@saegsali BTW, the voxl_i2c commands are only going to try to exercise apps processor mapped i2c buses, not the DSP mapped ones on J19. Stick with the PX4 commands, those should work. And when you start PX4 from the command line use the -d option so that it doesn't start in daemon mode. E.g. MINIMAL_PX4=1 voxl-px4 -d.