Telemetry not working constant green lights - Solved

Hello everyone,
I send you this message because I have some problems with the telemetry I use on my drone (FC : Matek H743-Wing V3). I am using Mission planner and I have configured the SERIAL with the correct parameter (protocol + Baud rate)

Both modules (ground and air) have a constant green LED and are on version 2.2. However, I can’t communicate with the flight controller (I get a timeout after 30 seconds). Has anyone had a similar problem? Thanks a lot!
Nicolas

Make sure you don’t have the RX and TX lines crossed up on the FC.

Radio TX goes to FC RX, and vice versa.

Hi Yuri,
Already done but thanks ! I don’t really know what to do. Both radios are constant green + red lights blinking. I try to chang the baud rate for the USB connection but still not working.

You might switch those two wires around, just to rule out a silly mistake. It’s the most common cause of problems like this.

Otherwise, make sure that SERIALx_PROTOCOL=2, and SERIALx_BAUD is a valid value and matches what you have set in the radio (usually 57 or 115).

Double check the UART number to SERIALx mapping as well:

Default UART order

  • SERIAL0 = console = USB
  • SERIAL1 = Telemetry1 = UART7 (support CTS and RTS signaling)
  • SERIAL2 = Telemetry2 = USART1
  • SERIAL3 = GPS1 = USART2
  • SERIAL4 = GPS2 = USART3
  • SERIAL5 = USER = UART8
  • SERIAL6 = USER = UART4
  • SERIAL7 = USER = UART6 (TX only unless BRD_ALT_CONFIG = 1, then RX available also)

Hi yury thanks you a lot for your help !
I check everything you say and i don’t think i made a mistake there. I can add that when I connect the ground station to my computer via USB, it crashes mission planner/my computer sometimes.

Hi Yuri,
Thanks you very much ! I’ve found the problem in 2 steps :

  • Reinstall all drivers and set Baud Rate to 9600 on the USB port (and 57600 in MP).
  • Increase the distance betwenn the two modules

Why 9600? That seems to make no sense.

I have no idea but it seems to work. When i put 57600 on the USB port my PC crash and I can’t connect to MP with the device