From 57d63b7362a8bd266b38f015de52b4a07a6d7714 Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Sun, 25 Jan 2026 17:45:08 +0100
Subject: [PATCH] ESPDMX robustness improvements

* clamp channel to dmxMaxChannel (write)
* ensure that all data get sent, including start byte
---
 wled00/src/dependencies/dmx/ESPDMX.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/wled00/src/dependencies/dmx/ESPDMX.cpp b/wled00/src/dependencies/dmx/ESPDMX.cpp
index 31adefdb..0ac3a5c7 100644
--- a/wled00/src/dependencies/dmx/ESPDMX.cpp
+++ b/wled00/src/dependencies/dmx/ESPDMX.cpp
@@ -73,6 +73,7 @@ void DMXESPSerial::write(int Channel, uint8_t value) {
 
   if (Channel < 1) Channel = 1;
   if (Channel > channelSize) Channel = channelSize;
+  if (Channel > dmxMaxChannel) Channel = dmxMaxChannel; // WLEDMM protect against array bounds violation
   if (value < 0) value = 0;
   if (value > 255) value = 255;
 
@@ -99,7 +100,7 @@ void DMXESPSerial::update() {
   //send data
   Serial1.begin(DMXSPEED, DMXFORMAT);
   digitalWrite(sendPin, LOW);
-  Serial1.write(dmxDataStore, channelSize);
+  Serial1.write(dmxDataStore, min(dmxMaxChannel+1, channelSize+1));
   Serial1.flush();
   delay(1);
   Serial1.end();