Hi @umlr ,
Here's some info for VOXL 2 which shares most of the design.
https://docs.modalai.com/voxl2-linux-user-guide/#gpios
For the RB5, qualcomm had some sample code here:
https://github.com/quic/sample-apps-for-Qualcomm-Robotics-RB5-platform/tree/master/GPIO-samples
For example, we are using it here:
https://gitlab.com/voxl-public/voxl-sdk/utilities/voxl-bind/-/blob/master/src/voxl-bind.c#L58
GPIO 46 going to J10 pin 6.
GPIOs 82, 83 and 84 control the onboard LED which you can use and get visual feedback.