Head tracking does not work with GM3

[mazi14]

Several people including me are complaining, that we are not able to get working head tracking of GM3 gimbal controlled by FC UART. There are several "Issues" here related to this topic, but all have been already closed and nobody answers, so I am trying new one.

My HW is Avatar Goggles X with extension module, GM3 gimbal and SpeedyBee F405 wing mini FC. I started experiment with gimbal using iNav 8.0.1 I updated all my HW to the latest FW (Goggles and VTx V2 39.44.5, gimbal V3.6 and extension module V2.2). Head tracking works fine when gimbal is connected directly to the VTx. But when I tried to connect gimbal and HT to the FC by single UART, head tracking does not work. Other gimbal modes work fine though. I tried downgrade HT and gimbal FW, but nothing has changed. I tried iNav 8.0.0 and 9.0.0 too with the same result. Is there really a bug in iNav or am I doing something wrong?

There are few things I am not sure about. I guess, I have to set HT in iNav as "serial" for my HW, right? When I enable single UART port (gimbal_serial_single_uart = ON), should I assign this UART to "serial gimbal" in "Port tab", although it is shared with HT too? This is the only option, which gives me control over the gimbal modes. I tried to change it to "serial headtracker", but I lost gimbal control then. And the last thing is, which VTx pin is the Tx one (which should I connect to FC Rx)? My understanding is that it is the one completely on the side. I tried the next one too of course.

And does anyhow GimbalConfig settings (channel mapping, preset mode, sensitivity and roll/pitch/yaw angle introduced in V3.6) affect iNav?

[wilco1967]

From what I've tried, Gimbal control from iNav UART only works with Gimbal firmware upto 3.4
Gimbal V3.4 works fine also with Inav 9.0.0

V3.6 and V3.8 don't work (at least with iNav 8.x). Didn't try newer gimbal firmware again with iNav 9.0.0.

Seems like something got broken between gimbal version 3.4 and newer

There is nothing wrong with V3.4 as far as I can tell. Does everything it needs to do....

[mazi14]

Thank you for your findings. Are you talking about "gimbal control" or "head tracking". They are 2 different things. For me, gimbal control works, but head tracking not. I have already tried gimbal FW 3.4 without succes. It looks like that it is related with goggles and VTx FW too. Which one are you using? I updated to 39.44.5 and was not able to downgrade. During this night it reminded me that I have to rename old FW, otherwise I got message "NO UPDATE".

[wilco1967]

Thank you for your findings. Are you talking about "gimbal control" or "head tracking". They are 2 different things. For me, gimbal control works, but head tracking not. I have already tried gimbal FW 3.4 without succes. It looks like that it is related with goggles and VTx FW too. Which one are you using? I updated to 39.44.5 and was not able to downgrade. During this night it reminded me that I have to rename old FW, otherwise I got message "NO UPDATE".

I'm talking about gimbal control from iNav UART to GM3.
Walksnail doesn't come into play with that.
Never tried the walksnail route for headtracking. neither direct, or via iNav

I only have the very first Walksnail goggles without the headtracking.

I do have a small external headtracking device, taped onto the goggles, but that works via bluetooth to EdgeTX, and then via a few radio channels to the FC, and on to the GM3. That works just fine. But usually, I just use some of the knobs on the radio to pan/tilt the camera (as moving my head points the antenna's of the goggles away from the model, which becomes an issue at long range.

But when I tried to connect gimbal and HT to the FC by single UART, head tracking does not work. Other gimbal modes work fine though

Are you saying, GM3 control works fine, even with version gimbal V3.6 via the FC, as long as you don't try to share the Uart with walksnail/headtracker ? Never got anything unless downgrade to V3.4.

[dzaro-dev]

Are you saying, GM3 control works fine, even with version gimbal V3.6 via the FC, as long as you don't try to share the Uart with walksnail/headtracker ? Never got anything unless downgrade to V3.4.

@wilco1967 Can you please share the V3.4 firmware so that I can do some testing with it?

[wilco1967]

@wilco1967 Can you please share the V3.4 firmware so that I can do some testing with it?

seems it is no longer on Caddx Website....
anyway, here is a copy...

https://drive.google.com/file/d/1XQlZfS0njG39wonO23L4LS5zWxgH78wZ/view?usp=drive_link