S5 output on MATEK 722-SE does not work in DSHOT #4924
In DSHOT mode (all speeds) S5 output on MATEK 722-SE does not operate correctly, there is no motor control, neither any ESC beeps to confirm correct startup. Tested with different ESC and cable connections to be sure. In STANDARD mode (PWM) all is OK. Other outputs (S1-S4, S6) are OK.
Steps to Reproduce
MATEK 722-SE flight controller flashed with most recent stable INAV (2.2.1)
I would expect DSHOT control on all outputs S1-S6 on the controller.
It seems this issue was somehow foreseen as if You check the sources, https://github.com/iNavFlight/inav/blob/2.2.1/src/main/target/MATEKF722SE/target.c on line 37 mentions something that S5 is in a clash with S2. I guess this could be addressed by different DMA settings, but I lack the STM32 experience to take the next step. But happy to follow a suggestion, test and make a pull request if I fix it.
Dump link: https://pastebin.com/54idtVh8
This is hardware limitation and there are no other option for DMA selection.
S2 - the only possibility is TIM3_CH2, DMA 1, stream 5, channel 5
To make DSHOT work DMA/Stream should be unique for all channels, therefore there is no possibility to have more than 4 channels DSHOT on this FC.