Chan 3 to 9, PWM: failed, no DMA

ArduCopter
1

I have a Flight Controller F405-WMN.
Flashed Arducopter 4.5.5. With dshot.
From:
https://firmware.ardupilot.org/Copter/stable-4.5.5/MatekF405-TE-bdshot/

I get this error message:
Chan 3 to 9, PWM: failed, no DMA
And motors (DSHOT) do not respond.

Please advise.

2

On that board, you need to use outputs 1, 4, 6, and 7 for BDSHOT.

Can be seen here in the hwdef:

PC9  TIM8_CH4   TIM8  PWM(1)  GPIO(50) BIDIR
PC8  TIM8_CH3   TIM8  PWM(2)  GPIO(51)
PB15 TIM12_CH2  TIM12 PWM(3)  GPIO(52) NODMA
PA8  TIM1_CH1   TIM1  PWM(4)  GPIO(53) BIDIR
PB11 TIM2_CH4   TIM2  PWM(5)  GPIO(54)
PB10 TIM2_CH3   TIM2  PWM(6)  GPIO(55) BIDIR
PB3  TIM2_CH2   TIM2  PWM(7)  GPIO(56) BIDIR
PA15 TIM2_CH1   TIM2  PWM(8)  GPIO(57)
3

Thanks!

If I don’t want to do bidirectional dshot (bdshot), can I ignore the DMA warnings and use PWM 3,4,5,6 for “normal” dshot (without bidrectional)?

4

Not with that message present.

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