marian-vittek / raspberry-pi-dshot Goto Github PK

This project allows to generate DSHOT protocol to control ESCs via the
GPIO pins of a Raspberry Pi.  It was developed and used on Raspberry
Pi Zero 2, but should work on any Raspberry Pi 1/2/3/4.  It does not
work with Raspberry Pi 5. We have a more sophisticated implementation
with less CPU consumption at
https://github.com/Marian-Vittek/raspberry-pi-dshot-smi .

This implementation uses busy wait and 'clock_gettime' for timing and handles DSHOT 150
protocol well. It is running on standard Raspbian OS, no RT extension is
required. However, it may help if you use some hacks from
https://forums.raspberrypi.com/viewtopic.php?t=245561&sid=d3b2f6139ccf00a88aa7a98db2aed7f3
to reduce interrupts on a specific core.

This code is inspired by
https://github.com/dmrlawson/raspberrypi-dshot. Compared to it this
version:

- uses "clock_gettime" instead of an empty loop.
- allows multiple frames to be sent to multiple pins at once.

To compile and run a simple test that spins 4 motors connected to GPIO
16, 19, 20 and 21, type

    	   make test
	   sudo chrt -f 99 ./test 16 19 20 21

If it does not work you may need to edit 'motor-dshot.c' and adjust
DSHOT_BIT_ns and/or DSHOT_T0H_ns macro.