Remove SYS_USE_IO param

[julianoes]

The param is not really required anymore with the actuator configuration. Also, when it is set to 0, RC doesn't work for some boards which would be nice to avoid.

If you have alternative ways to fix #22206, that's fine with me, but as it is now, the param description is a lie and this is a major regression with v1.14.

Fixes #22206

Needs to go into v1.14.

[dagar]

This is fine from my perspective because if someone doesn't want to use px4io outputs they can simply not configure them now. As for RC ORB_ID(input_rc) will only be published if anything is found (CRSF and soon other protocols could still be explicitly enabled and used FMU side regardless).

Beyond that if someone has a board with a px4io and they really don't want it used at all they can simply disable it in their build, I don't think this needs to be a user accessible runtime feature.

Can anyone think of another case where it matters?

[dagar]

Hold on, this might still be a minor issue for fmu-v5 (pixhawk 4 vs 4 mini) and some other PAB cases.

For example we need to make sure the pixhawk 4 mini still boots cleanly without errors.

[julianoes]

Can we merge this? And get it into v1.14.1?

[julianoes]

Alright, no more comments, merging. Otherwise it rots I get told off for not merging early enough.

[AlexKlimaj]

How does this interact on carrier boards with the RC input using the IO UART?

[julianoes]

@AlexKlimaj this basically means IO is always started, and so RC should always work. The problem was that the param let us disable IO which lead to RC not working. Does that make sense?

[AlexKlimaj]

@AlexKlimaj this basically means IO is always started, and so RC should always work. The problem was that the param let us disable IO which lead to RC not working. Does that make sense?

No I mean on carrier boards without an IO processor like the ARK PAB Carrier. USART6 goes to the RC connector instead of the IO MCU.

[julianoes]

My guess is they should work fine but we should test it.

[mcsauder]

Glad you merged it. Thank you.

[AlexKlimaj]

ERROR [px4io] PX4IO Not Supported
INFO  [tune_control] Stopping playback...
ERROR [px4io] PX4IO Not Supported
PX4IO start failed

I am getting a constant error tune playing without a PX4IO carrier board.

[AlexKlimaj]

Maybe RCS should query the manifest to check if the PX4IO is expected to be present before attempting to upgrade firmware or start the driver.

https://github.com/PX4/PX4-Autopilot/blob/main/src/drivers/px4io/px4io.cpp#L1763

[bresch]

@julianoes My Pixhawk4 mini does a continuous SOS beep because of this.

[julianoes]

Is there a way to know whether it is a Pixhawk 4 or 4 mini? @bresch can you share the boot output and ver all?

[AlexKlimaj]

@bresch @julianoes see #22368