CPPM receiver with BigQuad deck on the Roadrunner

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matejkarasek
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CPPM receiver with BigQuad deck on the Roadrunner

Post by matejkarasek » Wed Jul 10, 2019 4:02 pm

Hi,

I have a Roadrunner board with the BigQuad deck, and have managed to hook up a servo that I can actuate via PWM, using the Android Crazyflie Client app.
I have also connected a CPPM receiver, but no idea how to get that working. I would like to use CPPM signals as the main controller.

Does anyone have experience with that?

Thanks,
Matej



tobias
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Re: CPPM receiver with BigQuad deck on the Roadrunner

Post by tobias » Thu Jul 18, 2019 9:18 am

Unfortunately the CPPM input does not work at the same time as the Loco deck which is integrated to the Roadrunner. It might be possible to move the CPPM to another available TIMER and PIN but that requires some investigation and coding work. Also to have the Loco deck work with the BQ-deck have you checked this?

matejkarasek
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Re: CPPM receiver with BigQuad deck on the Roadrunner

Post by matejkarasek » Thu Jul 25, 2019 8:57 am

Hi Tobias,

Thanks for your reply, only replying now as my notifications were not set up correctly...

I have made the software and hardware changes as described under your link (only the first part as I don't plan to use the flow deck).

I won't need the CPPM and the (integrated) Loco deck working at the same time (at least at the beginning). Is it possible to disable the Loco deck for now (I suppose this would require hardware change to get CPPM working)?

Is there some example how to set up CPPM with a BigQuad deck on the crazyflie board?

Thanks!
Matej

tobias
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Location: Sweden

Re: CPPM receiver with BigQuad deck on the Roadrunner

Post by tobias » Tue Aug 06, 2019 2:20 pm

The loco deck would need a FW were it is disabled. In the tag.mk comment out the bcDWM1000 line

Code: Select all

#CFLAGS += -DDECK_FORCE=bcDWM1000
Then rebuild the tag FW and flash it.

Code: Select all

make PLATFORM=tag
In the tag.mk file you have probably added build flags for the BigQuad deck right so you know how to do this?

As for the CPPM there is no good documentation and it's been a while since I used it myself so you might have to play around a bit. The configuration for the channels etc can be found in extrx.c. This defines you might have to change or configure accordingly in your transmitter so the mapping is correct. Other then that the extrx input has priority, so as soon as a signal is received, it should start working. A good way to debug would be to look at the extrx log variables.

matejkarasek
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Joined: Tue Jul 09, 2019 11:50 am

Re: CPPM receiver with BigQuad deck on the Roadrunner

Post by matejkarasek » Tue Aug 06, 2019 9:25 pm

Thanks, Tobias, got it working following your instructions!
Obviously (although not obvious to me at first) I also needed to uncomment the previously commented lines as described here

Thrust still behaves a bit strange, will look at that tomorrow...

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