AEDROXH7: fix LED strip DMA conflict with motor outputs#11629
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sensei-hacker merged 1 commit intoJun 7, 2026
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dmavar=0 maps to DMA1 Stream 0, which is already claimed by M1 (TIM8_CH2). When DSHOT is active, the LED strip silently fails to initialize because its DMA stream is already owned. Change to dmavar=8 (DMA2 Stream 0), matching the pattern used by other H7 targets (MATEKH743, MAMBAH743, etc.).
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Test firmware build ready — commit Download firmware for PR #11629 1 targets built. Find your board's
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Problem
The LED strip entry in
target.cuseddmavar=0:On STM32H7,
dmavaris a flat index into a 16-entry list of all DMA streams (DMA1 S0–S7 at indices 0–7, DMA2 S0–S7 at indices 8–15). Index0selects DMA1 Stream 0, which is already claimed by M1 (TIM8_CH2, alsodmavar=0).When DSHOT is active, motor DMA streams are allocated before the LED strip initialises. By the time
ws2811LedStripInit()runs, DMA1 S0 is already owned, causingledConfigureDMA()to silently returnfalse— the LED strip never initialises.This explains why the issue was not caught during initial testing: if tested without DSHOT active, DMA1 S0 is still free when the LED strip initialises and everything appears to work.
Fix
Change
dmavarfrom0to8(DMA2 Stream 0), moving the LED strip off the motor DMA bank:This matches the pattern used by other H7 targets (MATEKH743, MAMBAH743, FOXEERH743, BROTHERHOBBYH743 all use
dmavar=8or9for their LED strip entries).Testing
Verified on hardware with DSHOT active — LED strip operates correctly after this fix.