AP_Periph CAN node cannot output neopixel(ws2812) signal

Hardware CAN Devices
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1

I have a MatekH743 and a Matek-L431-Periph, with the following parameters set:

MatekH743:

  • CAN_D1_PROTOCOL=1
  • CAN_P1_DRIVER=1
  • NTF_LED_OVERRIDE=0
  • NTF_LED_TYPES=289

Matek-L431-Periph:

  • NTF_LED_LEN=1
  • NTF_LED_OVERRIDE=1
  • NTF_LED_TYPE=256
  • OUT5_FUNCTION=120

The H743’s firmware is ArduCopter-4.5.7 and L431’s firmware is 1.8.0.

But, the WS2812 connected to L431 is never on. I can see the node in Mission Planner’s DroneCAN panel, and the GPS connected to L431 works well.

I also stick a oscilloscope to PWM 5 pin of the L431, and can only see a straight line.

I tried to set OUT8_FUNCTION=120 on the H743, and H743’s PWM 8 can output the right signal.

Did I do anything wrong?

2

You can check this URL: https://firmware.ardupilot.org/AP_Periph/stable/MatekL431-Periph/features.txt, and you will see that the MatekL431-Periph does not support controlling WS2812.

Screenshot 2025-06-25 at 16-02-37
Screenshot 2025-06-25 at 16-02-37348×377 6.67 KB

3

Thank you. I’ve figured out that since commit e736d5ecb78bb6a5, NEOPIXEL is not supported by default. But Matek still has this feature listed on their website https://www.mateksys.com/?portfolio=can-l431#tab-id-3 .

I’ve created a PR so that this issue will be fixed. See AP_HAL_ChibiOS: fix NeoPixel support for MatekL431-Periph by villivateur · Pull Request #30469 · ArduPilot/ardupilot · GitHub