ESP32 Wi-Fi and MQTT to LoRa UART gateway bridging Home Assistant commands to remote garden watering solenoids.
Status: in progress
What it does
- Connects to Wi-Fi network and subscribes to Home Assistant MQTT topics (
homeassistant/ESP32/control) - Receives irrigation schedule triggers and valve pulse duration commands from Home Assistant
- Converts incoming MQTT messages into long-range LoRa packets over Serial2 (TX GPIO 17, RX GPIO 16)
- Controls remote battery-powered solenoid watering nodes across the garden without Wi-Fi coverage
Bill of Materials
| Part | Quantity | Purpose |
|---|---|---|
| ESP32 Development Board | 1 | Microcontroller handling Wi-Fi, PubSubClient MQTT, and UART bridge |
| RA-01 LoRa SX1278 Module | 1 | 433MHz / 915MHz UART LoRa transceiver connected to Serial2 (pins 16/17) |
| 12V DC Solenoid Water Valve | 1 | Remote irrigation control valve operated by distant LoRa receiver node |
| MOSFET Driver / Relay Module | 1 | High-current valve actuator driver circuit on receiver node |
How it works
The central ESP32 bridge stays connected to the local MQTT broker (192.168.20.30). When Home Assistant publishes a watering trigger to homeassistant/ESP32/control, the callback function captures the payload and immediately re-transmits it via UART (Serial2 at 9600 baud on pins 16/17) to the RA-01 LoRa transmitter, reaching valves up to hundreds of meters away.
What broke
- Software serial baud rate mismatches initially corrupted LoRa packets; switching to hardware UART (
Serial2on GPIO 16/17) eliminated buffer overruns and frame drops.
Links
- Gitea Repository: sam/LoraMqttWatering