PX4FMU Standalone

I have a PX4FMU v1.7 that I would like to operate without a PX4IO board. Is there a version of firmware that allows me to do this? The standard releases seem to expect a PX4IO and just lock up.


Try setting the param SYS_USE_IO to 0.

You’ll likely have to work through a few more issues, but it depends what you’re trying to do.

@dagar How does SYS_USE_IO get set to zero for the fmu-v4 target? I would think it should be zero for all fmu-v1 builds too.

It’s USE_IO within the init script that starts and updates the px4io. You can see the hardware checks above which disable it even if SYS_USE_IO 1.

wow, thanks… I didn’t even think to look for it in rcS. Seems like it should be overridden for fmu-v1 also

Setting SYS_USE_IO to zero seems to help. I’m able to get the PX4FMU connected to QGC now and successfully calibrated the radio over PPM with SYS_Autostart: 4008.

I’m now stuck on calibrating the ESC’s which fails with a message of “Unable to disable safety switch”. I don’t think I have a safety switch without an IO board. I see the ecs_calibration code is making calls into px4_ioctl that may be failing.