SIYI FPV app - MavLink OSD


I need help getting MavLink OSD to work with the SIYI FPV app.

I’ve installed my SIYI A8 camera/gimbal and have had some good success with it using the SIYI QGC app.

I’m using a HereLink V1.1 and the A8 is connected to the HereLink Air Unit with ethernet.

I would now like to try using the SIYI FPV app - which looks like an excellent alternative to QGC.

The SIYI FPV app supports OSD data for basic telemetry. I need help getting this function to work.

Reading the SIYI A8 manual, there is nothing about how to get the MavLink telemetry messages to the A8.

On a hunch, I connected the A8’s UART to Serial4 on my carrier board, and configured it as MavLink and baud of 115200. I tried both MavLink 1 and MavLink 2. Connection info was taken from this doc in the ArduPilot wiki:

SIYI ZR10, ZR30 and A8 Gimbals — Copter documentation

I’ve installed standard UART TX/RX/GND cabling from the carrier board to the A8:

Perhaps the A8 cannot receive this telemetry data this way. By copy to @SIYI could you please find out if this is possible - and how to do it?

Thank you.

Looking at the SIYI documentation again, it appears my idea of connecting telemetry from the autopilot to the gimbal is wrong.

In the SIYI documentation, which is geared towards SIYI control radios, it appears that telemetry on SIYI control radios is similar to how it’s done on the HereLink. That is there’s a serial telemetry connection from the autopilot to the SIYI control radio Air Unit.

The SIYI custom Qgroundcontrol app is able to extract the telemetry data from the HereLink ground unit, and make it available to the app.

I’m guessing now that the SIYI FLY app is designed to work the same way - but for some reason cannot get access to the telemetry data stream on the HereLink.

Perhaps there’s a configuration change on HereLink that’s required for the SIYI FLY app to get the telemetry data stream.