RC_Channel and RCInput produce no output with MatekH743 and mRoX21

First, I should mention that ArduCopter works fine with both the MatekH743 and mRoX21. I should also mention that other examples compile, deploy and run fine - with RC working as one would expect.

However, I’m having trouble getting the RC-related examples (RC_Channel and RCInput) to work. I receive either no output at all, output showing zero channel activity, or just zero channels. No joy with either the MatekH743 and mRoX21. I don’t have any other board to try them with.

Are these examples up to date? Do they work fine for other people?

Good day, im using mro x2.1 red board and also the mRo x2.1 777 without any issue.
Did you check the correct pinout from the x2.1 fc pins to the receiver?

Hi. Yes. As I mentioned, it works fine with ArduCopter. It’s the RC-related examples that don’t work.

From where does the RCInput example set its configurable values? I.e. for things like SBUS input (in my case).

You must connect the receiver following these pins SIPI-VCC-GND…, just check also the correct wiring on the receiver.
Just be sure also you have bind your receiver with the rc

Yes, like I said, ArduCopter works, so it is connected properly. It is the example code that doesn’t work. Is there no software config necessary for the example code? Because that’s the only thing it can be…

What do you mean for example code?

The example code: https://ardupilot.org/dev/docs/learning-ardupilot-rc-input-output.html

you must modify the code and compile the firmware with the modification you have done…, i don’t have experience about modify the code… sorry

The code should not need modification. Building it is fine, as I have already mentioned. Deploying it is fine, as I have already mentioned.

Unfortunately, I still cannot get the RC_Channel example to work. The following param ensures that SBUS is selected, which is correct for my case:

Like I said, the RC portion of Arducopter itself (i.e. the full program) works fine, which is very odd. I have no idea why the example doesn’t. I have had no problem getting the non-RC-related examples working.

Hey Pogo

I encountered your exact same problem. Not on Matek or mRoX21, but in the CubeBlack and also on Pixhawk 2.4.8, and also not with Sbus, but with normal PPM signal.

The case I have is like this:

  1. If I upload Arducopter, with my RC PPM signal connected, everything works fine. I can see the signals as I move them.

  2. If I run RCInput, RC_Channel, RCInputToRCOuput examples, the codes compile correctly as they are, and run when my transmitter (the one with the joysticks) is off. However, when I turn it on, it completely stops spitting out anything on the serial, and basically freezes the serial port entirely. I have to actually disconnect and connect it back so that is does something reasonable. After this, again, I can upload normal arducopter and see the signals perfectly, but the examples don’t run.

I would really like some help with this.


Hello, I have the same problem today, did you find an issue of this problem ? Thank you for your help.