Wiring Instructions
The voltage level of the ESP32 UART is 3.3V!
Make sure your flight controller also uses 3.3V. Pixhawk flight controllers do have a 3.3V UART by default and a 5V power supply line. These flight controllers will not cause any issues.
Just connect the board to your flight controller using the provided cable.
You can use any of the available pins for connecting your flight controller except for the TX & RX labeled pins (D6 & D7).
The below image shows an example on how to connect to the pixhawk telemetry port.
- Connect the pixhawk telemetry TX pin to a free the ESP32C3 pin (except for the pins D6 & D7) - note the GPIO number, not the D#!
- Connect the pixhawk telemetry RX pin to a free the ESP32C3 pin (except for the pins D6 & D7) - note the GPIO number, not the D#!
- Connect the pixhawk telemetry GND pin to ESP32C3 GND pin
- Connect the pixhawk telemetry 5V out pin to ESP32C3 5V pin
You can use any of the available pins for connecting your flight controller/UART except for the TX & RX labeled pins of your dev. board.
The reason for that is that most boards are using the TX & RX labeled pins for the default flashing/debugging UART of the ESP32. These pins will output debugging information and allow to flash the firmware.
The DroneBridge for ESP32 firmware is not configured to re-assign that UART. Your device will crash if you choose them anyways.
Note the GPIO numbers, board manufacturers often re-number their pins and the numbers do not match with the GPIO numbers!
To enable flow control you must wire two additional lines RTS and CTS. They cross over just like TX & RX. Any pin of the ESP32 (except for the TX & RX marked pins) can be used for RTS and CTS. Just choose one and make sure your board manufacturer did not connect it to the internal flash or USB port.
For the XIAO ESP32C3 board, this means: Do not choose D6 or D7.
