LTM not supported on Mateksys F405-STD?

Hi, thx for the great work of you all. I was impressed by the Arducopter functions and I decided to use it on my Mateksys F405-STD FC. I use MatekF405-STD v4.03 firmware. https://firmware.ardupilot.org/Copter/stable-4.0.3/MatekF405-STD

It all works wel, but I ran into the telemetry problem. I planned to use LTM telemetry on Serial1. In configured it like this:

SERIAL1_PROTOCOL 25
SERIAL1_OPTIONS 0
SERIAL1_BAUD 9600

I attached an FTDI-adapter to read the Serial1 port, but nothing is coming out. I attached an oscilloscope (I don’t have a logic analyser) and I don’t see a signal coming out.

I changed the SERIAL1_PROTOCOL to 1 (mavlink1) and I get data from the FTDI and I see a signal on the oscilloscope.

I have the same problem with Frsky Dport on Serial2 (SERIAL2_PROTOCOL 3).

What am I doing wrong or are the Telemetry protocols (except for mavlink) not supported?

Your response is highly appreciated. Thanks.

Mateksys F405-std serial definitions:

  • SERIAL0 = console = USB
  • SERIAL1 = Telemetry1 = USART3
  • SERIAL2 = Telemetry2 = UART4
  • SERIAL3 = GPS1 = USART1
  • SERIAL4 = GPS2 = UART5

I have matek 405 CTR and i connect this wifi telemetry on USART3 and works well

afaik you‘ll find LTM support in master only as for now.