Thank you Dave84 four your answer.
1 : [https://www.expresslrs.org/quick-start/receivers/wiring-up/](Receiver Wiring - ExpressLRS)
Connect your receiver to any free UART on your Flight controller. Check your Flight Controller Wiring Manual which UARTs you can use.
- The GND or G pad should be connected to any Ground pad on the Flight Controller(FC)
- The VCC or 5 pad should be connected to any 5v (or 4v5) pad on the Flight Controller(FC)
- The TX or T pad should be connected to an RX pad of the same UART number where the RX or R wire is on the Flight Controller(FC)
- The RX or R pad should be connected to a TX pad of the same UART number where the TX or T wire is on the Flight Controller(FC)
I use TELEM 3 on Pixhawk 6x/
I used:
PIN 1 : Red (+5V)
PIN 2: Black: TX7/5/2 (out)_ +3.3V
PIN 3: Black: ___RX7/5/2 (in) ____+3.3V
PIN 6: Black:____GND___________GND
2
In the configuration of the serial port select the RCIN protocol. So for example for serial port 4:
- Set SERIAL4_PROTOCOL = 23
- Set RSSI_TYPE = 3
Note: The serial port baudrate is automatically set and controlled by the firmware when any serial RC protocol, such as CRSF, is detected.
In https://ardupilot.org/plane/docs/common-holybro-pixhawk6X.html#compass
After, I do this:
- Set SERIAL5_PROTOCOL=23
- Set RSSI_TYPE=3
And all will be ok