keamanan tidak dikenal: 0x%04x"
 #: ports/espressif/common-hal/_bleio/__init__.c
 #, c-format
 msgid "Unknown system firmware error at %s:%d: %d"
-msgstr ""
+msgstr "Kesalahan firmware sistem tidak dikenal di %s:%d: %d"
 
 #: ports/nordic/common-hal/_bleio/__init__.c
 #, c-format
 msgid "Unknown system firmware error: %04x"
-msgstr ""
+msgstr "Kesalahan firmware sistem tidak diketahui: %04x"
 
 #: ports/espressif/common-hal/_bleio/__init__.c
 #, c-format
 msgid "Unknown system firmware error: %d"
-msgstr ""
+msgstr "Kesalahan firmware sistem tidak diketahui: %d"
 
 #: shared-bindings/adafruit_pixelbuf/PixelBuf.c
 #: shared-module/_pixelmap/PixelMap.c
@@ -2250,16 +2256,16 @@ msgstr "Format tidak didukung"
 
 #: shared-bindings/hashlib/__init__.c
 msgid "Unsupported hash algorithm"
-msgstr ""
+msgstr "Algoritma hash tidak didukung"
 
 #: ports/espressif/common-hal/socketpool/Socket.c
 msgid "Unsupported socket type"
-msgstr ""
+msgstr "Jenis soket tidak didukung"
 
 #: ports/espressif/common-hal/_bleio/Adapter.c
 #: ports/espressif/common-hal/dualbank/__init__.c
 msgid "Update failed"
-msgstr ""
+msgstr "Pembaruan gagal"
 
 #: ports/espressif/common-hal/_bleio/Characteristic.c
 #: ports/nordic/common-hal/_bleio/Characteristic.c
@@ -2275,7 +2281,7 @@ msgstr "Panjang nilai > max_length"
 
 #: ports/espressif/common-hal/espidf/__init__.c
 msgid "Version was invalid"
-msgstr ""
+msgstr "Versi tidak valid"
 
 #: ports/stm/common-hal/microcontroller/Processor.c
 msgid "Voltage read timed out"
@@ -2287,7 +2293,7 @@ msgstr "PERINGATAN: Nama file kode anda mempunyai dua ekstensi\n"
 
 #: ports/nordic/common-hal/watchdog/WatchDogTimer.c
 msgid "WatchDogTimer cannot be deinitialized once mode is set to RESET"
-msgstr ""
+msgstr "WatchDogTimer tidak dapat dideinisialisasi setelah mode diatur ke RESET"
 
 #: py/builtinhelp.c
 #, c-format
@@ -2298,6 +2304,11 @@ msgid ""
 "\n"
 "To list built-in modules type `help(\"modules\")`.\n"
 msgstr ""
+"Selamat datang di Adafruit CircuitPython %s!\n"
+"\n"
+"Kunjungi circuitpython.org untuk informasi lebih lanjut.\n"
+"\n"
+"Untuk membuat daftar modul bawaan, ketik `help(\"modules\")`.\n"
 
 #: supervisor/shared/web_workflow/web_workflow.c
 msgid "Wi-Fi: "
@@ -2305,7 +2316,7 @@ msgstr ""
 
 #: ports/raspberrypi/common-hal/wifi/Radio.c
 msgid "Wifi is not enabled"
-msgstr ""
+msgstr "Wifi tidak diaktifkan"
 
 #: main.c
 msgid "Woken up by alarm.\n"
@@ -2321,63 +2332,63 @@ msgstr "Menulis tidak didukung pada Karakteristik"
 #: ports/atmel-samd/boards/circuitplayground_express_displayio/mpconfigboard.h
 #: ports/atmel-samd/boards/meowmeow/mpconfigboard.h
 msgid "You pressed both buttons at start up."
-msgstr ""
+msgstr "Anda menekan kedua tombol saat memulai."
 
 #: ports/espressif/boards/m5stack_core_basic/mpconfigboard.h
 #: ports/espressif/boards/m5stack_core_fire/mpconfigboard.h
 #: ports/espressif/boards/m5stack_stick_c/mpconfigboard.h
 #: ports/espressif/boards/m5stack_stick_c_plus/mpconfigboard.h
 msgid "You pressed button A at start up."
-msgstr ""
+msgstr "Anda menekan tombol A saat memulai."
 
 #: ports/espressif/boards/m5stack_m5paper/mpconfigboard.h
 msgid "You pressed button DOWN at start up."
-msgstr ""
+msgstr "Anda menekan tombol DOWN saat memulai."
 
 #: supervisor/shared/safe_mode.c
 msgid "You pressed the BOOT button at start up"
-msgstr ""
+msgstr "Anda menekan tombol BOOT saat memulai"
 
 #: ports/espressif/boards/adafruit_feather_esp32c6_4mbflash_nopsram/mpconfigboard.h
 #: ports/espressif/boards/adafruit_itsybitsy_esp32/mpconfigboard.h
 msgid "You pressed the BOOT button at start up."
-msgstr ""
+msgstr "Anda menekan tombol BOOT saat memulai"
 
 #: ports/espressif/boards/adafruit_huzzah32_breakout/mpconfigboard.h
 msgid "You pressed the GPIO0 button at start up."
-msgstr ""
+msgstr "Anda menekan tombol GPIO0 saat memulai."
 
 #: ports/espressif/boards/espressif_esp32_lyrat/mpconfigboard.h
 msgid "You pressed the Rec button at start up."
-msgstr ""
+msgstr "Anda menekan tombol Rec saat memulai."
 
 #: ports/espressif/boards/adafruit_feather_esp32_v2/mpconfigboard.h
 msgid "You pressed the SW38 button at start up."
-msgstr ""
+msgstr "Anda menekan tombol SW38 saat memulai."
 
 #: ports/espressif/boards/hardkernel_odroid_go/mpconfigboard.h
 #: ports/espressif/boards/vidi_x/mpconfigboard.h
 msgid "You pressed the VOLUME button at start up."
-msgstr ""
+msgstr "Anda menekan tombol VOLUME saat memulai."
 
 #: ports/espressif/boards/m5stack_atom_echo/mpconfigboard.h
 #: ports/espressif/boards/m5stack_atom_lite/mpconfigboard.h
 #: ports/espressif/boards/m5stack_atom_matrix/mpconfigboard.h
 #: ports/espressif/boards/m5stack_atom_u/mpconfigboard.h
 msgid "You pressed the central button at start up."
-msgstr ""
+msgstr "Anda menekan tombol tengah saat memulai."
 
 #: ports/nordic/boards/aramcon2_badge/mpconfigboard.h
 msgid "You pressed the left button at start up."
-msgstr ""
+msgstr "Anda menekan tombol kiri saat memulai."
 
 #: supervisor/shared/safe_mode.c
 msgid "You pressed the reset button during boot."
-msgstr ""
+msgstr "Anda menekan tombol reset saat memulai."
 
 #: supervisor/shared/micropython.c
 msgid "[truncated due to length]"
-msgstr ""
+msgstr "[terpotong karena kepanjangan]"
 
 #: py/objtype.c
 msgid "__init__() should return None"
@@ -2402,11 +2413,11 @@ msgstr "alamatnya kosong"
 
 #: py/compile.c
 msgid "annotation must be an identifier"
-msgstr ""
+msgstr "anotasi harus merupakan pengidentifikasi"
 
 #: extmod/ulab/code/numpy/create.c
 msgid "arange: cannot compute length"
-msgstr ""
+msgstr "arange: tidak dapat menghitung panjang"
 
 #: py/modbuiltins.c
 msgid "arg is an empty sequence"
@@ -2414,7 +2425,7 @@ msgstr "arg berisi urutan kosong"
 
 #: py/objobject.c
 msgid "arg must be user-type"
-msgstr ""
+msgstr "arg harus bertipe user-type"
 
 #: extmod/ulab/code/numpy/numerical.c
 msgid "argsort argument must be an ndarray"
diff --git a/ports/broadcom/mpconfigport.mk b/ports/broadcom/mpconfigport.mk
index 543e174683617..b4b3e2ebf8192 100644
--- a/ports/broadcom/mpconfigport.mk
+++ b/ports/broadcom/mpconfigport.mk
@@ -25,3 +25,9 @@ USB_NUM_ENDPOINT_PAIRS = 8
 USB_HIGHSPEED = 1
 
 CIRCUITPY_BUILD_EXTENSIONS ?= disk.img.zip,kernel8.img
+
+ifeq ($(CHIP_VARIANT), "bcm2711")
+CIRCUITPY_MIN_GCC_VERSION ?= 10
+else ifeq ($(CHIP_VARIANT), "bcm2837")
+CIRCUITPY_MIN_GCC_VERSION ?= 10
+endif
diff --git a/ports/litex/mpconfigport.mk b/ports/litex/mpconfigport.mk
index d8dc4eef1edcd..a93a3890bbc9a 100644
--- a/ports/litex/mpconfigport.mk
+++ b/ports/litex/mpconfigport.mk
@@ -31,3 +31,4 @@ CIRCUITPY_USB_HID = 1
 CIRCUITPY_USB_MIDI = 1
 
 CIRCUITPY_BUILD_EXTENSIONS ?= dfu
+CIRCUITPY_MIN_GCC_VERSION ?= 8
diff --git a/ports/raspberrypi/common-hal/microcontroller/Processor.c b/ports/raspberrypi/common-hal/microcontroller/Processor.c
index 678ceefbf92ff..139edc999d669 100644
--- a/ports/raspberrypi/common-hal/microcontroller/Processor.c
+++ b/ports/raspberrypi/common-hal/microcontroller/Processor.c
@@ -39,7 +39,7 @@
 float common_hal_mcu_processor_get_temperature(void) {
     adc_init();
     adc_set_temp_sensor_enabled(true);
-    adc_select_input(4);
+    adc_select_input(ADC_TEMPERATURE_CHANNEL_NUM);
     uint16_t value = adc_read();
     adc_set_temp_sensor_enabled(false);
     float voltage = value * 3.3 / (1 << 12);
diff --git a/ports/raspberrypi/common-hal/nvm/ByteArray.c b/ports/raspberrypi/common-hal/nvm/ByteArray.c
index 541f1a34bd7cf..2905a624c29b5 100644
--- a/ports/raspberrypi/common-hal/nvm/ByteArray.c
+++ b/ports/raspberrypi/common-hal/nvm/ByteArray.c
@@ -12,6 +12,7 @@
 #include "py/runtime.h"
 #include "src/rp2_common/hardware_flash/include/hardware/flash.h"
 #include "shared-bindings/microcontroller/__init__.h"
+#include "supervisor/internal_flash.h"
 
 extern uint32_t __flash_binary_start;
 static const uint32_t flash_binary_start = (uint32_t)&__flash_binary_start;
@@ -28,14 +29,18 @@ static void write_page(uint32_t page_addr, uint32_t offset, uint32_t len, uint8_
     if (offset == 0 && len == FLASH_PAGE_SIZE) {
         // disable interrupts to prevent core hang on rp2040
         common_hal_mcu_disable_interrupts();
+        supervisor_flash_pre_write();
         flash_range_program(RMV_OFFSET(page_addr), bytes, FLASH_PAGE_SIZE);
+        supervisor_flash_post_write();
         common_hal_mcu_enable_interrupts();
     } else {
         uint8_t buffer[FLASH_PAGE_SIZE];
         memcpy(buffer, (uint8_t *)page_addr, FLASH_PAGE_SIZE);
         memcpy(buffer + offset, bytes, len);
         common_hal_mcu_disable_interrupts();
+        supervisor_flash_pre_write();
         flash_range_program(RMV_OFFSET(page_addr), buffer, FLASH_PAGE_SIZE);
+        supervisor_flash_post_write();
         common_hal_mcu_enable_interrupts();
     }
 
@@ -57,8 +62,10 @@ static void erase_and_write_sector(uint32_t address, uint32_t len, uint8_t *byte
     memcpy(buffer + address, bytes, len);
     // disable interrupts to prevent core hang on rp2040
     common_hal_mcu_disable_interrupts();
+    supervisor_flash_pre_write();
     flash_range_erase(RMV_OFFSET(CIRCUITPY_INTERNAL_NVM_START_ADDR), FLASH_SECTOR_SIZE);
     flash_range_program(RMV_OFFSET(CIRCUITPY_INTERNAL_NVM_START_ADDR), buffer, FLASH_SECTOR_SIZE);
+    supervisor_flash_post_write();
     common_hal_mcu_enable_interrupts();
 }
 
diff --git a/ports/raspberrypi/lib/cyw43-driver b/ports/raspberrypi/lib/cyw43-driver
index 9f6405f0b3260..faf36381bad1f 160000
--- a/ports/raspberrypi/lib/cyw43-driver
+++ b/ports/raspberrypi/lib/cyw43-driver
@@ -1 +1 @@
-Subproject commit 9f6405f0b3260968306d782e1c5ac275a46dc65d
+Subproject commit faf36381bad1f668a30172b6336c9a970966ef4c
diff --git a/ports/raspberrypi/supervisor/internal_flash.c b/ports/raspberrypi/supervisor/internal_flash.c
index 1b328cbc5a7bb..563795c516a9b 100644
--- a/ports/raspberrypi/supervisor/internal_flash.c
+++ b/ports/raspberrypi/supervisor/internal_flash.c
@@ -46,16 +46,14 @@ static uint32_t m1_rfmt;
 static uint32_t m1_timing;
 #endif
 
-static void save_psram_settings(void) {
+static void __no_inline_not_in_flash_func(save_psram_settings)(void) {
     #ifdef PICO_RP2350
     // We're about to invalidate the XIP cache, clean it first to commit any dirty writes to PSRAM
-    volatile uint8_t *maintenance_ptr = (uint8_t *)XIP_MAINTENANCE_BASE;
-    for (int i = 1; i < 16 * 1024; i += 8) {
-        // Background info: https://forums.raspberrypi.com/viewtopic.php?t=378249
-        maintenance_ptr[i] = 0; // Clean
-        __compiler_memory_barrier();
-        maintenance_ptr[i - 1] = 0; // Explicitly invalidate
-        __compiler_memory_barrier();
+    // From https://forums.raspberrypi.com/viewtopic.php?t=378249#p2263677
+    // Perform clean-by-set/way on all lines
+    for (uint32_t i = 0; i < 2048; ++i) {
+        // Use the upper 16k of the maintenance space (0x1bffc000 through 0x1bffffff):
+        *(volatile uint8_t *)(XIP_SRAM_BASE + (XIP_MAINTENANCE_BASE - XIP_BASE) + i * 8u + 0x1u) = 0;
     }
 
     m1_timing = qmi_hw->m[1].timing;
@@ -63,13 +61,22 @@ static void save_psram_settings(void) {
     #endif
 }
 
-static void restore_psram_settings(void) {
+static void __no_inline_not_in_flash_func(restore_psram_settings)(void) {
     #ifdef PICO_RP2350
     qmi_hw->m[1].timing = m1_timing;
     qmi_hw->m[1].rfmt = m1_rfmt;
+    __compiler_memory_barrier();
     #endif
 }
 
+void supervisor_flash_pre_write(void) {
+    save_psram_settings();
+}
+
+void supervisor_flash_post_write(void) {
+    restore_psram_settings();
+}
+
 void supervisor_flash_init(void) {
     bi_decl_if_func_used(bi_block_device(
         BINARY_INFO_MAKE_TAG('C', 'P'),
@@ -84,9 +91,9 @@ void supervisor_flash_init(void) {
     // Read the RDID register to get the flash capacity.
     uint8_t cmd[] = {0x9f, 0, 0, 0};
     uint8_t data[4];
-    save_psram_settings();
+    supervisor_flash_pre_write();
     flash_do_cmd(cmd, data, 4);
-    restore_psram_settings();
+    supervisor_flash_post_write();
     uint8_t power_of_two = FLASH_DEFAULT_POWER_OF_TWO;
     // Flash must be at least 2MB (1 << 21) because we use the first 1MB for the
     // CircuitPython core. We validate the range because Adesto Tech flash chips
@@ -116,10 +123,10 @@ void port_internal_flash_flush(void) {
     #if CIRCUITPY_AUDIOCORE
     uint32_t channel_mask = audio_dma_pause_all();
     #endif
-    save_psram_settings();
+    supervisor_flash_pre_write();
     flash_range_erase(CIRCUITPY_CIRCUITPY_DRIVE_START_ADDR + _cache_lba, SECTOR_SIZE);
     flash_range_program(CIRCUITPY_CIRCUITPY_DRIVE_START_ADDR + _cache_lba, _cache, SECTOR_SIZE);
-    restore_psram_settings();
+    supervisor_flash_post_write();
     _cache_lba = NO_CACHE;
     #if CIRCUITPY_AUDIOCORE
     audio_dma_unpause_mask(channel_mask);
diff --git a/ports/raspberrypi/supervisor/internal_flash.h b/ports/raspberrypi/supervisor/internal_flash.h
index 01acbf02b4de4..a7941b17c470f 100644
--- a/ports/raspberrypi/supervisor/internal_flash.h
+++ b/ports/raspberrypi/supervisor/internal_flash.h
@@ -9,6 +9,10 @@
 
 #include "mpconfigport.h"
 
+// These must be called before and after doing a low-level flash write.
+void supervisor_flash_pre_write(void);
+void supervisor_flash_post_write(void);
+
 // #define INTERNAL_FLASH_PART1_NUM_BLOCKS (CIRCUITPY_INTERNAL_FLASH_FILESYSTEM_SIZE / FILESYSTEM_BLOCK_SIZE)
 
 // #define INTERNAL_FLASH_SYSTICK_MASK    (0x1ff) // 512ms
diff --git a/ports/raspberrypi/supervisor/port.c b/ports/raspberrypi/supervisor/port.c
index 13e5abb61216a..b9697a0f83fd0 100644
--- a/ports/raspberrypi/supervisor/port.c
+++ b/ports/raspberrypi/supervisor/port.c
@@ -326,8 +326,6 @@ safe_mode_t port_init(void) {
     // Reset everything into a known state before board_init.
     reset_port();
 
-    serial_early_init();
-
     #ifdef CIRCUITPY_PSRAM_CHIP_SELECT
     setup_psram();
     #endif
diff --git a/ports/stm/Makefile b/ports/stm/Makefile
index d42ebdc727612..972bd66bcab9f 100755
--- a/ports/stm/Makefile
+++ b/ports/stm/Makefile
@@ -165,7 +165,7 @@ endif
 
 # Need this to avoid UART linker problems. TODO: rewrite to use registered callbacks.
 # Does not exist for F4 and lower
-ifeq ($(MCU_VARIANT),$(filter $(MCU_VARIANT),STM32F765xx STM32F767xx STM32F769xx STM32H743xx STM32L4R5xx))
+ifeq ($(MCU_VARIANT),$(filter $(MCU_VARIANT),STM32F765xx STM32F767xx STM32F769xx STM32H743xx STM32L4R5xx STM32L433xx))
 	SRC_STM32 += $(HAL_DIR)/Src/stm32$(MCU_SERIES_LOWER)xx_hal_uart_ex.c
 endif
 
@@ -197,7 +197,11 @@ ifneq ($(CIRCUITPY_AUDIOBUSIO_PDMIN),0)
 endif
 
 ifneq ($(CIRCUITPY_USB),0)
-SRC_C += lib/tinyusb/src/portable/synopsys/dwc2/dcd_dwc2.c
+	ifeq ($(MCU_VARIANT_LOWER),stm32l433xx)
+		SRC_C += lib/tinyusb/src/portable/st/stm32_fsdev/dcd_stm32_fsdev.c
+	else
+		SRC_C += lib/tinyusb/src/portable/synopsys/dwc2/dcd_dwc2.c
+	endif
 endif
 
 SRC_S = \
diff --git a/ports/stm/boards/STM32L433_boot.ld b/ports/stm/boards/STM32L433_boot.ld
new file mode 100644
index 0000000000000..161d883160c2c
--- /dev/null
+++ b/ports/stm/boards/STM32L433_boot.ld
@@ -0,0 +1,27 @@
+/*
+    GNU linker script for STM32L433 with bootloader
+*/
+
+/* Specify the memory areas */
+MEMORY
+{
+    FLASH (rx)          : ORIGIN = 0x08000000, LENGTH = 256k /* entire flash */
+    FLASH_ISR (rx)      : ORIGIN = 0x08010000, LENGTH = 4K /* ISR vector. Kind of wasteful. */
+    FLASH_FIRMWARE (rx) : ORIGIN = 0x08011000, LENGTH = 192K-64K-4K  /* For now, limit to 1MB so that bank switching is still possible. */
+    FLASH_FS (rw)       : ORIGIN = 0x08030000, LENGTH = 60K
+    RAM (xrw)           : ORIGIN = 0x20000000, LENGTH = 640K
+}
+
+
+/* produce a link error if there is not this amount of RAM for these sections */
+_minimum_stack_size = 24K;
+_minimum_heap_size = 16K;
+
+/* Define the top end of the stack.  The stack is full descending so begins just
+   above last byte of RAM.  Note that EABI requires the stack to be 8-byte
+   aligned for a call. */
+_estack = ORIGIN(RAM) + LENGTH(RAM);
+
+/* RAM extents for the garbage collector */
+_ram_start = ORIGIN(RAM);
+_ram_end = ORIGIN(RAM) + LENGTH(RAM);
diff --git a/ports/stm/boards/STM32L433_default.ld b/ports/stm/boards/STM32L433_default.ld
new file mode 100644
index 0000000000000..886a1b8827a20
--- /dev/null
+++ b/ports/stm/boards/STM32L433_default.ld
@@ -0,0 +1,29 @@
+/*
+    GNU linker script for STM32L433 with filesystem
+*/
+
+/* Specify the memory areas */
+MEMORY
+{
+    FLASH (rx)          : ORIGIN = 0x08000000, LENGTH = 256K /* entire flash */
+    FLASH_ISR (rx)      : ORIGIN = 0x08000000, LENGTH = 16K /* ISR vector. */
+    FLASH_FS (rw)       : ORIGIN = 0x08004000, LENGTH = 48K
+    FLASH_FIRMWARE (rx) : ORIGIN = 0x08010000, LENGTH = 256K - 48K - 16K
+    RAM (xrw)           : ORIGIN = 0x20000000, LENGTH = 64K
+}
+
+/* produce a link error if there is not this amount of RAM for these sections */
+_minimum_stack_size = 24K;
+_minimum_heap_size = 16K;
+
+/* Define the top end of the stack.  The stack is full descending so begins just
+   above last byte of RAM.  Note that EABI requires the stack to be 8-byte
+   aligned for a call. */
+_estack = ORIGIN(RAM) + LENGTH(RAM);
+
+/* RAM extents for the garbage collector */
+_ram_start = ORIGIN(RAM);
+_ram_end = ORIGIN(RAM) + LENGTH(RAM);
+
+/* ensure the firmware is within bounds */
+ASSERT ( (ORIGIN(FLASH_FIRMWARE) + LENGTH(FLASH_FIRMWARE)) <= (ORIGIN(FLASH)+LENGTH(FLASH)), "FLASH_FIRMWARE out of bounds" );
diff --git a/ports/stm/boards/STM32L4R5_default.ld b/ports/stm/boards/STM32L4R5_default.ld
index 1bffcee04ed65..b58db53b37696 100644
--- a/ports/stm/boards/STM32L4R5_default.ld
+++ b/ports/stm/boards/STM32L4R5_default.ld
@@ -16,7 +16,7 @@ MEMORY
 _minimum_stack_size = 24K;
 _minimum_heap_size = 16K;
 
-/* Define tho top end of the stack.  The stack is full descending so begins just
+/* Define the top end of the stack.  The stack is full descending so begins just
    above last byte of RAM.  Note that EABI requires the stack to be 8-byte
    aligned for a call. */
 _estack = ORIGIN(RAM) + LENGTH(RAM);
diff --git a/ports/stm/boards/cygnet/board.c b/ports/stm/boards/cygnet/board.c
new file mode 100644
index 0000000000000..f6650fb8f9c33
--- /dev/null
+++ b/ports/stm/boards/cygnet/board.c
@@ -0,0 +1,79 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+
+#include "supervisor/board.h"
+#include "mpconfigboard.h"
+
+#include "stm32l4xx.h"
+#include "stm32l433xx.h"
+
+#include "shared-bindings/microcontroller/Pin.h"
+#include "shared-bindings/digitalio/DigitalInOut.h"
+#include "shared-bindings/digitalio/Direction.h"
+#include "shared-bindings/digitalio/DriveMode.h"
+#include "board.h"
+
+digitalio_digitalinout_obj_t power_pin = { .base.type = &digitalio_digitalinout_type };
+digitalio_digitalinout_obj_t discharge_pin = { .base.type = &digitalio_digitalinout_type };
+
+void initialize_discharge_pin(void) {
+    /* Initialize the 3V3 discharge to be OFF and the output power to be ON */
+    __HAL_RCC_GPIOA_CLK_ENABLE();
+    __HAL_RCC_GPIOH_CLK_ENABLE();
+    __HAL_RCC_GPIOB_CLK_ENABLE();
+
+    common_hal_digitalio_digitalinout_construct(&power_pin, &pin_PH00);
+    common_hal_digitalio_digitalinout_construct(&discharge_pin, &pin_PH01);
+    common_hal_digitalio_digitalinout_never_reset(&power_pin);
+    common_hal_digitalio_digitalinout_never_reset(&discharge_pin);
+
+    GPIO_InitTypeDef GPIO_InitStruct;
+
+    /* Set DISCHARGE_3V3 as well as the pins we're not initially using to FLOAT */
+    GPIO_InitStruct.Mode = GPIO_MODE_ANALOG;
+    GPIO_InitStruct.Pull = GPIO_NOPULL;
+    GPIO_InitStruct.Pin = GPIO_PIN_1;
+    HAL_GPIO_Init(GPIOH, &GPIO_InitStruct); /* PH1 DISCHARGE_3V3 */
+    GPIO_InitStruct.Pin = GPIO_PIN_3;
+    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct); /* PB3 is USB_DETECT */
+    GPIO_InitStruct.Pin = GPIO_PIN_15;
+    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct); /* PA15 is CHARGE_DETECT */
+    GPIO_InitStruct.Pin = GPIO_PIN_4;
+    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct); /* PA4 is BAT_VOLTAGE */
+
+    /* Turn on the 3V3 regulator */
+    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+    GPIO_InitStruct.Speed = GPIO_SPEED_LOW;
+    GPIO_InitStruct.Pin = GPIO_PIN_0;
+    HAL_GPIO_Init(GPIOH, &GPIO_InitStruct);
+    HAL_GPIO_WritePin(GPIOH, GPIO_InitStruct.Pin, GPIO_PIN_SET);
+}
+
+void board_init(void) {
+    // enable the debugger while sleeping. Todo move somewhere more central (kind of generally useful in a debug build)
+    SET_BIT(DBGMCU->CR, DBGMCU_CR_DBG_SLEEP);
+
+    //  Set tick interrupt priority, default HAL value is intentionally invalid
+    //  Without this, USB does not function.
+    HAL_InitTick((1UL << __NVIC_PRIO_BITS) - 1UL);
+
+    __HAL_RCC_GPIOA_CLK_ENABLE();
+    GPIO_InitTypeDef GPIO_InitStruct;
+    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
+    GPIO_InitStruct.Pull = GPIO_NOPULL;
+    GPIO_InitStruct.Speed = GPIO_SPEED_LOW;
+    GPIO_InitStruct.Pin = GPIO_PIN_8;
+    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
+    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_8, GPIO_PIN_SET);
+    HAL_Delay(50);
+    HAL_GPIO_WritePin(GPIOA, GPIO_PIN_8, GPIO_PIN_RESET);
+}
+
+void reset_board(void) {
+    initialize_discharge_pin();
+}
+
+// Use the MP_WEAK supervisor/shared/board.c versions of routines not defined here.
diff --git a/ports/stm/boards/cygnet/board.h b/ports/stm/boards/cygnet/board.h
new file mode 100644
index 0000000000000..ce199359ba496
--- /dev/null
+++ b/ports/stm/boards/cygnet/board.h
@@ -0,0 +1,12 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "common-hal/digitalio/DigitalInOut.h"
+
+extern digitalio_digitalinout_obj_t power_pin;
+extern digitalio_digitalinout_obj_t discharge_pin;
diff --git a/ports/stm/boards/cygnet/mpconfigboard.h b/ports/stm/boards/cygnet/mpconfigboard.h
new file mode 100644
index 0000000000000..f3b1fcc2eb72c
--- /dev/null
+++ b/ports/stm/boards/cygnet/mpconfigboard.h
@@ -0,0 +1,47 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2024 Blues Wireless Contributors.
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+// Micropython setup
+
+#define MICROPY_HW_BOARD_NAME       "Cygnet"
+#define MICROPY_HW_MCU_NAME         "STM32L433CCT6"
+
+#define MICROPY_PY_SYS_PLATFORM     MICROPY_HW_BOARD_NAME
+
+#define STM32L433XX
+#define BOARD_CYGNET
+
+#define LSE_VALUE ((uint32_t)32768)
+#define BOARD_HAS_LOW_SPEED_CRYSTAL (1)
+#define BOARD_HAS_HIGH_SPEED_CRYSTAL (0)
+
+// Increase drive strength of 32kHz external crystal, in line with calculations specified in ST AN2867 sections 3.3, 3.4, and STM32L4 datasheet DS12023 Table 58. LSE oscillator characteristics.
+// The drive strength RCC_LSEDRIVE_LOW is marginal for the 32kHz crystal oscillator stability, and RCC_LSEDRIVE_MEDIUMLOW meets the calculated drive strength with a small margin for parasitic capacitance.
+#define BOARD_LSE_DRIVE_LEVEL RCC_LSEDRIVE_MEDIUMLOW
+
+// Bootloader only
+#ifdef UF2_BOOTLOADER_ENABLED
+    #define BOARD_VTOR_DEFER (1) // Leave VTOR relocation to bootloader
+#endif
+
+#define BOARD_NO_VBUS_SENSE (1)
+#define BOARD_NO_USB_OTG_ID_SENSE (1)
+
+#define DEFAULT_I2C_BUS_SCL (&pin_PB06)
+#define DEFAULT_I2C_BUS_SDA (&pin_PB07)
+
+#define DEFAULT_SPI_BUS_SS (&pin_PB08)
+#define DEFAULT_SPI_BUS_SCK (&pin_PA05)
+#define DEFAULT_SPI_BUS_MOSI (&pin_PB05)
+#define DEFAULT_SPI_BUS_MISO (&pin_PB06)
+
+#define DEFAULT_UART_BUS_RX (&pin_PA10)
+#define DEFAULT_UART_BUS_TX (&pin_PA09)
+
+#define CYGNET_DISCHARGE_3V3 (&pin_PH01)
+#define CYGNET_ENABLE_3V3 (&pin_PH00)
diff --git a/ports/stm/boards/cygnet/mpconfigboard.mk b/ports/stm/boards/cygnet/mpconfigboard.mk
new file mode 100644
index 0000000000000..df5648b04d03d
--- /dev/null
+++ b/ports/stm/boards/cygnet/mpconfigboard.mk
@@ -0,0 +1,105 @@
+USB_VID = 0x30A4
+USB_PID = 0x03
+USB_PRODUCT = "Cygnet"
+USB_MANUFACTURER = "Blues Inc."
+
+MCU_SERIES = L4
+MCU_VARIANT = STM32L433xx
+MCU_PACKAGE = LQFP48
+
+LD_COMMON = boards/common_default.ld
+LD_DEFAULT = boards/STM32L433_default.ld
+UF2_OFFSET = 0x8010000
+UF2_BOOTLOADER ?= 1
+CIRCUITPY_BUILD_EXTENSIONS = bin,uf2
+
+INTERNAL_FLASH_FILESYSTEM = 1
+LONGINT_IMPL = NONE
+CIRCUITPY_FULL_BUILD = 0
+
+CIRCUITPY_AESIO = 0
+CIRCUITPY_ALARM = 0
+CIRCUITPY_ANALOGIO = 1
+CIRCUITPY_ATEXIT = 0
+CIRCUITPY_AUDIOBUSIO = 0
+CIRCUITPY_AUDIOBUSIO_I2SOUT = 0
+CIRCUITPY_AUDIOBUSIO_PDMIN = 0
+CIRCUITPY_AUDIOMIXER = 0
+CIRCUITPY_AUDIOMP3 = 0
+CIRCUITPY_AUDIOPWMIO = 0
+CIRCUITPY_BITBANGIO = 1
+CIRCUITPY_BLEIO = 0
+CIRCUITPY_BLEIO_HCI = 0
+CIRCUITPY_BINASCII = 0
+CIRCUITPY_BITMAPFILTER = 0
+CIRCUITPY_BITMAPTOOLS = 0
+CIRCUITPY_BUILTINS_POW3 = 0
+CIRCUITPY_BUSDEVICE = 0
+CIRCUITPY_BUSIO = 1
+CIRCUITPY_CANIO = 0
+CIRCUITPY_COMPUTED_GOTO_SAVE_SPACE = 1
+CIRCUITPY_COUNTIO = 0
+CIRCUITPY_DIGITALIO = 1
+CIRCUITPY_DISPLAYIO = 0
+CIRCUITPY_ENABLE_MPY_NATIVE = 0
+CIRCUITPY_FRAMEBUFFERIO = 0
+CIRCUITPY_FREQUENCYIO = 0
+CIRCUITPY_FUTURE= 0
+CIRCUITPY_GETPASS = 0
+CIRCUITPY_GIFIO = 0
+CIRCUITPY_I2CTARGET = 0
+CIRCUITPY_JSON = 0
+CIRCUITPY_KEYPAD = 0
+CIRCUITPY_KEYPAD_DEMUX = 0
+CIRCUITPY_LTO = 1
+CIRCUITPY_MICROCONTROLLER = 1
+CIRCUITPY_MSGPACK = 0
+CIRCUITPY_NEOPIXEL_WRITE = 0
+CIRCUITPY_NVM = 0
+CIRCUITPY_ONEWIREIO = 0
+CIRCUITPY_OS = 1
+CIRCUITPY_PIXELBUF = 0
+CIRCUITPY_PIXELMAP = 0
+CIRCUITPY_PULSEIO = 1
+CIRCUITPY_PWMIO = 1
+CIRCUITPY_RANDOM = 0
+CIRCUITPY_RAINBOWIO = 0
+CIRCUITPY_RE = 0
+CIRCUITPY_REQUIRE_I2C_PULLUPS = 0
+CIRCUITPY_ROTARYIO_SOFTENCODER = 1
+CIRCUITPY_RGBMATRIX = 0
+CIRCUITPY_RTC = 0
+CIRCUITPY_SAFEMODE_PY = 0
+CIRCUITPY_SDCARDIO = 0
+CIRCUITPY_STATUS_BAR= 0
+CIRCUITPY_STORAGE = 1
+CIRCUITPY_SUPERVISOR = 1
+CIRCUITPY_SYNTHIO = 0
+CIRCUITPY_TERMINALIO = 0
+CIRCUITPY_TOUCHIO = 0
+CIRCUITPY_TOUCHIO_USE_NATIVE = 1
+CIRCUITPY_TRACEBACK = 0
+CIRCUITPY_ULAB = 0
+CIRCUITPY_USB_CDC = 1
+CIRCUITPY_USB_HID = 0
+CIRCUITPY_USB_IDENTIFICATION = 1
+CIRCUITPY_USB_MIDI = 0
+CIRCUITPY_USB_MIDI_ENABLED_DEFAULT= 0
+CIRCUITPY_USB_MSC = 1
+CIRCUITPY_USB_VENDOR = 0
+CIRCUITPY_WIFI_RADIO_SETTABLE_MAC_ADDRESS= 0
+CIRCUITPY_VECTORIO = 0
+CIRCUITPY_ZLIB = 0
+
+MICROPY_PY_ASYNC_AWAIT = 0
+
+RELEASE_NEEDS_CLEAN_BUILD = 0
+
+SUPEROPT_GC = 0
+SUPEROPT_VM = 0
+
+CIRCUITPY_LTO_PARTITION = one
+
+OPTIMIZATION_FLAGS = -Os
+
+CFLAGS_BOARD = -fweb -frename-registers
diff --git a/ports/stm/boards/cygnet/pins.c b/ports/stm/boards/cygnet/pins.c
new file mode 100644
index 0000000000000..f644160e4fd2a
--- /dev/null
+++ b/ports/stm/boards/cygnet/pins.c
@@ -0,0 +1,52 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+
+// #include "py/objtuple.h"
+#include "shared-bindings/board/__init__.h"
+#include "board.h"
+
+// Core Feather Pins
+static const mp_rom_map_elem_t board_module_globals_table[] = {
+    CIRCUITPYTHON_BOARD_DICT_STANDARD_ITEMS
+
+    { MP_ROM_QSTR(MP_QSTR_ENABLE_3V3), &power_pin },
+    { MP_ROM_QSTR(MP_QSTR_DISCHARGE_3V3), &discharge_pin },
+
+    { MP_ROM_QSTR(MP_QSTR_A0), MP_ROM_PTR(&pin_PA00) },
+    { MP_ROM_QSTR(MP_QSTR_A1), MP_ROM_PTR(&pin_PA01) },
+    { MP_ROM_QSTR(MP_QSTR_A2), MP_ROM_PTR(&pin_PA02) },
+    { MP_ROM_QSTR(MP_QSTR_A3), MP_ROM_PTR(&pin_PA03) },
+    { MP_ROM_QSTR(MP_QSTR_A4), MP_ROM_PTR(&pin_PB01) },
+    { MP_ROM_QSTR(MP_QSTR_A5), MP_ROM_PTR(&pin_PA07) },
+
+    { MP_ROM_QSTR(MP_QSTR_VOLTAGE_MONITOR), MP_ROM_PTR(&pin_PA04) },
+    { MP_ROM_QSTR(MP_QSTR_BUTTON_USR), MP_ROM_PTR(&pin_PC13) },
+
+    { MP_ROM_QSTR(MP_QSTR_D5), MP_ROM_PTR(&pin_PB08) },
+    { MP_ROM_QSTR(MP_QSTR_D6), MP_ROM_PTR(&pin_PB09) },
+    { MP_ROM_QSTR(MP_QSTR_D9), MP_ROM_PTR(&pin_PB14) },
+    { MP_ROM_QSTR(MP_QSTR_D12), MP_ROM_PTR(&pin_PB15) },
+
+    { MP_ROM_QSTR(MP_QSTR_LED), MP_ROM_PTR(&pin_PA08) },
+    { MP_ROM_QSTR(MP_QSTR_D13), MP_ROM_PTR(&pin_PB04) },   // ADC, PWM, DAC2 output also
+
+    { MP_ROM_QSTR(MP_QSTR_SDA), MP_ROM_PTR(&pin_PB07) },    // PWM
+    { MP_ROM_QSTR(MP_QSTR_SCL), MP_ROM_PTR(&pin_PB06) },    // PWM
+
+    { MP_ROM_QSTR(MP_QSTR_SS), MP_ROM_PTR(&pin_PB08) },
+    { MP_ROM_QSTR(MP_QSTR_SCK), MP_ROM_PTR(&pin_PA14) },
+    { MP_ROM_QSTR(MP_QSTR_MISO), MP_ROM_PTR(&pin_PA13) },
+    { MP_ROM_QSTR(MP_QSTR_MOSI), MP_ROM_PTR(&pin_PB05) },
+
+    { MP_ROM_QSTR(MP_QSTR_TX), MP_ROM_PTR(&pin_PA09) },     // ADC, PWM
+    { MP_ROM_QSTR(MP_QSTR_RX), MP_ROM_PTR(&pin_PA10) },     // PWM
+
+    { MP_ROM_QSTR(MP_QSTR_I2C), MP_ROM_PTR(&board_i2c_obj) },
+    { MP_ROM_QSTR(MP_QSTR_SPI), MP_ROM_PTR(&board_spi_obj) },
+    { MP_ROM_QSTR(MP_QSTR_UART), MP_ROM_PTR(&board_uart_obj) },
+};
+
+MP_DEFINE_CONST_DICT(board_module_globals, board_module_globals_table);
diff --git a/ports/stm/boards/cygnet/tests/analog_output.py b/ports/stm/boards/cygnet/tests/analog_output.py
new file mode 100644
index 0000000000000..6af931e65d6fa
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/analog_output.py
@@ -0,0 +1,85 @@
+import board
+import analogio
+import digitalio
+
+
+def test_dac_analog(p_in, p_out):
+    print(f"Running dac analog test with pin {p_in} as input and {p_out} as output\n")
+    pin_in = analogio.AnalogIn(p_in)
+    pin_out = analogio.AnalogOut(p_out)
+
+    for v in range(0, 65536, 4096):
+        pin_out.value = v
+        print(f"Value {v} read as {pin_in.value}")
+
+    pin_in.deinit()
+    pin_out.deinit()
+
+
+def test_dac_digital(p_in, p_out):
+    print(f"Running dac digital test with pin {p_in} as input and {p_out} as output")
+    pin_in = digitalio.DigitalInOut(p_in)
+    pin_out = analogio.AnalogOut(p_out)
+
+    for v in range(0, 65536, 4096):
+        pin_out.value = v
+        print(f"Value {v} read as {pin_in.value}")
+
+    pin_in.deinit()
+    pin_out.deinit()
+
+
+def test_dual(pair1, pair2):
+    # verifies that the DACs can be set independently
+    print(f"Running pair test\n")
+    pin1_in = analogio.AnalogIn(pair1[0])
+    pin1_out = analogio.AnalogOut(pair1[1])
+    pin2_in = analogio.AnalogIn(pair2[0])
+    pin2_out = analogio.AnalogOut(pair2[1])
+
+    for v in range(0, 65536, 4096):
+        v2 = 65535 - v
+        pin1_out.value = v
+        pin2_out.value = v2
+        print(f"Pair1: Value {v} read as {pin1_in.value}")
+        print(f"Pair2: Value {v2} read as {pin2_in.value}")
+
+    pin1_in.deinit()
+    pin1_out.deinit()
+    pin2_in.deinit()
+    pin2_out.deinit()
+
+
+def test_analog_hilo(p_in, p_out):
+    print(f"Running analog hilo test with pin {p_in} as input and {p_out} as output")
+    pin_in = analogio.AnalogIn(p_in)
+    pin_out = digitalio.DigitalInOut(p_out)
+    pin_out.switch_to_output()
+
+    for v in (False, True, False, True):
+        pin_out.value = v
+        print(f"Value {v} read as {pin_in.value}")
+
+    pin_in.deinit()
+    pin_out.deinit()
+
+
+def test_pair(pair):
+    # FIXME: test_analog_hilo works fine alone, but fails when the other dac functions are executed
+    test_analog_hilo(*pair)
+    test_dac_analog(*pair)
+    test_dac_digital(*pair)
+
+
+def main():
+    pair1 = (board.A3, board.DAC1)
+    pair2 = (board.A2, board.DAC2)
+    print("running DAC1 tests")
+    test_pair(pair1)
+    print("running DAC2 tests")
+    test_pair(pair2)
+    print("running dual DAC tests")
+    test_dual(pair1, pair2)
+
+
+main()
diff --git a/ports/stm/boards/cygnet/tests/board_voltage.py b/ports/stm/boards/cygnet/tests/board_voltage.py
new file mode 100644
index 0000000000000..2cb0ad4cc0f87
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/board_voltage.py
@@ -0,0 +1,146 @@
+# SPDX-FileCopyrightText: 2018 Shawn Hymel for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+
+print("pins test")
+
+"""
+`adafruit_boardtest.boardtest_gpio`
+====================================================
+Toggles all available GPIO on a board. Verify their operation with an LED,
+multimeter, another microcontroller, etc.
+
+Run this script as its own main.py to individually run the test, or compile
+with mpy-cross and call from separate test script.
+
+* Author(s): Shawn Hymel for Adafruit Industries
+
+Implementation Notes
+--------------------
+
+**Software and Dependencies:**
+
+* Adafruit CircuitPython firmware for the supported boards:
+  https://github.com/adafruit/circuitpython/releases
+
+"""
+
+import time
+
+import board
+import digitalio
+import supervisor
+
+__version__ = "0.0.0-auto.0"
+__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_BoardTest.git"
+
+# Constants
+LED_ON_DELAY_TIME = 0.2  # Seconds
+LED_OFF_DELAY_TIME = 0.2  # Seconds
+LED_PIN_NAMES = ["L", "LED", "RED_LED", "GREEN_LED", "BLUE_LED"]
+
+# Test result strings
+PASS = "PASS"
+FAIL = "FAIL"
+NA = "N/A"
+
+
+# Determine if given value is a number
+def _is_number(val):
+    try:
+        float(val)
+        return True
+    except ValueError:
+        return False
+
+
+# Release pins
+def _deinit_pins(gpios):
+    for g in gpios:
+        g.deinit()
+
+
+# Toggle IO pins while waiting for answer
+def _toggle_wait(pin_gpios):
+    timestamp = time.monotonic()
+    led_state = False
+    failed = []
+    for pg in pin_gpios:
+        (pin, gpio) = pg
+        print("Is pin %s toggling? [y/n]" % pin)
+        done = False
+        while not done:
+            if led_state:
+                if time.monotonic() > timestamp + LED_ON_DELAY_TIME:
+                    led_state = False
+                    timestamp = time.monotonic()
+            else:
+                if time.monotonic() > timestamp + LED_OFF_DELAY_TIME:
+                    led_state = True
+                    timestamp = time.monotonic()
+
+            gpio.value = led_state
+            if supervisor.runtime.serial_bytes_available:
+                answer = input()
+                if bool(answer == "y"):
+                    done = True
+                elif bool(answer == "n"):
+                    failed += pin
+                    done = True
+    return failed
+
+
+def buildPin(pin):
+    gpio = digitalio.DigitalInOut(pin)
+    return gpio
+
+
+def run_test(pins):
+    """
+    Toggles all available GPIO on and off repeatedly.
+
+    :param list[str] pins: list of pins to run the test on
+    :return: tuple(str, list[str]): test result followed by list of pins tested
+    """
+
+    # Create a list of analog GPIO pins
+    analog_pins = [p for p in pins if p[0] == "A" and _is_number(p[1])]
+
+    # Create a list of digital GPIO
+    digital_pins = [p for p in pins if p[0] == "D" and _is_number(p[1])]
+
+    # Toggle LEDs if we find any
+    gpio_pins = analog_pins + digital_pins
+
+    if gpio_pins:
+        # Print out the LEDs found
+        print("GPIO pins found:", end=" ")
+        for pin in gpio_pins:
+            print(pin, end=" ")
+        print("\n")
+
+        # Create a list of IO objects for us to toggle
+        gpios = [buildPin(getattr(board, p)) for p in gpio_pins]
+
+        print("built GPIOs")
+        # Set all IO to output
+        for gpio in gpios:
+            gpio.direction = digitalio.Direction.OUTPUT
+
+        # Toggle pins while waiting for user to verify LEDs blinking
+        result = _toggle_wait(zip(gpio_pins, gpios))
+
+        # Release pins
+        _deinit_pins(gpios)
+
+        if result:
+            return FAIL, gpio_pins
+
+        return PASS, gpio_pins
+
+    # Else (no pins found)
+    print("No GPIO pins found")
+    return NA, []
+
+
+run_test([p for p in dir(board)])
diff --git a/ports/stm/boards/cygnet/tests/button.py b/ports/stm/boards/cygnet/tests/button.py
new file mode 100644
index 0000000000000..4f00254ddb6dd
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/button.py
@@ -0,0 +1,22 @@
+import board
+import digitalio
+import time
+
+
+def monitor_button(pin, callback):
+    with digitalio.DigitalInOut(pin) as button:
+        newstate = not button.value  # state is inverted
+        state = not newstate  # ensure change reported to start with
+        while callback(newstate, newstate != state):
+            state = newstate
+            newstate = button.value
+            time.sleep(0.01)
+
+
+def print_changes(state, changed):
+    if changed:
+        print(f"button pressed {state}")
+    return True
+
+
+monitor_button(board.BUTTON_USR, print_changes)
diff --git a/ports/stm/boards/cygnet/tests/enable_3v3.py b/ports/stm/boards/cygnet/tests/enable_3v3.py
new file mode 100644
index 0000000000000..c32bbc58b80ec
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/enable_3v3.py
@@ -0,0 +1,35 @@
+# Background: I have a Swan R5 board running circuit python
+# And I import the "board" module
+import board
+import digitalio
+import supervisor
+import time
+
+# Scenario: Enable 3V3 pin definition
+# Then the symbol "board.ENABLE_3V3" is defined
+assert board.ENABLE_3V3 is not None
+
+# Scenario: Discharge 3V3 definition
+# Then the symbol "board.DISCHARGE_3V3" is defined
+assert board.DISCHARGE_3V3 is not None
+# And the symbol "board.DISABLE_DISCHARGING" is defined to be "True"
+assert board.DISABLE_DISCHARGING is not None and board.DISABLE_DISCHARGING == True
+# And the symbol "board.ENABLE_DISCHARGING" is defined to be "False"
+assert board.ENABLE_DISCHARGING is not None and board.ENABLE_DISCHARGING == False
+
+# Scenario: Toggle ENBLE_3V3
+# Given I have a LED connected between the 3V3 and GND pins
+# And ENABLE_3V3 is configured for output
+_3v3 = digitalio.DigitalInOut(board.ENABLE_3V3)
+_3v3.direction = digitalio.Direction.OUTPUT
+# When I run code to toggle the pin at 0.5Hz
+# Then I see the LED switch on and off at 0.5Hz
+print("Toggling 3V3. Press a key to stop.")
+
+while not supervisor.runtime.serial_bytes_available:
+    _3v3.value = True
+    time.sleep(1.0)
+    _3v3.value = False
+    time.sleep(1.0)
+
+print("Toggling stopped.")
diff --git a/ports/stm/boards/cygnet/tests/i2c_scan.py b/ports/stm/boards/cygnet/tests/i2c_scan.py
new file mode 100644
index 0000000000000..8e3ef557d136b
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/i2c_scan.py
@@ -0,0 +1,20 @@
+import board
+import busio
+
+i2c = busio.I2C(board.SCL, board.SDA)
+count = 0
+
+# Wait for I2C lock
+while not i2c.try_lock():
+    pass
+
+# Scan for devices on the I2C bus
+print("Scanning I2C bus")
+for x in i2c.scan():
+    print(hex(x))
+    count += 1
+
+print("%d device(s) found on I2C bus" % count)
+
+# Release the I2C bus
+i2c.unlock()
diff --git a/ports/stm/boards/cygnet/tests/pwnio.py b/ports/stm/boards/cygnet/tests/pwnio.py
new file mode 100644
index 0000000000000..71888d867b8e2
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/pwnio.py
@@ -0,0 +1,17 @@
+import time
+import pwmio
+
+
+def fade(pin):
+    led = pwmio.PWMOut(pin, frequency=5000, duty_cycle=0)
+    # LED setup for QT Py M0:
+    # led = pwmio.PWMOut(board.SCK, frequency=5000, duty_cycle=0)
+
+    while True:
+        for i in range(100):
+            # PWM LED up and down
+            if i < 50:
+                led.duty_cycle = int(i * 2 * 65535 / 100)  # Up
+            else:
+                led.duty_cycle = 65535 - int((i - 50) * 2 * 65535 / 100)  # Down
+            time.sleep(0.01)
diff --git a/ports/stm/boards/cygnet/tests/spi_bme680_smoke_test.py b/ports/stm/boards/cygnet/tests/spi_bme680_smoke_test.py
new file mode 100644
index 0000000000000..01e98bfd31b27
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/spi_bme680_smoke_test.py
@@ -0,0 +1,58 @@
+import board
+import busio
+import digitalio
+
+cs = digitalio.DigitalInOut(board.SS)
+cs.direction = digitalio.Direction.OUTPUT
+cs.value = True
+
+BME680_SPI_REGISTER = 0x73
+BME680_CHIPID_REGISTER = 0xD0
+BME680_CHIPID = 0x61
+SPI_HERZ = 0x500000
+
+spi = busio.SPI(board.SCK, MISO=board.MISO, MOSI=board.MOSI)
+
+
+def readByte(addr):
+    value = -1
+    while not spi.try_lock():
+        pass
+    try:
+        spi.configure(baudrate=500000, phase=0, polarity=0)
+
+        cs.value = False
+        result = bytearray(1)
+        result[0] = addr | 0x80
+        spi.write(result)
+        spi.readinto(result)
+        value = result[0]
+        return value
+    finally:
+        spi.unlock()
+        cs.value = True
+
+
+def writeByte(addr, value):
+    while not spi.try_lock():
+        pass
+    try:
+        spi.configure(baudrate=500000, phase=0, polarity=0)
+
+        cs.value = False
+        result = bytearray(2)
+        result[0] = addr & ~0x80
+        result[1] = value
+        spi.write(result)
+    finally:
+        spi.unlock()
+
+
+# put the device in the correct mode to read the ID
+reg = readByte(BME680_SPI_REGISTER)
+if (reg & 16) != 0:
+    writeByte(BME680_SPI_REGISTER, reg & ~16)
+
+id = readByte(BME680_CHIPID_REGISTER)
+
+print(f"id is {id}, expected {BME680_CHIPID}")
diff --git a/ports/stm/boards/cygnet/tests/uart.py b/ports/stm/boards/cygnet/tests/uart.py
new file mode 100644
index 0000000000000..a8dbc272a8998
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/uart.py
@@ -0,0 +1,37 @@
+import board
+import busio
+import digitalio
+import usb_cdc
+import time
+
+while not usb_cdc.console.in_waiting:
+    time.sleep(0.1)
+
+print("USART test")
+
+# For most CircuitPython boards:
+led = digitalio.DigitalInOut(board.LED)
+# For QT Py M0:
+# led = digitalio.DigitalInOut(board.SCK)
+led.direction = digitalio.Direction.OUTPUT
+
+uart = busio.UART(board.TX, board.RX, baudrate=9600)
+
+while True:
+    data = uart.read(32)  # read up to 32 bytes
+    # print(data)  # this is a bytearray type
+
+    if data is not None:
+        led.value = True
+
+        # convert bytearray to string
+        data_string = "*".join([chr(b) for b in data])
+        print(data_string, end="")
+
+        led.value = False
+
+    if usb_cdc.console.in_waiting:
+        data = usb_cdc.console.read()
+        data_string = "*".join([chr(b) for b in data])
+        print("writing " + data_string)
+        uart.write(data)
diff --git a/ports/stm/boards/cygnet/tests/urandom.py b/ports/stm/boards/cygnet/tests/urandom.py
new file mode 100644
index 0000000000000..25ff655596b1d
--- /dev/null
+++ b/ports/stm/boards/cygnet/tests/urandom.py
@@ -0,0 +1,10 @@
+import os
+
+
+def main():
+    print("Random number test")
+    r = os.urandom(32)
+    print(f"urandom TRNG string is {r}")
+
+
+main()
diff --git a/ports/stm/common-hal/microcontroller/Pin.c b/ports/stm/common-hal/microcontroller/Pin.c
index e0ff3f138dfc2..8a6f57f9ab63d 100644
--- a/ports/stm/common-hal/microcontroller/Pin.c
+++ b/ports/stm/common-hal/microcontroller/Pin.c
@@ -11,6 +11,8 @@
 
 #if defined(TFBGA216)
 GPIO_TypeDef *ports[] = {GPIOA, GPIOB, GPIOC, GPIOD, GPIOE, GPIOF, GPIOG, GPIOH, GPIOI, GPIOJ, GPIOK};
+#elif defined(LQFP48)
+GPIO_TypeDef *ports[] = {GPIOA, GPIOB, GPIOC};
 #elif defined(LQFP144) || defined(WLCSP144)
 GPIO_TypeDef *ports[] = {GPIOA, GPIOB, GPIOC, GPIOD, GPIOE, GPIOF, GPIOG};
 #elif defined(LQFP100_f4) || (LQFP100_x7)
diff --git a/ports/stm/mpconfigport.mk b/ports/stm/mpconfigport.mk
index 3266212962738..c119596588d8d 100644
--- a/ports/stm/mpconfigport.mk
+++ b/ports/stm/mpconfigport.mk
@@ -80,11 +80,18 @@ ifeq ($(MCU_SERIES),L4)
         CIRCUITPY_NVM ?= 0
         CIRCUITPY_ROTARYIO ?= 0
         CIRCUITPY_RTC ?= 1
+        UF2_FAMILY_ID ?= 0x00ff6919
+endif
+
+ifeq ($(MCU_VARIANT),STM32L4R5xx)
         # todo - this varies between devices in the series
         # This slide deck https://www.st.com/content/ccc/resource/training/technical/product_training/98/89/c8/6c/3e/e9/49/79/STM32L4_Peripheral_USB.pdf/files/STM32L4_Peripheral_USB.pdf/jcr:content/translations/en.STM32L4_Peripheral_USB.pdf
         # cites 16 endpoints, 8 endpoint pairs, while section 3.39 of the L4R5 datasheet states 6 endpoint pairs.
         USB_NUM_ENDPOINT_PAIRS = 6
-        UF2_FAMILY_ID ?= 0x00ff6919
+endif
+
+ifeq ($(MCU_VARIANT),STM32L433xx)
+        USB_NUM_ENDPOINT_PAIRS = 4
 endif
 
 CIRCUITPY_PARALLELDISPLAYBUS := 0
diff --git a/ports/stm/packages/LQFP48.c b/ports/stm/packages/LQFP48.c
new file mode 100644
index 0000000000000..46b737adeb8e3
--- /dev/null
+++ b/ports/stm/packages/LQFP48.c
@@ -0,0 +1,63 @@
+#include "shared-bindings/microcontroller/__init__.h"
+#include "common-hal/microcontroller/Pin.h"
+#include "py/obj.h"
+
+static const mp_rom_map_elem_t mcu_pin_globals_table[] = {
+// Pins 1-12
+    /* VBAT -------------------------------------------*/
+    { MP_ROM_QSTR(MP_QSTR_PC13), MP_ROM_PTR(&pin_PC13) },
+    // PC14 OSC32_IN ----------------------------------*/
+    // PC15 OSC32_OUT ---------------------------------*/
+    // { MP_ROM_QSTR(MP_QSTR_PH00), MP_ROM_PTR(&pin_PH00) }, PH00 OSC_IN
+    // { MP_ROM_QSTR(MP_QSTR_PH01), MP_ROM_PTR(&pin_PH01) }, PH01 OSC_OUT
+    // NRST -------------------------------------------*/
+    // VSSA -------------------------------------------*/
+    // VDDA -------------------------------------------*/
+    { MP_ROM_QSTR(MP_QSTR_PA00), MP_ROM_PTR(&pin_PA00) },
+    { MP_ROM_QSTR(MP_QSTR_PA01), MP_ROM_PTR(&pin_PA01) },
+    { MP_ROM_QSTR(MP_QSTR_PA02), MP_ROM_PTR(&pin_PA02) },
+
+// Pins 13-24
+    { MP_ROM_QSTR(MP_QSTR_PA03), MP_ROM_PTR(&pin_PA03) },
+    { MP_ROM_QSTR(MP_QSTR_PA04), MP_ROM_PTR(&pin_PA04) },
+    { MP_ROM_QSTR(MP_QSTR_PA05), MP_ROM_PTR(&pin_PA05) },
+    { MP_ROM_QSTR(MP_QSTR_PA06), MP_ROM_PTR(&pin_PA06) },
+    { MP_ROM_QSTR(MP_QSTR_PA07), MP_ROM_PTR(&pin_PA07) },
+    { MP_ROM_QSTR(MP_QSTR_PB00), MP_ROM_PTR(&pin_PB00) },
+    { MP_ROM_QSTR(MP_QSTR_PB01), MP_ROM_PTR(&pin_PB01) },
+    { MP_ROM_QSTR(MP_QSTR_PB02), MP_ROM_PTR(&pin_PB02) },
+    { MP_ROM_QSTR(MP_QSTR_PB10), MP_ROM_PTR(&pin_PB10) },
+    { MP_ROM_QSTR(MP_QSTR_PB11), MP_ROM_PTR(&pin_PB11) },
+    // VSS --------------------------------------------*/
+    // VDD --------------------------------------------*/
+
+// Pins 25-36
+    { MP_ROM_QSTR(MP_QSTR_PB12), MP_ROM_PTR(&pin_PB12) },
+    { MP_ROM_QSTR(MP_QSTR_PB13), MP_ROM_PTR(&pin_PB13) },
+    { MP_ROM_QSTR(MP_QSTR_PB14), MP_ROM_PTR(&pin_PB14) },
+    { MP_ROM_QSTR(MP_QSTR_PB15), MP_ROM_PTR(&pin_PB15) },
+    { MP_ROM_QSTR(MP_QSTR_PA08), MP_ROM_PTR(&pin_PA08) },
+    { MP_ROM_QSTR(MP_QSTR_PA09), MP_ROM_PTR(&pin_PA09) },
+    { MP_ROM_QSTR(MP_QSTR_PA10), MP_ROM_PTR(&pin_PA10) },
+    { MP_ROM_QSTR(MP_QSTR_PA11), MP_ROM_PTR(&pin_PA11) },
+    { MP_ROM_QSTR(MP_QSTR_PA12), MP_ROM_PTR(&pin_PA12) },
+    { MP_ROM_QSTR(MP_QSTR_PA13), MP_ROM_PTR(&pin_PA13) },
+    // VSS --------------------------------------------*/
+    // VDD --------------------------------------------*/
+
+// Pins 37-48
+    { MP_ROM_QSTR(MP_QSTR_PA14), MP_ROM_PTR(&pin_PA14) },
+    { MP_ROM_QSTR(MP_QSTR_PA15), MP_ROM_PTR(&pin_PA15) },
+    { MP_ROM_QSTR(MP_QSTR_PB03), MP_ROM_PTR(&pin_PB03) },
+    { MP_ROM_QSTR(MP_QSTR_PB04), MP_ROM_PTR(&pin_PB04) },
+    { MP_ROM_QSTR(MP_QSTR_PB05), MP_ROM_PTR(&pin_PB05) },
+    { MP_ROM_QSTR(MP_QSTR_PB06), MP_ROM_PTR(&pin_PB06) },
+    { MP_ROM_QSTR(MP_QSTR_PB07), MP_ROM_PTR(&pin_PB07) },
+    // BOOT0 ------------------------------------------*/
+    { MP_ROM_QSTR(MP_QSTR_PB08), MP_ROM_PTR(&pin_PB08) },
+    { MP_ROM_QSTR(MP_QSTR_PB09), MP_ROM_PTR(&pin_PB09) },
+    // VSS --------------------------------------------*/
+    // VDD --------------------------------------------*/
+
+};
+MP_DEFINE_CONST_DICT(mcu_pin_globals, mcu_pin_globals_table);
diff --git a/ports/stm/peripherals/periph.h b/ports/stm/peripherals/periph.h
index 438db7938672e..4960125d90f12 100644
--- a/ports/stm/peripherals/periph.h
+++ b/ports/stm/peripherals/periph.h
@@ -21,11 +21,11 @@ typedef struct {
 } mcu_periph_obj_t;
 
 #define PERIPH(index, alt, p_pin)       \
-    { \
-        .periph_index = index, \
-        .altfn_index = alt, \
-        .pin = p_pin, \
-    }
+        { \
+            .periph_index = index, \
+            .altfn_index = alt, \
+            .pin = p_pin, \
+        }
 
 // Timer Peripheral
 
@@ -37,12 +37,12 @@ typedef struct {
 } mcu_tim_pin_obj_t;
 
 #define TIM(index, alt, channel, tim_pin)       \
-    { \
-        .tim_index = index - 1, \
-        .altfn_index = alt, \
-        .channel_index = channel - 1, \
-        .pin = tim_pin, \
-    }
+        { \
+            .tim_index = index - 1, \
+            .altfn_index = alt, \
+            .channel_index = channel - 1, \
+            .pin = tim_pin, \
+        }
 
 // F4 Series
 // Access Lines
@@ -84,6 +84,13 @@ typedef struct {
 #include "stm32l4/stm32l4r5xx/periph.h"
 #endif
 
+#ifdef STM32L433xx
+#define HAS_DAC 1
+#define HAS_TRNG 1
+#define HAS_BASIC_TIM 1
+#include "stm32l4/stm32l433xx/periph.h"
+#endif
+
 #ifdef STM32F405xx
 #define HAS_DAC 1
 #define HAS_TRNG 1
diff --git a/ports/stm/peripherals/pins.h b/ports/stm/peripherals/pins.h
index 999f8172d9713..c91879939552e 100644
--- a/ports/stm/peripherals/pins.h
+++ b/ports/stm/peripherals/pins.h
@@ -32,24 +32,24 @@ typedef struct {
 // but all 3 ADCs will share the same input number per pin.
 // F4 family has 3 ADC max, 24 channels max.
 #define ADC_INPUT(mask, number) \
-    .adc_unit = mask, \
-    .adc_channel = number,
+        .adc_unit = mask, \
+        .adc_channel = number,
 
 #define NO_ADC \
-    .adc_unit = 0x00, \
-    .adc_channel = 0x1f
+        .adc_unit = 0x00, \
+        .adc_channel = 0x1f
 
 extern const mp_obj_type_t mcu_pin_type;
 
 // STM32 can have up to 9 ports, each restricted to 16 pins
 // We split the pin/port evenly, in contrast to nrf.
 #define PIN(p_port, p_number, p_adc)       \
-    { \
-        { &mcu_pin_type }, \
-        .port = p_port, \
-        .number = p_number, \
-        p_adc \
-    }
+        { \
+            { &mcu_pin_type }, \
+            .port = p_port, \
+            .number = p_number, \
+            p_adc \
+        }
 
 // Use illegal pin value to mark unassigned pins.
 #define NO_PIN 0xff
@@ -70,6 +70,9 @@ extern const mp_obj_type_t mcu_pin_type;
 #ifdef STM32L4R5xx
 #include "stm32l4/stm32l4r5xx/pins.h"
 #endif
+#ifdef STM32L433xx
+#include "stm32l4/stm32l433xx/pins.h"
+#endif
 #ifdef STM32F405xx
 #include "stm32f4/stm32f405xx/pins.h"
 #endif
diff --git a/ports/stm/peripherals/stm32l4/clocks.c b/ports/stm/peripherals/stm32l4/clocks.c
index a005c2bf7908f..d4cf3312efe14 100644
--- a/ports/stm/peripherals/stm32l4/clocks.c
+++ b/ports/stm/peripherals/stm32l4/clocks.c
@@ -11,6 +11,8 @@
 // L4 Series
 #ifdef STM32L4R5xx
 #include "stm32l4/stm32l4r5xx/clocks.h"
+#elif STM32L433xx
+#include "stm32l4/stm32l433xx/clocks.h"
 #else
 #error Please add other MCUs here so that they are not silently ignored due to #define typos
 #endif
@@ -44,49 +46,82 @@ void stm32_peripherals_clocks_init(void) {
 
     /** Configure the main internal regulator output voltage
   */
+    #if STM32L4R5xx
     if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1_BOOST) != HAL_OK) {
         Error_Handler();
     }
-
+    #elif STM32L433xx
+    if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK) {
+        Error_Handler();
+    }
+    #endif
 
     /* Activate PLL with MSI , stabilizied via PLL by LSE */
+    #ifdef STM32L4R5xx
     RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE | RCC_OSCILLATORTYPE_MSI;
     RCC_OscInitStruct.MSIState = RCC_MSI_ON;
     RCC_OscInitStruct.LSEState = RCC_LSE_ON;
-    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_11;
     RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
     RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
     RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
+    RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
+    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_11;
     RCC_OscInitStruct.PLL.PLLM = 6;
     RCC_OscInitStruct.PLL.PLLN = 30;
     RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV5;
     RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
+    #elif STM32L433xx
+    RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSE | RCC_OSCILLATORTYPE_HSI48 | RCC_OSCILLATORTYPE_MSI;
+    RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
+    RCC_OscInitStruct.MSIState = RCC_MSI_ON;
+    RCC_OscInitStruct.LSEState = RCC_LSE_ON;
+    RCC_OscInitStruct.MSICalibrationValue = 0;
+    RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
+    RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
+    RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
+    RCC_OscInitStruct.PLL.PLLM = 1;
+    RCC_OscInitStruct.PLL.PLLN = 40;
+    RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7;
+    RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
     RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
+    #endif
+
     HAL_CHECK(HAL_RCC_OscConfig(&RCC_OscInitStruct));
 
+    #ifdef STM32L4R5xx
     /* Enable MSI Auto-calibration through LSE */
     HAL_RCCEx_EnableMSIPLLMode();
+    #endif
 
     /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2
     clocks dividers */
     RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
     RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
-    // Avoid overshoot and start with HCLK 60 MHz
     RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
     RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
     RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
+    #ifdef STM32L4R5xx
     HAL_CHECK(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3));
+    #elif STM32L433xx
+    HAL_CHECK(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4));
+    #endif
 
     /* AHB prescaler divider at 1 as second step */
+    #ifdef STM32L4R5xx
     RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK;
     RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
     HAL_CHECK(HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5));
+    #endif
 
     /* Select MSI output as USB clock source */
     PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB | RCC_PERIPHCLK_RTC | RCC_PERIPHCLK_ADC;
+    #ifdef STM32L4R5xx
     PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_MSI;
+    #elif STM32L433xx
+    PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
+    #endif
     PeriphClkInitStruct.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;
     PeriphClkInitStruct.AdcClockSelection = RCC_ADCCLKSOURCE_SYSCLK;
-    HAL_CHECK(HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct));
 
+    HAL_CHECK(HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct));
 }
diff --git a/ports/stm/peripherals/stm32l4/stm32l433xx/clocks.h b/ports/stm/peripherals/stm32l4/stm32l433xx/clocks.h
new file mode 100644
index 0000000000000..a01cae704d6b6
--- /dev/null
+++ b/ports/stm/peripherals/stm32l4/stm32l433xx/clocks.h
@@ -0,0 +1,49 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 Blues Wireless Contributors
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "stm32l4xx_hal.h"
+
+// Chip:                STM32L433
+// Line Type:           Foundation Line
+// Speed:               80MHz (MAX)
+
+// Defaults:
+#ifndef CPY_CLK_VSCALE
+#define CPY_CLK_VSCALE (PWR_REGULATOR_VOLTAGE_SCALE1)      // up to 80MHz
+#endif
+#ifndef CPY_CLK_PLLM
+#define CPY_CLK_PLLM (1)
+#endif
+#ifndef CPY_CLK_PLLN
+#define CPY_CLK_PLLN (40)
+#endif
+#ifndef CPY_CLK_PLLP
+#define CPY_CLK_PLLP (RCC_PLLP_DIV7)
+#endif
+#ifndef CPY_CLK_PLLQ
+#define CPY_CLK_PLLQ (2)
+#endif
+#ifndef CPY_CLK_AHBDIV
+#define CPY_CLK_AHBDIV (RCC_SYSCLK_DIV1)
+#endif
+#ifndef CPY_CLK_APB1DIV
+#define CPY_CLK_APB1DIV (RCC_HCLK_DIV1)
+#endif
+#ifndef CPY_CLK_APB2DIV
+#define CPY_CLK_APB2DIV (RCC_HCLK_DIV1)
+#endif
+#ifndef CPY_CLK_FLASH_LATENCY
+#define CPY_CLK_FLASH_LATENCY (FLASH_LATENCY_4)
+#endif
+#ifndef CPY_CLK_USB_USES_AUDIOPLL
+#define CPY_CLK_USB_USES_AUDIOPLL (0)
+#endif
+
+#ifndef BOARD_HAS_HIGH_SPEED_CRYSTAL
+#define BOARD_HAS_HIGH_SPEED_CRYSTAL (1)
+#endif
diff --git a/ports/stm/peripherals/stm32l4/stm32l433xx/gpio.c b/ports/stm/peripherals/stm32l4/stm32l433xx/gpio.c
new file mode 100644
index 0000000000000..eb8914b5585c1
--- /dev/null
+++ b/ports/stm/peripherals/stm32l4/stm32l433xx/gpio.c
@@ -0,0 +1,26 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 Blues Wireless Contributors
+//
+// SPDX-License-Identifier: MIT
+
+#include "peripherals/gpio.h"
+#include "common-hal/microcontroller/Pin.h"
+
+void stm32_peripherals_gpio_init(void) {
+    // Enable all GPIO for now
+    __HAL_RCC_GPIOA_CLK_ENABLE();
+    __HAL_RCC_GPIOB_CLK_ENABLE();
+    __HAL_RCC_GPIOC_CLK_ENABLE();
+    __HAL_RCC_GPIOH_CLK_ENABLE();
+
+    // Never reset pins
+    never_reset_pin_number(2, 14); // PC14 OSC32_IN
+    never_reset_pin_number(2, 15); // PC15 OSC32_OUT
+    never_reset_pin_number(0, 13); // PA13 SWDIO
+    never_reset_pin_number(0, 14); // PA14 SWCLK
+}
+
+void stm32l4_peripherals_status_led(uint8_t led, uint8_t state) {
+
+}
diff --git a/ports/stm/peripherals/stm32l4/stm32l433xx/periph.c b/ports/stm/peripherals/stm32l4/stm32l433xx/periph.c
new file mode 100644
index 0000000000000..e98c192c68517
--- /dev/null
+++ b/ports/stm/peripherals/stm32l4/stm32l433xx/periph.c
@@ -0,0 +1,91 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 Blues Wireless Contributors
+//
+// SPDX-License-Identifier: MIT
+
+#include "py/obj.h"
+#include "py/mphal.h"
+#include "peripherals/pins.h"
+#include "peripherals/periph.h"
+
+I2C_TypeDef *mcu_i2c_banks[I2C_BANK_ARRAY_LEN] = {I2C1, I2C2};
+
+const mcu_periph_obj_t mcu_i2c_sda_list[I2C_SDA_ARRAY_LEN] = {
+    PERIPH(1, 4, &pin_PA10),
+    PERIPH(2, 4, &pin_PB14),
+};
+
+const mcu_periph_obj_t mcu_i2c_scl_list[I2C_SCL_ARRAY_LEN] = {
+    PERIPH(1, 4, &pin_PA09),
+    PERIPH(2, 4, &pin_PB13),
+};
+
+SPI_TypeDef *mcu_spi_banks[SPI_BANK_ARRAY_LEN] = {SPI1};
+
+const mcu_periph_obj_t mcu_spi_sck_list[SPI_SCK_ARRAY_LEN] = {
+    PERIPH(1, 5, &pin_PB03),
+};
+const mcu_periph_obj_t mcu_spi_mosi_list[SPI_MOSI_ARRAY_LEN] = {
+    PERIPH(1, 5, &pin_PA12),
+};
+const mcu_periph_obj_t mcu_spi_miso_list[SPI_MISO_ARRAY_LEN] = {
+    PERIPH(1, 5, &pin_PA11),
+};
+const mcu_periph_obj_t mcu_spi_nss_list[SPI_NSS_ARRAY_LEN] = {
+    PERIPH(1, 5, &pin_PA15),
+};
+
+USART_TypeDef *mcu_uart_banks[MAX_UART] = {USART1, USART2, USART3};
+bool mcu_uart_has_usart[MAX_UART] = {true, true, true, false, false};
+
+const mcu_periph_obj_t mcu_uart_tx_list[UART_TX_ARRAY_LEN] = {
+    PERIPH(2, 7, &pin_PA02),
+    PERIPH(1, 7, &pin_PA09),
+    PERIPH(1, 7, &pin_PB06),
+    PERIPH(3, 7, &pin_PB10),
+};
+const mcu_periph_obj_t mcu_uart_rx_list[UART_RX_ARRAY_LEN] = {
+    PERIPH(2, 7, &pin_PA03),
+    PERIPH(1, 7, &pin_PA10),
+    PERIPH(2, 7, &pin_PA15),
+    PERIPH(1, 7, &pin_PB07),
+    PERIPH(3, 7, &pin_PB11),
+};
+
+// Timers
+TIM_TypeDef *mcu_tim_banks[TIM_BANK_ARRAY_LEN] = {TIM1, TIM2, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, TIM15, TIM16, NULL};
+
+const mcu_tim_pin_obj_t mcu_tim_pin_list[TIM_PIN_ARRAY_LEN] = {
+    TIM(2, 1, 1, &pin_PA00),
+    TIM(2, 1, 2, &pin_PA01),
+    TIM(2, 1, 3, &pin_PA02),
+    TIM(15, 15, 1, &pin_PA02),
+    TIM(2, 1, 4, &pin_PA03),
+    TIM(15, 15, 2, &pin_PA03),
+    TIM(2, 1, 1, &pin_PA05),
+    TIM(16, 15, 1, &pin_PA06),
+    TIM(1, 1, 1, &pin_PA08),
+    TIM(1, 1, 2, &pin_PA09),
+    TIM(1, 1, 3, &pin_PA10),
+    TIM(1, 1, 4, &pin_PA11),
+    TIM(2, 1, 1, &pin_PA15),
+    TIM(2, 1, 2, &pin_PB03),
+    TIM(16, 15, 1, &pin_PB08),
+    TIM(2, 1, 3, &pin_PB10),
+    TIM(2, 1, 4, &pin_PB11),
+    TIM(15, 15, 1, &pin_PB14),
+    TIM(15, 15, 2, &pin_PB15),
+};
+
+// CAN
+CAN_TypeDef *mcu_can_banks[] = {CAN1};
+
+const mcu_periph_obj_t mcu_can_tx_list[2] = {
+    PERIPH(1, 10, &pin_PA12),
+    PERIPH(1, 10, &pin_PB09),
+};
+const mcu_periph_obj_t mcu_can_rx_list[2] = {
+    PERIPH(1, 10, &pin_PA11),
+    PERIPH(1, 10, &pin_PB08),
+};
diff --git a/ports/stm/peripherals/stm32l4/stm32l433xx/periph.h b/ports/stm/peripherals/stm32l4/stm32l433xx/periph.h
new file mode 100644
index 0000000000000..6bf0add01fef4
--- /dev/null
+++ b/ports/stm/peripherals/stm32l4/stm32l433xx/periph.h
@@ -0,0 +1,46 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 Blues Wireless Contributors
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+// I2C
+#define I2C_BANK_ARRAY_LEN 2
+#define I2C_SDA_ARRAY_LEN 2
+#define I2C_SCL_ARRAY_LEN 2
+extern I2C_TypeDef *mcu_i2c_banks[I2C_BANK_ARRAY_LEN];
+extern const mcu_periph_obj_t mcu_i2c_sda_list[I2C_SDA_ARRAY_LEN];
+extern const mcu_periph_obj_t mcu_i2c_scl_list[I2C_SCL_ARRAY_LEN];
+
+// SPI
+#define SPI_BANK_ARRAY_LEN 1
+#define SPI_SCK_ARRAY_LEN 1
+#define SPI_MOSI_ARRAY_LEN 1
+#define SPI_MISO_ARRAY_LEN 1
+#define SPI_NSS_ARRAY_LEN 1
+extern SPI_TypeDef *mcu_spi_banks[SPI_BANK_ARRAY_LEN];
+extern const mcu_periph_obj_t mcu_spi_sck_list[SPI_SCK_ARRAY_LEN];
+extern const mcu_periph_obj_t mcu_spi_mosi_list[SPI_MOSI_ARRAY_LEN];
+extern const mcu_periph_obj_t mcu_spi_miso_list[SPI_MISO_ARRAY_LEN];
+extern const mcu_periph_obj_t mcu_spi_nss_list[SPI_NSS_ARRAY_LEN];
+
+// UART
+#define UART_TX_ARRAY_LEN 4
+#define UART_RX_ARRAY_LEN 5
+extern USART_TypeDef *mcu_uart_banks[MAX_UART];
+extern bool mcu_uart_has_usart[MAX_UART];
+extern const mcu_periph_obj_t mcu_uart_tx_list[UART_TX_ARRAY_LEN];
+extern const mcu_periph_obj_t mcu_uart_rx_list[UART_RX_ARRAY_LEN];
+
+// Timers
+#define TIM_BANK_ARRAY_LEN 17
+#define TIM_PIN_ARRAY_LEN 19
+extern TIM_TypeDef *mcu_tim_banks[TIM_BANK_ARRAY_LEN];
+extern const mcu_tim_pin_obj_t mcu_tim_pin_list[TIM_PIN_ARRAY_LEN];
+
+// CAN
+extern CAN_TypeDef *mcu_can_banks[1];
+extern const mcu_periph_obj_t mcu_can_tx_list[2];
+extern const mcu_periph_obj_t mcu_can_rx_list[2];
diff --git a/ports/stm/peripherals/stm32l4/stm32l433xx/pins.c b/ports/stm/peripherals/stm32l4/stm32l433xx/pins.c
new file mode 100644
index 0000000000000..060f53031bb44
--- /dev/null
+++ b/ports/stm/peripherals/stm32l4/stm32l433xx/pins.c
@@ -0,0 +1,50 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 Blues Wireless Contributors
+//
+// SPDX-License-Identifier: MIT
+
+#include "py/obj.h"
+#include "py/mphal.h"
+#include "peripherals/pins.h"
+
+#include STM32_HAL_H
+
+const mcu_pin_obj_t pin_PA00 = PIN(0, 0, ADC_INPUT(ADC_1, 5));
+const mcu_pin_obj_t pin_PA01 = PIN(0, 1, ADC_INPUT(ADC_1, 6));
+const mcu_pin_obj_t pin_PA02 = PIN(0, 2, ADC_INPUT(ADC_1, 7));
+const mcu_pin_obj_t pin_PA03 = PIN(0, 3, ADC_INPUT(ADC_1, 8));
+const mcu_pin_obj_t pin_PA04 = PIN(0, 4, ADC_INPUT(ADC_1, 9));
+const mcu_pin_obj_t pin_PA05 = PIN(0, 5, ADC_INPUT(ADC_1, 10));
+const mcu_pin_obj_t pin_PA06 = PIN(0, 6, ADC_INPUT(ADC_1, 11));
+const mcu_pin_obj_t pin_PA07 = PIN(0, 7, ADC_INPUT(ADC_1, 12));
+const mcu_pin_obj_t pin_PA08 = PIN(0, 8, NO_ADC);
+const mcu_pin_obj_t pin_PA09 = PIN(0, 9, NO_ADC);
+const mcu_pin_obj_t pin_PA10 = PIN(0, 10, NO_ADC);
+const mcu_pin_obj_t pin_PA11 = PIN(0, 11, NO_ADC);
+const mcu_pin_obj_t pin_PA12 = PIN(0, 12, NO_ADC);
+const mcu_pin_obj_t pin_PA13 = PIN(0, 13, NO_ADC);
+const mcu_pin_obj_t pin_PA14 = PIN(0, 14, NO_ADC);
+const mcu_pin_obj_t pin_PA15 = PIN(0, 15, NO_ADC);
+const mcu_pin_obj_t pin_PB00 = PIN(1, 0, ADC_INPUT(ADC_1, 15));
+const mcu_pin_obj_t pin_PB01 = PIN(1, 1, ADC_INPUT(ADC_1, 16));
+const mcu_pin_obj_t pin_PB02 = PIN(1, 2, NO_ADC);
+const mcu_pin_obj_t pin_PB03 = PIN(1, 3, NO_ADC);
+const mcu_pin_obj_t pin_PB04 = PIN(1, 4, NO_ADC);
+const mcu_pin_obj_t pin_PB05 = PIN(1, 5, NO_ADC);
+const mcu_pin_obj_t pin_PB06 = PIN(1, 6, NO_ADC);
+const mcu_pin_obj_t pin_PB07 = PIN(1, 7, NO_ADC);
+const mcu_pin_obj_t pin_PB08 = PIN(1, 8, NO_ADC);
+const mcu_pin_obj_t pin_PB09 = PIN(1, 9, NO_ADC);
+const mcu_pin_obj_t pin_PB10 = PIN(1, 10, NO_ADC);
+const mcu_pin_obj_t pin_PB11 = PIN(1, 11, NO_ADC);
+const mcu_pin_obj_t pin_PB12 = PIN(1, 12, NO_ADC);
+const mcu_pin_obj_t pin_PB13 = PIN(1, 13, NO_ADC);
+const mcu_pin_obj_t pin_PB14 = PIN(1, 14, NO_ADC);
+const mcu_pin_obj_t pin_PB15 = PIN(1, 15, NO_ADC);
+const mcu_pin_obj_t pin_PC13 = PIN(2, 13, NO_ADC);
+const mcu_pin_obj_t pin_PC14 = PIN(2, 14, NO_ADC);
+const mcu_pin_obj_t pin_PC15 = PIN(2, 15, NO_ADC);
+const mcu_pin_obj_t pin_PH00 = PIN(5, 0, NO_ADC);
+const mcu_pin_obj_t pin_PH01 = PIN(5, 1, NO_ADC);
+const mcu_pin_obj_t pin_PH03 = PIN(5, 3, NO_ADC);
diff --git a/ports/stm/peripherals/stm32l4/stm32l433xx/pins.h b/ports/stm/peripherals/stm32l4/stm32l433xx/pins.h
new file mode 100644
index 0000000000000..93a175ddbad81
--- /dev/null
+++ b/ports/stm/peripherals/stm32l4/stm32l433xx/pins.h
@@ -0,0 +1,46 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2021 Blues Wireless Contributors
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+extern const mcu_pin_obj_t pin_PA00;
+extern const mcu_pin_obj_t pin_PA01;
+extern const mcu_pin_obj_t pin_PA02;
+extern const mcu_pin_obj_t pin_PA03;
+extern const mcu_pin_obj_t pin_PA04;
+extern const mcu_pin_obj_t pin_PA05;
+extern const mcu_pin_obj_t pin_PA06;
+extern const mcu_pin_obj_t pin_PA07;
+extern const mcu_pin_obj_t pin_PA08;
+extern const mcu_pin_obj_t pin_PA09;
+extern const mcu_pin_obj_t pin_PA10;
+extern const mcu_pin_obj_t pin_PA11;
+extern const mcu_pin_obj_t pin_PA12;
+extern const mcu_pin_obj_t pin_PA13;
+extern const mcu_pin_obj_t pin_PA14;
+extern const mcu_pin_obj_t pin_PA15;
+extern const mcu_pin_obj_t pin_PB00;
+extern const mcu_pin_obj_t pin_PB01;
+extern const mcu_pin_obj_t pin_PB02;
+extern const mcu_pin_obj_t pin_PB03;
+extern const mcu_pin_obj_t pin_PB04;
+extern const mcu_pin_obj_t pin_PB05;
+extern const mcu_pin_obj_t pin_PB06;
+extern const mcu_pin_obj_t pin_PB07;
+extern const mcu_pin_obj_t pin_PB08;
+extern const mcu_pin_obj_t pin_PB09;
+extern const mcu_pin_obj_t pin_PB10;
+extern const mcu_pin_obj_t pin_PB11;
+extern const mcu_pin_obj_t pin_PB12;
+extern const mcu_pin_obj_t pin_PB13;
+extern const mcu_pin_obj_t pin_PB14;
+extern const mcu_pin_obj_t pin_PB15;
+extern const mcu_pin_obj_t pin_PC13;
+extern const mcu_pin_obj_t pin_PC14;
+extern const mcu_pin_obj_t pin_PC15;
+extern const mcu_pin_obj_t pin_PH00;
+extern const mcu_pin_obj_t pin_PH01;
+extern const mcu_pin_obj_t pin_PH03;
diff --git a/ports/stm/supervisor/internal_flash.c b/ports/stm/supervisor/internal_flash.c
index 273af300a80b3..f6d687f08fd39 100644
--- a/ports/stm/supervisor/internal_flash.c
+++ b/ports/stm/supervisor/internal_flash.c
@@ -69,12 +69,18 @@ static const flash_layout_t flash_layout[] = {
 };
 static uint8_t _flash_cache[0x20000] __attribute__((aligned(4)));
 
-#elif defined(STM32L4)
+#elif defined(STM32L4R5XX)
 static const flash_layout_t flash_layout[] = {
     { 0x08100000, 0x1000, 256 },
 };
 static uint8_t _flash_cache[0x1000] __attribute__((aligned(4)));
 
+#elif defined(STM32L433XX)
+static const flash_layout_t flash_layout[] = {
+    { 0x08000000, 0x0800, 128 },
+};
+static uint8_t _flash_cache[0x0800] __attribute__((aligned(4)));
+
 #else
     #error Unsupported processor
 #endif
@@ -175,8 +181,13 @@ void port_internal_flash_flush(void) {
     // set up for erase
     FLASH_EraseInitTypeDef EraseInitStruct = {};
     #if CPY_STM32L4
+    #if defined(STM32L4R5XX)
     EraseInitStruct.TypeErase = TYPEERASE_PAGES;
-    EraseInitStruct.Banks = FLASH_BANK_2;       // filesystem stored in upper 1MB of flash in dual bank mode
+    EraseInitStruct.Banks = FLASH_BANK_2;           // filesystem stored in upper 1MB of flash in dual bank mode
+    #elif defined(STM32L433XX)
+    EraseInitStruct.TypeErase = TYPEERASE_PAGES;
+    EraseInitStruct.Banks = FLASH_BANK_1;
+    #endif
     #else
     EraseInitStruct.TypeErase = TYPEERASE_SECTORS;
     EraseInitStruct.VoltageRange = VOLTAGE_RANGE_3; // voltage range needs to be 2.7V to 3.6V
diff --git a/ports/stm/supervisor/internal_flash.h b/ports/stm/supervisor/internal_flash.h
index 68704805f3399..0ecfcbf12a0be 100644
--- a/ports/stm/supervisor/internal_flash.h
+++ b/ports/stm/supervisor/internal_flash.h
@@ -87,9 +87,15 @@
 #define INTERNAL_FLASH_FILESYSTEM_START_ADDR 0x08100000
 #endif
 
+#ifdef STM32L433xx
+#define STM32_FLASH_SIZE 0x40000 // 256KiB
+#define INTERNAL_FLASH_FILESYSTEM_SIZE 0xC000 // 48KiB
+#define INTERNAL_FLASH_FILESYSTEM_START_ADDR 0x08004000
+#endif
+
 #define INTERNAL_FLASH_FILESYSTEM_NUM_BLOCKS (INTERNAL_FLASH_FILESYSTEM_SIZE / FILESYSTEM_BLOCK_SIZE)
 
 #define STM32_FLASH_OFFSET 0x8000000 // All STM32 chips map to this flash location
 
 #define INTERNAL_FLASH_SYSTICK_MASK     (0x1ff) // 512ms
-#define INTERNAL_FLASH_IDLE_TICK(tick)  (((tick) & INTERNAL_FLASH_SYSTICK_MASK) == 2)
+#define INTERNAL_FLASH_IDLE_TICK(tick)  (((tick)&INTERNAL_FLASH_SYSTICK_MASK) == 2)
diff --git a/ports/stm/supervisor/usb.c b/ports/stm/supervisor/usb.c
index 61a7d54f08b74..86acdc49b34e6 100644
--- a/ports/stm/supervisor/usb.c
+++ b/ports/stm/supervisor/usb.c
@@ -29,7 +29,7 @@ static void init_usb_vbus_sense(void) {
     // B-peripheral session valid override enable
     USB_OTG_FS->GOTGCTL |= USB_OTG_GOTGCTL_BVALOEN;
     USB_OTG_FS->GOTGCTL |= USB_OTG_GOTGCTL_BVALOVAL;
-    #else
+    #elif !defined(STM32L433XX)
     USB_OTG_FS->GCCFG |= USB_OTG_GCCFG_NOVBUSSENS;
     USB_OTG_FS->GCCFG &= ~USB_OTG_GCCFG_VBUSBSEN;
     USB_OTG_FS->GCCFG &= ~USB_OTG_GCCFG_VBUSASEN;
@@ -56,7 +56,7 @@ void init_usb_hardware(void) {
 
     GPIO_InitTypeDef GPIO_InitStruct = {0};
     /**USB_OTG_FS GPIO Configuration
-    PA10     ------> USB_OTG_FS_ID
+    PA10     ------> USB_OTG_FS_ID (not present on STM32L433)
     PA11     ------> USB_OTG_FS_DM
     PA12     ------> USB_OTG_FS_DP
     */
@@ -69,8 +69,10 @@ void init_usb_hardware(void) {
     GPIO_InitStruct.Pull = GPIO_NOPULL;
     #if CPY_STM32H7
     GPIO_InitStruct.Alternate = GPIO_AF10_OTG1_FS;
-    #elif CPY_STM32F4 || CPY_STM32F7 || CPY_STM32L4
+    #elif CPY_STM32F4 || CPY_STM32F7 || defined(STM32L4R5XX)
     GPIO_InitStruct.Alternate = GPIO_AF10_OTG_FS;
+    #elif defined(STM32L433XX)
+    GPIO_InitStruct.Alternate = GPIO_AF10_USB_FS;
     #endif
     HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
     never_reset_pin_number(0, 11);
@@ -117,12 +119,13 @@ void init_usb_hardware(void) {
     #if CPY_STM32H7
     HAL_PWREx_EnableUSBVoltageDetector();
     __HAL_RCC_USB2_OTG_FS_CLK_ENABLE();
-    #else
+    #elif CPY_STM32F4 || CPY_STM32F7 || defined(STM32L4R5XX)
     /* Peripheral clock enable */
     __HAL_RCC_USB_OTG_FS_CLK_ENABLE();
+    #else
+    __HAL_RCC_USB_CLK_ENABLE();
     #endif
 
-
     init_usb_vbus_sense();
 }
 
diff --git a/ports/unix/Makefile b/ports/unix/Makefile
index 526955b1ea5c9..cd0403a8f5df5 100644
--- a/ports/unix/Makefile
+++ b/ports/unix/Makefile
@@ -4,8 +4,9 @@ ifdef VARIANT_DIR
 # the path as the variant name.
 VARIANT ?= $(notdir $(VARIANT_DIR:/=))
 else
-# If not given on the command line, then default to standard.
-VARIANT ?= standard
+# CIRCUITPY-CHANGE: default variant is coverage
+# If not given on the command line, then default to coverage.
+VARIANT ?= coverage
 VARIANT_DIR ?= variants/$(VARIANT)
 endif
 
diff --git a/ports/unix/variants/coverage/mpconfigvariant.mk b/ports/unix/variants/coverage/mpconfigvariant.mk
index e250fbe9b2dac..80491823e492d 100644
--- a/ports/unix/variants/coverage/mpconfigvariant.mk
+++ b/ports/unix/variants/coverage/mpconfigvariant.mk
@@ -33,6 +33,10 @@ SRC_BITMAP := \
 	shared-bindings/audiocore/__init__.c \
 	shared-bindings/audiocore/RawSample.c \
 	shared-bindings/audiocore/WaveFile.c \
+	shared-bindings/audiodelays/Echo.c \
+	shared-bindings/audiodelays/__init__.c \
+	shared-bindings/audiofilters/Filter.c \
+	shared-bindings/audiofilters/__init__.c \
 	shared-bindings/audiomixer/__init__.c \
 	shared-bindings/audiomixer/Mixer.c \
 	shared-bindings/audiomixer/MixerVoice.c \
@@ -70,6 +74,10 @@ SRC_BITMAP := \
 	shared-module/audiocore/__init__.c \
 	shared-module/audiocore/RawSample.c \
 	shared-module/audiocore/WaveFile.c \
+	shared-module/audiodelays/Echo.c \
+	shared-module/audiodelays/__init__.c \
+	shared-module/audiofilters/Filter.c \
+	shared-module/audiofilters/__init__.c \
 	shared-module/audiomixer/__init__.c \
 	shared-module/audiomp3/MP3Decoder.c \
 	shared-module/audiomixer/Mixer.c \
@@ -127,6 +135,9 @@ $(BUILD)/lib/mp3/src/buffers.o: CFLAGS += -include "shared-module/audiomp3/__ini
 CFLAGS += \
 	-DCIRCUITPY_AESIO=1 \
 	-DCIRCUITPY_AUDIOCORE=1 \
+	-DCIRCUITPY_AUDIOEFFECTS=1 \
+	-DCIRCUITPY_AUDIODELAYS=1 \
+	-DCIRCUITPY_AUDIOFILTERS=1 \
 	-DCIRCUITPY_AUDIOMIXER=1 \
 	-DCIRCUITPY_AUDIOMP3=1 \
 	-DCIRCUITPY_AUDIOMP3_USE_PORT_ALLOCATOR=0 \
diff --git a/py/circuitpy_mpconfig.h b/py/circuitpy_mpconfig.h
index adb881ebac23a..eacfbfbeb77c2 100644
--- a/py/circuitpy_mpconfig.h
+++ b/py/circuitpy_mpconfig.h
@@ -599,3 +599,19 @@ void background_callback_run_all(void);
 // Enable compiler functionality.
 #define MICROPY_ENABLE_COMPILER (1)
 #define MICROPY_PY_BUILTINS_COMPILE (1)
+
+#ifndef CIRCUITPY_MIN_GCC_VERSION
+#define CIRCUITPY_MIN_GCC_VERSION 13
+#endif
+
+#if defined(__GNUC__)
+#if __GNUC__ < CIRCUITPY_MIN_GCC_VERSION
+// (the 3 level scheme here is required to get expansion & stringization
+// correct)
+#define DO_PRAGMA(x) _Pragma(#x)
+#define DO_ERROR_HELPER(x) DO_PRAGMA(GCC error #x)
+#define DO_ERROR(x) DO_ERROR_HELPER(Minimum GCC version x \
+    -- older versions are known to miscompile CircuitPython)
+DO_ERROR(CIRCUITPY_MIN_GCC_VERSION);
+#endif
+#endif
diff --git a/py/circuitpy_mpconfig.mk b/py/circuitpy_mpconfig.mk
index e425552911929..1a831dbf314b5 100644
--- a/py/circuitpy_mpconfig.mk
+++ b/py/circuitpy_mpconfig.mk
@@ -697,6 +697,10 @@ CFLAGS += -DCIRCUITPY_TUSB_ATTR_USBRAM=$(CIRCUITPY_TUSB_ATTR_USBRAM)
 CIRCUITPY_SWO_TRACE ?= 0
 CFLAGS += -DCIRCUITPY_SWO_TRACE=$(CIRCUITPY_SWO_TRACE)
 
+# Check for a minimum GCC version during build (set to 0 to disable)
+CIRCUITPY_MIN_GCC_VERSION ?= 13
+CFLAGS += -DCIRCUITPY_MIN_GCC_VERSION=$(CIRCUITPY_MIN_GCC_VERSION)
+
 # Define an equivalent for MICROPY_LONGINT_IMPL, to pass to $(MPY-TOOL) in py/mkrules.mk
 # $(MPY-TOOL) needs to know what kind of longint to use (if any) to freeze long integers.
 # This should correspond to the MICROPY_LONGINT_IMPL definition in mpconfigport.h.
diff --git a/py/obj.c b/py/obj.c
index afbc62a65fcee..a825efc3c5a8f 100644
--- a/py/obj.c
+++ b/py/obj.c
@@ -144,6 +144,13 @@ void mp_obj_print_helper(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t
     }
     #endif
     const mp_obj_type_t *type = mp_obj_get_type(o_in);
+    // CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
+    #if MICROPY_PY_JSON
+    if (kind == PRINT_JSON && !(type->flags & MP_TYPE_FLAG_PRINT_JSON)) {
+        mp_raise_msg_varg(&mp_type_TypeError,
+            MP_ERROR_TEXT("can't convert %q to %q"), type->name, MP_QSTR_json);
+    }
+    #endif
     if (MP_OBJ_TYPE_HAS_SLOT(type, print)) {
         MP_OBJ_TYPE_GET_SLOT(type, print)((mp_print_t *)print, o_in, kind);
     } else {
diff --git a/py/obj.h b/py/obj.h
index 70fdeeebde4d6..255a00b314f5e 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -581,6 +581,8 @@ typedef mp_obj_t (*mp_fun_kw_t)(size_t n, const mp_obj_t *, mp_map_t *);
 #define MP_TYPE_FLAG_ITER_IS_CUSTOM (0x0100)
 #define MP_TYPE_FLAG_ITER_IS_STREAM (MP_TYPE_FLAG_ITER_IS_ITERNEXT | MP_TYPE_FLAG_ITER_IS_CUSTOM)
 #define MP_TYPE_FLAG_INSTANCE_TYPE (0x0200)
+// CIRCUITPY-CHANGE: check for valid types in json dumps
+#define MP_TYPE_FLAG_PRINT_JSON (0x0400)
 
 typedef enum {
     PRINT_STR = 0,
diff --git a/py/objbool.c b/py/objbool.c
index 5b3e3660e9510..990f52bb26fe4 100644
--- a/py/objbool.c
+++ b/py/objbool.c
@@ -84,11 +84,12 @@ static mp_obj_t bool_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs_
     return mp_binary_op(op, MP_OBJ_NEW_SMALL_INT(value), rhs_in);
 }
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     // can match all numeric types
     mp_type_bool,
     MP_QSTR_bool,
-    MP_TYPE_FLAG_EQ_CHECKS_OTHER_TYPE,
+    MP_TYPE_FLAG_EQ_CHECKS_OTHER_TYPE | MP_TYPE_FLAG_PRINT_JSON,
     make_new, bool_make_new,
     print, bool_print,
     unary_op, bool_unary_op,
diff --git a/py/objdict.c b/py/objdict.c
index 96a659d36e048..7094a1c1f99f2 100644
--- a/py/objdict.c
+++ b/py/objdict.c
@@ -710,10 +710,11 @@ static const mp_rom_map_elem_t dict_locals_dict_table[] = {
 
 static MP_DEFINE_CONST_DICT(dict_locals_dict, dict_locals_dict_table);
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_dict,
     MP_QSTR_dict,
-    MP_TYPE_FLAG_ITER_IS_GETITER,
+    MP_TYPE_FLAG_ITER_IS_GETITER | MP_TYPE_FLAG_PRINT_JSON,
     make_new, mp_obj_dict_make_new,
     print, dict_print,
     unary_op, dict_unary_op,
@@ -724,10 +725,11 @@ MP_DEFINE_CONST_OBJ_TYPE(
     );
 
 #if MICROPY_PY_COLLECTIONS_ORDEREDDICT
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_ordereddict,
     MP_QSTR_OrderedDict,
-    MP_TYPE_FLAG_ITER_IS_GETITER,
+    MP_TYPE_FLAG_ITER_IS_GETITER | MP_TYPE_FLAG_PRINT_JSON,
     make_new, mp_obj_dict_make_new,
     print, dict_print,
     unary_op, dict_unary_op,
diff --git a/py/objfloat.c b/py/objfloat.c
index b3a1f692594ad..6f248cdadfc9e 100644
--- a/py/objfloat.c
+++ b/py/objfloat.c
@@ -186,8 +186,9 @@ static mp_obj_t float_binary_op(mp_binary_op_t op, mp_obj_t lhs_in, mp_obj_t rhs
     return mp_obj_float_binary_op(op, lhs_val, rhs_in);
 }
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
-    mp_type_float, MP_QSTR_float, MP_TYPE_FLAG_EQ_NOT_REFLEXIVE | MP_TYPE_FLAG_EQ_CHECKS_OTHER_TYPE,
+    mp_type_float, MP_QSTR_float, MP_TYPE_FLAG_EQ_NOT_REFLEXIVE | MP_TYPE_FLAG_EQ_CHECKS_OTHER_TYPE | MP_TYPE_FLAG_PRINT_JSON,
     make_new, float_make_new,
     print, float_print,
     unary_op, float_unary_op,
diff --git a/py/objint.c b/py/objint.c
index 197625ced815c..7895f4f201ed3 100644
--- a/py/objint.c
+++ b/py/objint.c
@@ -588,10 +588,11 @@ static const mp_rom_map_elem_t int_locals_dict_table[] = {
 
 static MP_DEFINE_CONST_DICT(int_locals_dict, int_locals_dict_table);
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_int,
     MP_QSTR_int,
-    MP_TYPE_FLAG_NONE,
+    MP_TYPE_FLAG_PRINT_JSON,
     make_new, mp_obj_int_make_new,
     print, mp_obj_int_print,
     unary_op, mp_obj_int_unary_op,
diff --git a/py/objlist.c b/py/objlist.c
index 475002239ca76..2c1545d877715 100644
--- a/py/objlist.c
+++ b/py/objlist.c
@@ -485,10 +485,11 @@ static const mp_rom_map_elem_t list_locals_dict_table[] = {
 
 static MP_DEFINE_CONST_DICT(list_locals_dict, list_locals_dict_table);
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_list,
     MP_QSTR_list,
-    MP_TYPE_FLAG_ITER_IS_GETITER,
+    MP_TYPE_FLAG_ITER_IS_GETITER | MP_TYPE_FLAG_PRINT_JSON,
     make_new, mp_obj_list_make_new,
     print, list_print,
     unary_op, list_unary_op,
diff --git a/py/objnone.c b/py/objnone.c
index a8ce8ebfedf82..1e2016abd9fb7 100644
--- a/py/objnone.c
+++ b/py/objnone.c
@@ -43,10 +43,11 @@ static void none_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_
     }
 }
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_NoneType,
     MP_QSTR_NoneType,
-    MP_TYPE_FLAG_NONE,
+    MP_TYPE_FLAG_PRINT_JSON,
     print, none_print
     );
 
diff --git a/py/objstr.c b/py/objstr.c
index 0b2517197a0bd..342affb514dd4 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -2203,10 +2203,11 @@ MP_DEFINE_CONST_DICT_WITH_SIZE(mp_obj_memoryview_locals_dict,
 #if !MICROPY_PY_BUILTINS_STR_UNICODE
 static mp_obj_t mp_obj_new_str_iterator(mp_obj_t str, mp_obj_iter_buf_t *iter_buf);
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_str,
     MP_QSTR_str,
-    MP_TYPE_FLAG_NONE,
+    MP_TYPE_FLAG_PRINT_JSON,
     make_new, mp_obj_str_make_new,
     print, str_print,
     binary_op, mp_obj_str_binary_op,
diff --git a/py/objstrunicode.c b/py/objstrunicode.c
index 203d3858e60da..a158b91236588 100644
--- a/py/objstrunicode.c
+++ b/py/objstrunicode.c
@@ -236,10 +236,11 @@ static mp_obj_t str_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {
     }
 }
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_str,
     MP_QSTR_str,
-    MP_TYPE_FLAG_ITER_IS_GETITER,
+    MP_TYPE_FLAG_ITER_IS_GETITER | MP_TYPE_FLAG_PRINT_JSON,
     make_new, mp_obj_str_make_new,
     print, uni_print,
     unary_op, uni_unary_op,
diff --git a/py/objtuple.c b/py/objtuple.c
index afa80799af58e..ec1545abb84ea 100644
--- a/py/objtuple.c
+++ b/py/objtuple.c
@@ -232,10 +232,11 @@ static const mp_rom_map_elem_t tuple_locals_dict_table[] = {
 
 static MP_DEFINE_CONST_DICT(tuple_locals_dict, tuple_locals_dict_table);
 
+// CIRCUITPY-CHANGE: Diagnose json.dump on invalid types
 MP_DEFINE_CONST_OBJ_TYPE(
     mp_type_tuple,
     MP_QSTR_tuple,
-    MP_TYPE_FLAG_ITER_IS_GETITER,
+    MP_TYPE_FLAG_ITER_IS_GETITER | MP_TYPE_FLAG_PRINT_JSON,
     make_new, mp_obj_tuple_make_new,
     print, mp_obj_tuple_print,
     unary_op, mp_obj_tuple_unary_op,
diff --git a/shared-bindings/synthio/Note.c b/shared-bindings/synthio/Note.c
index c886f106a4cfd..9e588edefd1a9 100644
--- a/shared-bindings/synthio/Note.c
+++ b/shared-bindings/synthio/Note.c
@@ -20,15 +20,15 @@ static const mp_arg_t note_properties[] = {
     { MP_QSTR_amplitude, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(1) } },
     { MP_QSTR_bend, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(0) } },
     { MP_QSTR_waveform, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE } },
-    { MP_QSTR_waveform_loop_start, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0) } },
-    { MP_QSTR_waveform_loop_end, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(SYNTHIO_WAVEFORM_SIZE) } },
+    { MP_QSTR_waveform_loop_start, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(0) } },
+    { MP_QSTR_waveform_loop_end, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(SYNTHIO_WAVEFORM_SIZE) } },
     { MP_QSTR_envelope, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE } },
     { MP_QSTR_filter, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE } },
-    { MP_QSTR_ring_frequency, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0) } },
-    { MP_QSTR_ring_bend, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0) } },
+    { MP_QSTR_ring_frequency, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(0) } },
+    { MP_QSTR_ring_bend, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(0) } },
     { MP_QSTR_ring_waveform, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_NONE } },
-    { MP_QSTR_ring_waveform_loop_start, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0) } },
-    { MP_QSTR_ring_waveform_loop_end, MP_ARG_OBJ, {.u_obj = MP_ROM_INT(SYNTHIO_WAVEFORM_SIZE) } },
+    { MP_QSTR_ring_waveform_loop_start, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(0) } },
+    { MP_QSTR_ring_waveform_loop_end, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = MP_ROM_INT(SYNTHIO_WAVEFORM_SIZE) } },
 };
 //| class Note:
 //|     def __init__(
@@ -37,17 +37,17 @@ static const mp_arg_t note_properties[] = {
 //|         frequency: float,
 //|         panning: BlockInput = 0.0,
 //|         waveform: Optional[ReadableBuffer] = None,
-//|         waveform_loop_start: int = 0,
-//|         waveform_loop_end: int = waveform_max_length,
+//|         waveform_loop_start: BlockInput = 0,
+//|         waveform_loop_end: BlockInput = waveform_max_length,
 //|         envelope: Optional[Envelope] = None,
-//|         amplitude: BlockInput = 0.0,
+//|         amplitude: BlockInput = 1.0,
 //|         bend: BlockInput = 0.0,
 //|         filter: Optional[Biquad] = None,
 //|         ring_frequency: float = 0.0,
 //|         ring_bend: float = 0.0,
 //|         ring_waveform: Optional[ReadableBuffer] = None,
-//|         ring_waveform_loop_start: int = 0,
-//|         ring_waveform_loop_end: int = waveform_max_length,
+//|         ring_waveform_loop_start: BlockInput = 0,
+//|         ring_waveform_loop_end: BlockInput = waveform_max_length,
 //|     ) -> None:
 //|         """Construct a Note object, with a frequency in Hz, and optional panning, waveform, envelope, tremolo (volume change) and bend (frequency change).
 //|
@@ -198,21 +198,21 @@ MP_PROPERTY_GETSET(synthio_note_waveform_obj,
     (mp_obj_t)&synthio_note_get_waveform_obj,
     (mp_obj_t)&synthio_note_set_waveform_obj);
 
-//|     waveform_loop_start: int
+
+
+//|     waveform_loop_start: BlockInput
 //|     """The sample index of where to begin looping waveform data.
 //|
-//|     Values outside the range ``0`` to ``waveform_max_length-1`` (inclusive) are rejected with a `ValueError`.
-//|
-//|     Values greater than or equal to the actual waveform length are treated as 0."""
+//|     The value is limited to the range ``0`` to ``len(waveform)-1`` (inclusive)."""
 static mp_obj_t synthio_note_get_waveform_loop_start(mp_obj_t self_in) {
     synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    return mp_obj_new_int(common_hal_synthio_note_get_waveform_loop_start(self));
+    return common_hal_synthio_note_get_waveform_loop_start(self);
 }
 MP_DEFINE_CONST_FUN_OBJ_1(synthio_note_get_waveform_loop_start_obj, synthio_note_get_waveform_loop_start);
 
 static mp_obj_t synthio_note_set_waveform_loop_start(mp_obj_t self_in, mp_obj_t arg) {
     synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    common_hal_synthio_note_set_waveform_loop_start(self, mp_obj_get_int(arg));
+    common_hal_synthio_note_set_waveform_loop_start(self, arg);
     return mp_const_none;
 }
 MP_DEFINE_CONST_FUN_OBJ_2(synthio_note_set_waveform_loop_start_obj, synthio_note_set_waveform_loop_start);
@@ -220,24 +220,22 @@ MP_PROPERTY_GETSET(synthio_note_waveform_loop_start_obj,
     (mp_obj_t)&synthio_note_get_waveform_loop_start_obj,
     (mp_obj_t)&synthio_note_set_waveform_loop_start_obj);
 
-//|     waveform_loop_end: int
+//|     waveform_loop_end: BlockInput
 //|     """The sample index of where to end looping waveform data.
 //|
-//|     Values outside the range ``1`` to ``waveform_max_length`` (inclusive) are rejected with a `ValueError`.
-//|
-//|     If the value is greater than the actual waveform length, or less than or equal to the loop start, the loop will occur at the end of the waveform.
+//|     The value is limited to the range ``waveform_loop_start+1`` to ``len(waveform)`` (inclusive).
 //|
 //|     Use the `synthio.waveform_max_length` constant to set the loop point at the end of the wave form, no matter its length."""
 //|
 static mp_obj_t synthio_note_get_waveform_loop_end(mp_obj_t self_in) {
     synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    return mp_obj_new_int(common_hal_synthio_note_get_waveform_loop_end(self));
+    return common_hal_synthio_note_get_waveform_loop_end(self);
 }
 MP_DEFINE_CONST_FUN_OBJ_1(synthio_note_get_waveform_loop_end_obj, synthio_note_get_waveform_loop_end);
 
 static mp_obj_t synthio_note_set_waveform_loop_end(mp_obj_t self_in, mp_obj_t arg) {
     synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    common_hal_synthio_note_set_waveform_loop_end(self, mp_obj_get_int(arg));
+    common_hal_synthio_note_set_waveform_loop_end(self, arg);
     return mp_const_none;
 }
 MP_DEFINE_CONST_FUN_OBJ_2(synthio_note_set_waveform_loop_end_obj, synthio_note_set_waveform_loop_end);
@@ -331,21 +329,19 @@ MP_PROPERTY_GETSET(synthio_note_ring_waveform_obj,
     (mp_obj_t)&synthio_note_get_ring_waveform_obj,
     (mp_obj_t)&synthio_note_set_ring_waveform_obj);
 
-//|     ring_waveform_loop_start: int
+//|     ring_waveform_loop_start: BlockInput
 //|     """The sample index of where to begin looping waveform data.
 //|
-//|     Values outside the range ``0`` to ``waveform_max_length-1`` (inclusive) are rejected with a `ValueError`.
-//|
-//|     Values greater than or equal to the actual waveform length are treated as 0."""
+//|     The value is limited to the range ``0`` to ``len(ring_waveform)-1`` (inclusive)."""
 static mp_obj_t synthio_note_get_ring_waveform_loop_start(mp_obj_t self_in) {
     synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    return mp_obj_new_int(common_hal_synthio_note_get_ring_waveform_loop_start(self));
+    return common_hal_synthio_note_get_ring_waveform_loop_start(self);
 }
 MP_DEFINE_CONST_FUN_OBJ_1(synthio_note_get_ring_waveform_loop_start_obj, synthio_note_get_ring_waveform_loop_start);
 
 static mp_obj_t synthio_note_set_ring_waveform_loop_start(mp_obj_t self_in, mp_obj_t arg) {
     synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    common_hal_synthio_note_set_ring_waveform_loop_start(self, mp_obj_get_int(arg));
+    common_hal_synthio_note_set_ring_waveform_loop_start(self, arg);
     return mp_const_none;
 }
 MP_DEFINE_CONST_FUN_OBJ_2(synthio_note_set_ring_waveform_loop_start_obj, synthio_note_set_ring_waveform_loop_start);
@@ -353,24 +349,22 @@ MP_PROPERTY_GETSET(synthio_note_ring_waveform_loop_start_obj,
     (mp_obj_t)&synthio_note_get_ring_waveform_loop_start_obj,
     (mp_obj_t)&synthio_note_set_ring_waveform_loop_start_obj);
 
-//|     ring_waveform_loop_end: int
+//|     ring_waveform_loop_end: BlockInput
 //|     """The sample index of where to end looping waveform data.
 //|
-//|     Values outside the range ``1`` to ``waveform_max_length`` (inclusive) are rejected with a `ValueError`.
-//|
-//|     If the value is greater than the actual waveform length, or less than or equal to the loop start, the loop will occur at the end of the waveform.
+//|     The value is limited to the range ``ring_waveform_loop_start+1`` to ``len(ring_waveform)`` (inclusive).
 //|
 //|     Use the `synthio.waveform_max_length` constant to set the loop point at the end of the wave form, no matter its length."""
 //|
 static mp_obj_t synthio_note_get_ring_waveform_loop_end(mp_obj_t self_in) {
     synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    return mp_obj_new_int(common_hal_synthio_note_get_ring_waveform_loop_end(self));
+    return common_hal_synthio_note_get_ring_waveform_loop_end(self);
 }
 MP_DEFINE_CONST_FUN_OBJ_1(synthio_note_get_ring_waveform_loop_end_obj, synthio_note_get_ring_waveform_loop_end);
 
 static mp_obj_t synthio_note_set_ring_waveform_loop_end(mp_obj_t self_in, mp_obj_t arg) {
     synthio_note_obj_t *self = MP_OBJ_TO_PTR(self_in);
-    common_hal_synthio_note_set_ring_waveform_loop_end(self, mp_obj_get_int(arg));
+    common_hal_synthio_note_set_ring_waveform_loop_end(self, arg);
     return mp_const_none;
 }
 MP_DEFINE_CONST_FUN_OBJ_2(synthio_note_set_ring_waveform_loop_end_obj, synthio_note_set_ring_waveform_loop_end);
diff --git a/shared-bindings/synthio/Note.h b/shared-bindings/synthio/Note.h
index 0ee450acfe467..707b9f2e10463 100644
--- a/shared-bindings/synthio/Note.h
+++ b/shared-bindings/synthio/Note.h
@@ -31,11 +31,11 @@ void common_hal_synthio_note_set_bend(synthio_note_obj_t *self, mp_obj_t value);
 mp_obj_t common_hal_synthio_note_get_waveform_obj(synthio_note_obj_t *self);
 void common_hal_synthio_note_set_waveform(synthio_note_obj_t *self, mp_obj_t value);
 
-mp_int_t common_hal_synthio_note_get_waveform_loop_start(synthio_note_obj_t *self);
-void common_hal_synthio_note_set_waveform_loop_start(synthio_note_obj_t *self, mp_int_t value_in);
+mp_obj_t common_hal_synthio_note_get_waveform_loop_start(synthio_note_obj_t *self);
+void common_hal_synthio_note_set_waveform_loop_start(synthio_note_obj_t *self, mp_obj_t value);
 
-mp_int_t common_hal_synthio_note_get_waveform_loop_end(synthio_note_obj_t *self);
-void common_hal_synthio_note_set_waveform_loop_end(synthio_note_obj_t *self, mp_int_t value_in);
+mp_obj_t common_hal_synthio_note_get_waveform_loop_end(synthio_note_obj_t *self);
+void common_hal_synthio_note_set_waveform_loop_end(synthio_note_obj_t *self, mp_obj_t value);
 
 mp_float_t common_hal_synthio_note_get_ring_frequency(synthio_note_obj_t *self);
 void common_hal_synthio_note_set_ring_frequency(synthio_note_obj_t *self, mp_float_t value);
@@ -46,11 +46,11 @@ void common_hal_synthio_note_set_ring_bend(synthio_note_obj_t *self, mp_obj_t va
 mp_obj_t common_hal_synthio_note_get_ring_waveform_obj(synthio_note_obj_t *self);
 void common_hal_synthio_note_set_ring_waveform(synthio_note_obj_t *self, mp_obj_t value);
 
-mp_int_t common_hal_synthio_note_get_ring_waveform_loop_start(synthio_note_obj_t *self);
-void common_hal_synthio_note_set_ring_waveform_loop_start(synthio_note_obj_t *self, mp_int_t value_in);
+mp_obj_t common_hal_synthio_note_get_ring_waveform_loop_start(synthio_note_obj_t *self);
+void common_hal_synthio_note_set_ring_waveform_loop_start(synthio_note_obj_t *self, mp_obj_t value);
 
-mp_int_t common_hal_synthio_note_get_ring_waveform_loop_end(synthio_note_obj_t *self);
-void common_hal_synthio_note_set_ring_waveform_loop_end(synthio_note_obj_t *self, mp_int_t value_in);
+mp_obj_t common_hal_synthio_note_get_ring_waveform_loop_end(synthio_note_obj_t *self);
+void common_hal_synthio_note_set_ring_waveform_loop_end(synthio_note_obj_t *self, mp_obj_t value);
 
 mp_obj_t common_hal_synthio_note_get_envelope_obj(synthio_note_obj_t *self);
 void common_hal_synthio_note_set_envelope(synthio_note_obj_t *self, mp_obj_t value);
diff --git a/shared-module/audiodelays/Echo.c b/shared-module/audiodelays/Echo.c
index 3f45162cb5e93..e4eeff48f4c33 100644
--- a/shared-module/audiodelays/Echo.c
+++ b/shared-module/audiodelays/Echo.c
@@ -77,7 +77,7 @@ void common_hal_audiodelays_echo_construct(audiodelays_echo_obj_t *self, uint32_
 
     // Allocate the echo buffer for the max possible delay, echo is always 16-bit
     self->max_delay_ms = max_delay_ms;
-    self->max_echo_buffer_len = self->sample_rate / 1000.0f * max_delay_ms * (self->channel_count * sizeof(uint16_t)); // bytes
+    self->max_echo_buffer_len = (uint32_t)(self->sample_rate / 1000.0f * max_delay_ms) * (self->channel_count * sizeof(uint16_t)); // bytes
     self->echo_buffer = m_malloc(self->max_echo_buffer_len);
     if (self->echo_buffer == NULL) {
         common_hal_audiodelays_echo_deinit(self);
@@ -129,11 +129,11 @@ void common_hal_audiodelays_echo_set_delay_ms(audiodelays_echo_obj_t *self, mp_o
 void recalculate_delay(audiodelays_echo_obj_t *self, mp_float_t f_delay_ms) {
     if (self->freq_shift) {
         // Calculate the rate of iteration over the echo buffer with 8 sub-bits
-        self->echo_buffer_rate = MAX(self->max_delay_ms / f_delay_ms * 256.0f, 1.0);
+        self->echo_buffer_rate = (uint32_t)MAX(self->max_delay_ms / f_delay_ms * MICROPY_FLOAT_CONST(256.0), MICROPY_FLOAT_CONST(1.0));
         self->echo_buffer_len = self->max_echo_buffer_len;
     } else {
         // Calculate the current echo buffer length in bytes
-        uint32_t new_echo_buffer_len = self->sample_rate / 1000.0f * f_delay_ms * (self->channel_count * sizeof(uint16_t));
+        uint32_t new_echo_buffer_len = (uint32_t)(self->sample_rate / MICROPY_FLOAT_CONST(1000.0) * f_delay_ms) * (self->channel_count * sizeof(uint16_t));
 
         // Check if our new echo is too long for our maximum buffer
         if (new_echo_buffer_len > self->max_echo_buffer_len) {
@@ -153,7 +153,7 @@ void recalculate_delay(audiodelays_echo_obj_t *self, mp_float_t f_delay_ms) {
         memset(self->echo_buffer + self->echo_buffer_len, 0, self->max_echo_buffer_len - self->echo_buffer_len);
     }
 
-    self->current_delay_ms = f_delay_ms;
+    self->current_delay_ms = (uint32_t)f_delay_ms;
 }
 
 mp_obj_t common_hal_audiodelays_echo_get_decay(audiodelays_echo_obj_t *self) {
@@ -342,7 +342,10 @@ audioio_get_buffer_result_t audiodelays_echo_get_buffer(audiodelays_echo_obj_t *
                 } else {
                     // For unsigned samples set to the middle which is "quiet"
                     if (MP_LIKELY(self->bits_per_sample == 16)) {
-                        memset(word_buffer, 32768, length * (self->bits_per_sample / 8));
+                        uint16_t *uword_buffer = (uint16_t *)word_buffer;
+                        while (length--) {
+                            *uword_buffer++ = 32768;
+                        }
                     } else {
                         memset(hword_buffer, 128, length * (self->bits_per_sample / 8));
                     }
@@ -357,17 +360,17 @@ audioio_get_buffer_result_t audiodelays_echo_get_buffer(audiodelays_echo_obj_t *
                         echo = echo_buffer[echo_buffer_pos >> 8];
                         next_buffer_pos = echo_buffer_pos + self->echo_buffer_rate;
 
-                        word = echo * decay;
+                        word = (int16_t)(echo * decay);
                         for (uint32_t j = echo_buffer_pos >> 8; j < next_buffer_pos >> 8; j++) {
                             echo_buffer[j % echo_buf_len] = word;
                         }
                     } else {
                         echo = echo_buffer[self->echo_buffer_read_pos++];
-                        word = echo * decay;
+                        word = (int16_t)(echo * decay);
                         echo_buffer[self->echo_buffer_write_pos++] = word;
                     }
 
-                    word = echo * mix;
+                    word = (int16_t)(echo * mix);
 
                     if (MP_LIKELY(self->bits_per_sample == 16)) {
                         word_buffer[i] = word;
@@ -430,10 +433,10 @@ audioio_get_buffer_result_t audiodelays_echo_get_buffer(audiodelays_echo_obj_t *
                     if (self->freq_shift) {
                         echo = echo_buffer[echo_buffer_pos >> 8];
                         next_buffer_pos = echo_buffer_pos + self->echo_buffer_rate;
-                        word = echo * decay + sample_word;
+                        word = (int32_t)(echo * decay + sample_word);
                     } else {
                         echo = echo_buffer[self->echo_buffer_read_pos++];
-                        word = echo * decay + sample_word;
+                        word = (int32_t)(echo * decay + sample_word);
                     }
 
                     if (MP_LIKELY(self->bits_per_sample == 16)) {
@@ -464,12 +467,12 @@ audioio_get_buffer_result_t audiodelays_echo_get_buffer(audiodelays_echo_obj_t *
                     word = echo + sample_word;
 
                     if (MP_LIKELY(self->bits_per_sample == 16)) {
-                        word_buffer[i] = (sample_word * (1.0 - mix)) + (word * mix);
+                        word_buffer[i] = (int16_t)((sample_word * (1.0 - mix)) + (word * mix));
                         if (!self->samples_signed) {
                             word_buffer[i] ^= 0x8000;
                         }
                     } else {
-                        int8_t mixed = (sample_word * (1.0 - mix)) + (word * mix);
+                        int8_t mixed = (int16_t)((sample_word * (1.0 - mix)) + (word * mix));
                         if (self->samples_signed) {
                             hword_buffer[i] = mixed;
                         } else {
diff --git a/shared-module/audiofilters/Filter.c b/shared-module/audiofilters/Filter.c
index 86edb6cb04183..6b8fc85dd4e27 100644
--- a/shared-module/audiofilters/Filter.c
+++ b/shared-module/audiofilters/Filter.c
@@ -204,6 +204,7 @@ int16_t mix_down_sample(int32_t sample) {
 
 audioio_get_buffer_result_t audiofilters_filter_get_buffer(audiofilters_filter_obj_t *self, bool single_channel_output, uint8_t channel,
     uint8_t **buffer, uint32_t *buffer_length) {
+    (void)channel;
 
     if (!single_channel_output) {
         channel = 0;
@@ -240,8 +241,24 @@ audioio_get_buffer_result_t audiofilters_filter_get_buffer(audiofilters_filter_o
             }
         }
 
-        // If we have a sample, filter it
-        if (self->sample != NULL) {
+        if (self->sample == NULL) {
+            if (self->samples_signed) {
+                memset(word_buffer, 0, length * (self->bits_per_sample / 8));
+            } else {
+                // For unsigned samples set to the middle which is "quiet"
+                if (MP_LIKELY(self->bits_per_sample == 16)) {
+                    uint16_t *uword_buffer = (uint16_t *)word_buffer;
+                    while (length--) {
+                        *uword_buffer++ = 32768;
+                    }
+                } else {
+                    memset(hword_buffer, 128, length * (self->bits_per_sample / 8));
+                }
+            }
+
+            length = 0;
+        } else {
+            // we have a sample to play and filter
             // Determine how many bytes we can process to our buffer, the less of the sample we have left and our buffer remaining
             uint32_t n = MIN(self->sample_buffer_length, length);
 
@@ -281,7 +298,7 @@ audioio_get_buffer_result_t audiofilters_filter_get_buffer(audiofilters_filter_o
                     // Mix processed signal with original sample and transfer to output buffer
                     for (uint32_t j = 0; j < n_samples; j++) {
                         if (MP_LIKELY(self->bits_per_sample == 16)) {
-                            word_buffer[i + j] = mix_down_sample((sample_src[i + j] * (1.0 - mix)) + (self->filter_buffer[j] * mix));
+                            word_buffer[i + j] = mix_down_sample((int32_t)((sample_src[i + j] * (MICROPY_FLOAT_CONST(1.0) - mix)) + (self->filter_buffer[j] * mix)));
                             if (!self->samples_signed) {
                                 word_buffer[i + j] ^= 0x8000;
                             }
@@ -289,7 +306,7 @@ audioio_get_buffer_result_t audiofilters_filter_get_buffer(audiofilters_filter_o
                             if (self->samples_signed) {
                                 hword_buffer[i + j] = (int8_t)((sample_hsrc[i + j] * (1.0 - mix)) + (self->filter_buffer[j] * mix));
                             } else {
-                                hword_buffer[i + j] = (uint8_t)(((int8_t)(((uint8_t)sample_hsrc[i + j]) ^ 0x80) * (1.0 - mix)) + (self->filter_buffer[j] * mix)) ^ 0x80;
+                                hword_buffer[i + j] = (uint8_t)(((int8_t)(((uint8_t)sample_hsrc[i + j]) ^ 0x80) * (MICROPY_FLOAT_CONST(1.0) - mix)) + (self->filter_buffer[j] * mix)) ^ 0x80;
                             }
                         }
                     }
diff --git a/shared-module/storage/__init__.c b/shared-module/storage/__init__.c
index 12486aff752f3..e64184c000bb6 100644
--- a/shared-module/storage/__init__.c
+++ b/shared-module/storage/__init__.c
@@ -264,6 +264,7 @@ void common_hal_storage_erase_filesystem(bool extended) {
     supervisor_flash_set_extended(extended);
     #endif
     (void)filesystem_init(false, true);  // Force a re-format. Ignore failure.
+    common_hal_mcu_on_next_reset(RUNMODE_NORMAL);
     common_hal_mcu_reset();
     // We won't actually get here, since we're resetting.
 }
diff --git a/shared-module/synthio/Note.c b/shared-module/synthio/Note.c
index 49dfbb7f429d3..0e612914ec700 100644
--- a/shared-module/synthio/Note.c
+++ b/shared-module/synthio/Note.c
@@ -100,22 +100,20 @@ void common_hal_synthio_note_set_waveform(synthio_note_obj_t *self, mp_obj_t wav
     self->waveform_obj = waveform_in;
 }
 
-mp_int_t common_hal_synthio_note_get_waveform_loop_start(synthio_note_obj_t *self) {
-    return self->waveform_loop_start;
+mp_obj_t common_hal_synthio_note_get_waveform_loop_start(synthio_note_obj_t *self) {
+    return self->waveform_loop_start.obj;
 }
 
-void common_hal_synthio_note_set_waveform_loop_start(synthio_note_obj_t *self, mp_int_t value_in) {
-    mp_int_t val = mp_arg_validate_int_range(value_in, 0, SYNTHIO_WAVEFORM_SIZE - 1, MP_QSTR_waveform_loop_start);
-    self->waveform_loop_start = val;
+void common_hal_synthio_note_set_waveform_loop_start(synthio_note_obj_t *self, mp_obj_t value_in) {
+    synthio_block_assign_slot(value_in, &self->waveform_loop_start, MP_QSTR_waveform_loop_start);
 }
 
-mp_int_t common_hal_synthio_note_get_waveform_loop_end(synthio_note_obj_t *self) {
-    return self->waveform_loop_end;
+mp_obj_t common_hal_synthio_note_get_waveform_loop_end(synthio_note_obj_t *self) {
+    return self->waveform_loop_end.obj;
 }
 
-void common_hal_synthio_note_set_waveform_loop_end(synthio_note_obj_t *self, mp_int_t value_in) {
-    mp_int_t val = mp_arg_validate_int_range(value_in, 1, SYNTHIO_WAVEFORM_SIZE, MP_QSTR_waveform_loop_end);
-    self->waveform_loop_end = val;
+void common_hal_synthio_note_set_waveform_loop_end(synthio_note_obj_t *self, mp_obj_t value_in) {
+    synthio_block_assign_slot(value_in, &self->waveform_loop_end, MP_QSTR_waveform_loop_end);
 }
 
 mp_obj_t common_hal_synthio_note_get_ring_waveform_obj(synthio_note_obj_t *self) {
@@ -133,22 +131,20 @@ void common_hal_synthio_note_set_ring_waveform(synthio_note_obj_t *self, mp_obj_
     self->ring_waveform_obj = ring_waveform_in;
 }
 
-mp_int_t common_hal_synthio_note_get_ring_waveform_loop_start(synthio_note_obj_t *self) {
-    return self->ring_waveform_loop_start;
+mp_obj_t common_hal_synthio_note_get_ring_waveform_loop_start(synthio_note_obj_t *self) {
+    return self->ring_waveform_loop_start.obj;
 }
 
-void common_hal_synthio_note_set_ring_waveform_loop_start(synthio_note_obj_t *self, mp_int_t value_in) {
-    mp_int_t val = mp_arg_validate_int_range(value_in, 0, SYNTHIO_WAVEFORM_SIZE - 1, MP_QSTR_ring_waveform_loop_start);
-    self->ring_waveform_loop_start = val;
+void common_hal_synthio_note_set_ring_waveform_loop_start(synthio_note_obj_t *self, mp_obj_t value_in) {
+    synthio_block_assign_slot(value_in, &self->ring_waveform_loop_start, MP_QSTR_ring_waveform_loop_start);
 }
 
-mp_int_t common_hal_synthio_note_get_ring_waveform_loop_end(synthio_note_obj_t *self) {
-    return self->ring_waveform_loop_end;
+mp_obj_t common_hal_synthio_note_get_ring_waveform_loop_end(synthio_note_obj_t *self) {
+    return self->ring_waveform_loop_end.obj;
 }
 
-void common_hal_synthio_note_set_ring_waveform_loop_end(synthio_note_obj_t *self, mp_int_t value_in) {
-    mp_int_t val = mp_arg_validate_int_range(value_in, 1, SYNTHIO_WAVEFORM_SIZE, MP_QSTR_ring_waveform_loop_end);
-    self->ring_waveform_loop_end = val;
+void common_hal_synthio_note_set_ring_waveform_loop_end(synthio_note_obj_t *self, mp_obj_t value_in) {
+    synthio_block_assign_slot(value_in, &self->ring_waveform_loop_end, MP_QSTR_ring_waveform_loop_end);
 }
 
 void synthio_note_recalculate(synthio_note_obj_t *self, int32_t sample_rate) {
diff --git a/shared-module/synthio/Note.h b/shared-module/synthio/Note.h
index dc4e5557fd3c9..9d9deb42ac8f3 100644
--- a/shared-module/synthio/Note.h
+++ b/shared-module/synthio/Note.h
@@ -28,9 +28,9 @@ typedef struct synthio_note_obj {
     int32_t ring_frequency_scaled, ring_frequency_bent;
 
     mp_buffer_info_t waveform_buf;
-    uint32_t waveform_loop_start, waveform_loop_end;
+    synthio_block_slot_t waveform_loop_start, waveform_loop_end;
     mp_buffer_info_t ring_waveform_buf;
-    uint32_t ring_waveform_loop_start, ring_waveform_loop_end;
+    synthio_block_slot_t ring_waveform_loop_start, ring_waveform_loop_end;
     synthio_envelope_definition_t envelope_def;
 } synthio_note_obj_t;
 
diff --git a/shared-module/synthio/__init__.c b/shared-module/synthio/__init__.c
index 630c3de86988c..be7e036660a84 100644
--- a/shared-module/synthio/__init__.c
+++ b/shared-module/synthio/__init__.c
@@ -184,23 +184,15 @@ static bool synth_note_into_buffer(synthio_synth_t *synth, int chan, int32_t *ou
         if (note->waveform_buf.buf) {
             waveform = note->waveform_buf.buf;
             waveform_length = note->waveform_buf.len;
-            if (note->waveform_loop_start > 0 && note->waveform_loop_start < waveform_length) {
-                waveform_start = note->waveform_loop_start;
-            }
-            if (note->waveform_loop_end > waveform_start && note->waveform_loop_end < waveform_length) {
-                waveform_length = note->waveform_loop_end;
-            }
+            waveform_start = (uint32_t)synthio_block_slot_get_limited(&note->waveform_loop_start, 0, waveform_length - 1);
+            waveform_length = (uint32_t)synthio_block_slot_get_limited(&note->waveform_loop_end, waveform_start + 1, waveform_length);
         }
         dds_rate = synthio_frequency_convert_scaled_to_dds((uint64_t)frequency_scaled * (waveform_length - waveform_start), sample_rate);
         if (note->ring_frequency_scaled != 0 && note->ring_waveform_buf.buf) {
             ring_waveform = note->ring_waveform_buf.buf;
             ring_waveform_length = note->ring_waveform_buf.len;
-            if (note->ring_waveform_loop_start > 0 && note->ring_waveform_loop_start < ring_waveform_length) {
-                ring_waveform_start = note->waveform_loop_start;
-            }
-            if (note->ring_waveform_loop_end > ring_waveform_start && note->ring_waveform_loop_end < ring_waveform_length) {
-                ring_waveform_length = note->ring_waveform_loop_end;
-            }
+            ring_waveform_start = (uint32_t)synthio_block_slot_get_limited(&note->ring_waveform_loop_start, 0, ring_waveform_length - 1);
+            ring_waveform_length = (uint32_t)synthio_block_slot_get_limited(&note->ring_waveform_loop_end, ring_waveform_start + 1, ring_waveform_length);
             ring_dds_rate = synthio_frequency_convert_scaled_to_dds((uint64_t)note->ring_frequency_bent * (ring_waveform_length - ring_waveform_start), sample_rate);
             uint32_t lim = ring_waveform_length << SYNTHIO_FREQUENCY_SHIFT;
             if (ring_dds_rate > lim / sizeof(int16_t)) {
diff --git a/tests/circuitpython/audiofilter_filter.py b/tests/circuitpython/audiofilter_filter.py
new file mode 100644
index 0000000000000..3267ded439790
--- /dev/null
+++ b/tests/circuitpython/audiofilter_filter.py
@@ -0,0 +1,16 @@
+from audiofilters import Filter
+from audiofilterhelper import synth_test, sine8k
+
+@synth_test
+def basic_filter():
+    effect = Filter(
+        bits_per_sample=16,
+        samples_signed=True,
+    )
+    yield effect, []
+
+    effect.play(sine8k, loop=True)
+    yield 4
+
+    effect.stop()
+    yield 2
diff --git a/tests/circuitpython/audiofilter_filter.py.exp b/tests/circuitpython/audiofilter_filter.py.exp
new file mode 100644
index 0000000000000..734ac16b3a799
--- /dev/null
+++ b/tests/circuitpython/audiofilter_filter.py.exp
@@ -0,0 +1,1536 @@
+0 0.0
+1 0.010467529296875
+2 0.02093505859375
+3 0.031402587890625
+4 0.0418701171875
+5 0.05230712890625
+6 0.062774658203125
+7 0.073211669921875
+8 0.083648681640625
+9 0.094085693359375
+10 0.104522705078125
+11 0.11492919921875
+12 0.12530517578125
+13 0.13568115234375
+14 0.14605712890625
+15 0.156402587890625
+16 0.166748046875
+17 0.17706298828125
+18 0.187347412109375
+19 0.1976318359375
+20 0.2078857421875
+21 0.218109130859375
+22 0.22833251953125
+23 0.238525390625
+24 0.2486572265625
+25 0.2587890625
+26 0.268890380859375
+27 0.278961181640625
+28 0.28900146484375
+29 0.29901123046875
+30 0.308990478515625
+31 0.318939208984375
+32 0.328826904296875
+33 0.338714599609375
+34 0.348541259765625
+35 0.35833740234375
+36 0.36810302734375
+37 0.3778076171875
+38 0.387481689453125
+39 0.397125244140625
+40 0.406707763671875
+41 0.416259765625
+42 0.425750732421875
+43 0.435211181640625
+44 0.444610595703125
+45 0.453948974609375
+46 0.4632568359375
+47 0.4725341796875
+48 0.481719970703125
+49 0.490875244140625
+50 0.499969482421875
+51 0.509002685546875
+52 0.51800537109375
+53 0.52691650390625
+54 0.535797119140625
+55 0.54461669921875
+56 0.5533447265625
+57 0.562042236328125
+58 0.5706787109375
+59 0.579254150390625
+60 0.587738037109375
+61 0.59619140625
+62 0.60455322265625
+63 0.612884521484375
+64 0.621124267578125
+65 0.6292724609375
+66 0.63739013671875
+67 0.645416259765625
+68 0.65338134765625
+69 0.661285400390625
+70 0.669097900390625
+71 0.676849365234375
+72 0.68450927734375
+73 0.692108154296875
+74 0.699615478515625
+75 0.707061767578125
+76 0.714447021484375
+77 0.721710205078125
+78 0.72894287109375
+79 0.736053466796875
+80 0.74310302734375
+81 0.75006103515625
+82 0.7569580078125
+83 0.763763427734375
+84 0.770477294921875
+85 0.777099609375
+86 0.783660888671875
+87 0.790130615234375
+88 0.796478271484375
+89 0.802764892578125
+90 0.808990478515625
+91 0.815093994140625
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diff --git a/tests/circuitpython/synthesizer_note.py.exp b/tests/circuitpython/synthesizer_note.py.exp
index 43d07e5e7da9c..7417a4c8a19fb 100644
--- a/tests/circuitpython/synthesizer_note.py.exp
+++ b/tests/circuitpython/synthesizer_note.py.exp
@@ -1,10 +1,10 @@
 ()
 [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
-(Note(frequency=830.6076004423605, panning=0.0, amplitude=1.0, bend=0.0, waveform=None, waveform_loop_start=0, waveform_loop_end=16384, envelope=None, filter=None, ring_frequency=0.0, ring_bend=0.0, ring_waveform=None, ring_waveform_loop_start=0, ring_waveform_loop_end=16384),)
+(Note(frequency=830.6076004423605, panning=0.0, amplitude=1.0, bend=0.0, waveform=None, waveform_loop_start=0.0, waveform_loop_end=16384.0, envelope=None, filter=None, ring_frequency=0.0, ring_bend=0.0, ring_waveform=None, ring_waveform_loop_start=0.0, ring_waveform_loop_end=16384.0),)
 [-16383, -16383, -16383, -16383, 16382, 16382, 16382, 16382, 16382, -16383, -16383, -16383, -16383, -16383, 16382, 16382, 16382, 16382, 16382, -16383, -16383, -16383, -16383, -16383]
-(Note(frequency=830.6076004423605, panning=0.0, amplitude=1.0, bend=0.0, waveform=None, waveform_loop_start=0, waveform_loop_end=16384, envelope=None, filter=None, ring_frequency=0.0, ring_bend=0.0, ring_waveform=None, ring_waveform_loop_start=0, ring_waveform_loop_end=16384), Note(frequency=830.6076004423605, panning=0.0, amplitude=1.0, bend=0.0, waveform=None, waveform_loop_start=0, waveform_loop_end=16384, envelope=None, filter=None, ring_frequency=0.0, ring_bend=0.0, ring_waveform=None, ring_waveform_loop_start=0, ring_waveform_loop_end=16384))
+(Note(frequency=830.6076004423605, panning=0.0, amplitude=1.0, bend=0.0, waveform=None, waveform_loop_start=0.0, waveform_loop_end=16384.0, envelope=None, filter=None, ring_frequency=0.0, ring_bend=0.0, ring_waveform=None, ring_waveform_loop_start=0.0, ring_waveform_loop_end=16384.0), Note(frequency=830.6076004423605, panning=0.0, amplitude=1.0, bend=0.0, waveform=None, waveform_loop_start=0.0, waveform_loop_end=16384.0, envelope=None, filter=None, ring_frequency=0.0, ring_bend=0.0, ring_waveform=None, ring_waveform_loop_start=0.0, ring_waveform_loop_end=16384.0))
 [-1, -1, -1, -1, -1, -1, -1, -1, 28045, -1, -1, -1, -1, -28046, -1, -1, -1, -1, 28045, -1, -1, -1, -1, -28046]
-(Note(frequency=830.6076004423605, panning=0.0, amplitude=1.0, bend=0.0, waveform=None, waveform_loop_start=0, waveform_loop_end=16384, envelope=None, filter=None, ring_frequency=0.0, ring_bend=0.0, ring_waveform=None, ring_waveform_loop_start=0, ring_waveform_loop_end=16384),)
+(Note(frequency=830.6076004423605, panning=0.0, amplitude=1.0, bend=0.0, waveform=None, waveform_loop_start=0.0, waveform_loop_end=16384.0, envelope=None, filter=None, ring_frequency=0.0, ring_bend=0.0, ring_waveform=None, ring_waveform_loop_start=0.0, ring_waveform_loop_end=16384.0),)
 [-1, -1, -1, 28045, -1, -1, -1, -1, -1, -1, -1, -1, 28045, -1, -1, -1, -1, -28046, -1, -1, -1, -1, 28045, -1]
 (-5242, 5241)
 (-10485, 10484)
diff --git a/tests/extmod/json_dumps_extra.py b/tests/extmod/json_dumps_extra.py
index 9074416a99d93..a410b0ee0ef63 100644
--- a/tests/extmod/json_dumps_extra.py
+++ b/tests/extmod/json_dumps_extra.py
@@ -1,9 +1,6 @@
 # test uPy json behaviour that's not valid in CPy
-
-try:
-    import json
-except ImportError:
-    print("SKIP")
-    raise SystemExit
+# CIRCUITPY-CHANGE: This behavior matches CPython
+print("SKIP")
+raise SystemExit
 
 print(json.dumps(b"1234"))
diff --git a/tests/testlib/audiofilterhelper.py b/tests/testlib/audiofilterhelper.py
new file mode 100644
index 0000000000000..15862dc398c71
--- /dev/null
+++ b/tests/testlib/audiofilterhelper.py
@@ -0,0 +1,26 @@
+import array
+from ulab import numpy as np
+from math import sin, pi, ceil
+from audiocore import get_buffer, RawSample
+from synthio import Note, LFO, MathOperation, Synthesizer
+
+sinedata = array.array("h", [int(32767 * sin(i * 2 * pi / 600)) for i in range(600)])
+sine8k = RawSample(sinedata, sample_rate=8000)
+
+def synth_test(_gen=None, dtype=np.int16, divisor = 32768, channel_count=1):
+    def func(gen):
+        g = gen()
+        synth, blocks = next(g)
+        t = 0
+        for nframes in g:
+            for i in range(nframes):
+                samples = np.frombuffer(get_buffer(synth)[1], dtype=dtype) / divisor
+                block_values = [b.value for b in blocks]
+                for k in range(0, len(samples), channel_count):
+                    print(t, *(list(samples[k : k + channel_count]) + block_values))
+                    t += 1
+
+    if _gen is None:
+        return func
+    else:
+        func(_gen)