Stinger control via mavlink joystick

qubotics-admin

Hi.

We have the stinger drone and would like to fly it using the UXV SRoC controller (joystick). We have done the following modifications:

removed the VTX and plugged in a doodlelabs radio in its place.
removed the ELRS receiver and plugged in the VOXL IO expander board (to get PWM for the IR/visual lights).
Connected the Lights signal wire to the IO expander.
In software, we:
a. stopped the vtx service, and configured the doodlelabs radio
b. configured the voxl-streamer to stream the fpv camera
b. in px4 config file, set RC = EXTERNAL (to support joystick)
c. in px4 start, set "qshell voxl2_io start -p 7 #(use QUP7)" to start voxl io on that port
We get telemetry and video on QGC. In the "Actuators" tab, we are able to control the motors and the lights.
We get mode switch and arming to work by mapping actions to buttons for joystick.

Where we got stuck is using joystick to control the Lights, turtle mode, and camera switching. Can you pls suggest how we can control these functionality with joystick? I see that the voxl-px4 service is using an older px4 firmware that publishes a basic manual_control_setpoint message when "manual_control" messages are received from the gcs.

Eric Katzfey

@qubotics-admin The joystick button to use for turtle mode is set via the VOXL_ESC_T_ON parameter.

qubotics-admin

@Eric-Katzfey I tried that parameter, but I did was not able to get the motors to spin in turtle mode.
I tried searching the voxl-px4 repo and could not find how that parameter is used. Do you mind sharing some insight on how the joystick button will trigger turtle mode?
Just to highlight that I am not using a VTX but doodlelabs radio to connect to a handheld gcs/joystick.

Eric Katzfey

@qubotics-admin It's in the voxl-fpv-dev branch of our px4 fork. See https://github.com/modalai/px4-firmware/blob/7e1625f20fac5f44a0034bebdb1e3d4027124684/src/modules/mavlink/mavlink_receiver.cpp#L108

qubotics-admin

@Eric-Katzfey thank you for pointing me to that. It is really helpful!

Two more questions:
1- is there a way to know the git commit for the voxl-px4 on the drone at the moment?
2- how lights are operated on the stinger? is there a direct passthrough from RC to the outputs (P0,P1,P2,P3) on the ELRS receiver? If not, where in the voxl-px4 code does the Lights pwm get assigned pls?

Thanks for your support!

Eric Katzfey

@qubotics-admin First you need to determine the version of PX4 running. With ssh or adb you can run the following at the command line: px4-ver all. You will see PX4 version and Vendor version. So, for example, for px4 version 1.14.0 and vendor version 8.134.3 then you would checkout the tag v1.14.0-8.134.3-dev from the repo to see that commit.