ESP32 LoRa Temperature & Humidity System

This project consists of two ESP32-based nodes communicating via LoRa. The client node reads temperature and humidity from a sensor, sends it every 5 seconds to the server node, and listens for commands (relay_on, relay_off). The server node connects to WiFi & Blynk, forwards data to Blynk, and relays control commands back to the client node.

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📋 Features

✅ Client node:

• Reads temperature & humidity
• Sends data over LoRa every 5 seconds
• Receives relay control commands (relay_on, relay_off) over LoRa

✅ Server node:

• Connects to WiFi & Blynk cloud
• Receives data from client over LoRa
• Sends data to Blynk every 15 minutes
• Receives commands from Blynk and forwards them to client over LoRa

🛠 Hardware

• 2 × ESP32 Dev Boards
• 2 × LoRa SX1278 modules
• 1 × DHT11 or similar temperature & humidity sensor
• 1 × Relay module
• Jumper wires, breadboard or PCB

📁 File Structure

.
├── lora_client/lora_client.ino         # LoRa client (sensor) code
├── lora_server/lora_server.ino         # LoRa server (WiFi & Blynk) code
├── lora_server/secret.h            # WiFi & Blynk credentials (not tracked in git)
├── .gitignore          # ignores secret.h and build artifacts
├── README.md           # this file
├── LICENSE             # license file

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🔒 Secrets

Create a secret.h file in the lora server project folder (excluded from git) with:

#define BLYNK_TEMPLATE_ID "YourTemplateId"
#define BLYNK_TEMPLATE_NAME "YourBlynkTemplateName"
#define BLYNK_AUTH_TOKEN "YourBlynkToken"

#define WIFI_SSID     "YourWifiSSID"
#define WIFI_PASSWORD "YourWifiPassword"

🚀 Getting Started

On the client node:

Flash client.ino to ESP32 #1.
Connect LoRa module & sensor.
Power it on.

On the server node:

Flash server.ino to ESP32 #2.
Connect LoRa module.
Make sure secret.h is configured with your WiFi & Blynk credentials.

Power it on.

On Blynk:

Create a new project.
Add widgets for temperature, humidity, and buttons to control relay.
Use the auth token in secret.h.

📖 License MIT License © uugan