Jan/WLED_MM_Infinity
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protect start byte

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If Channel is less than 0, it's clamped to 0 on line 134. Then on line 138, dmxData[0] is written with the value, overwriting the start byte that was just set on line 137. DMX Channel numbers should be 1-based (1-512). The bounds check should clamp Channel to a minimum of 1, not 0, to prevent corrupting the start byte

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
This commit is contained in:
Frank Möhle
2026-01-25 17:29:10 +01:00
committed by GitHub
parent 3150f3b448
commit e6e2348483
1 changed files with 1 additions and 1 deletions
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wled00/src/dependencies/dmx/SparkFunDMX.cpp
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@@ -131,7 +131,7 @@ uint8_t SparkFunDMX::read(int Channel) {
// Function to send DMX data
void SparkFunDMX::write(int Channel, uint8_t value) {
if (Channel < 0) Channel = 0;
if (Channel < 1) Channel = 1;
if (Channel+1 > chanSize) chanSize = min(dmxMaxChannel +1, Channel+1); // WLEDMM "+1" as we need to account for start byte
if (Channel > dmxMaxChannel) Channel = dmxMaxChannel; // WLEDMM prevent array out-of-bounds access
dmxData[0] = 0;