An RP2040-based 16-output Harp-compliant Clock Synchronizer.

This device can serve as a drop-in replacement for the Harp-Tech Clock Synchronizer with added capabilities.

Features

• 16 output channels for distributing clocks to other devices
• 1 input channel for receiving and synchronizing to another clock source
• 1 Additional Auxiliary Output, providing one of the following at a time:
  • PPS output
  • serial output of the time at user-specifiable baud-rate
• "Used channel detection." Device can identify which channels are in use.

Ordering ➡ 💸

You can now order V1.0.0 from PCBWay:

• white-rabbit board. Select PCB + Assembly

These printed circuit boards are made on-demand.

You will also need:

• 3D Printed Enclosure Walls and Laser Cut Lids
  • right click the component to export each part.

Auxiliary Output

This device features an auxiliary output that can either produce a pulse-per-second (PPS) or UART message at the start of the whole second. This external signa enables Harp devices to additionally further synchronize with non-Harp devices.

PPS Output

This device optionally outputs a 1[Hz] signal with a 50% duty cycle on the whole second. Error from the nominal Harp time is < 1[us].

This feature is available on the AUX Port (3-pin terminal block).

AUX UART Output

This device optionally outputs a the current time in seconds at the start of the whole second. Error from the nominal Harp time is < 3[us].

This feature is available on the AUX Port (3-pin terminal block), and the baud rate is configurable via Harp Protocol (U32 in Register 36).

PCBA Enclosure

For the enclosure design, see the companion OnShape project.

Developer Notes

In the firmware's CMakeLists.txt, adding (or uncommenting) the debug message below:

add_definitions(-DDEBUG)

will override the Auxiliary port behavior to use the auxiliary uart for printf-style debug messages. PPS and AUX UART features will not be available in debug mode.