DMX improvements and configuration option.

wled00/cfg.cpp

@@ -734,6 +734,7 @@ bool deserializeConfig(JsonObject doc, bool fromFS) {
   CJSON(DMXGap,dmx[F("gap")]);
   CJSON(DMXStart, dmx["start"]);
   CJSON(DMXStartLED,dmx[F("start-led")]);
+  CJSON(DMXNumFixtures, dmx[F("num-fixtures")]);
 
   JsonArray dmx_fixmap = dmx[F("fixmap")];
   for (int i = 0; i < dmx_fixmap.size(); i++) {
@@ -1235,6 +1236,7 @@ void serializeConfig(JsonObject root) {
   dmx[F("gap")] = DMXGap;
   dmx["start"] = DMXStart;
   dmx[F("start-led")] = DMXStartLED;
+  dmx[F("num-fixtures")] = DMXNumFixtures;
 
   JsonArray dmx_fixmap = dmx.createNestedArray(F("fixmap"));
   for (unsigned i = 0; i < 15; i++) {

wled00/data/settings_dmx.htm

@@ -57,14 +57,14 @@ <h2>Imma firin ma lazer (if it has DMX support)</h2><!-- TODO: Change to somethi
 
 Proxy Universe <input name=PU type=number min=0 max=63999 required> from E1.31 to DMX (0=disabled)<br>
 <i>This will disable the LED data output to DMX configurable below</i><br><br>
-<i>Number of fixtures is taken from LED config page</i><br>
 
 Channels per fixture (15 max): <input type="number" min="1" max="15" name="CN" maxlength="2" onchange="mMap();"><br />
 Start channel: <input type="number" min="1" max="512" name="CS" maxlength="2"><br />
 Spacing between start channels: <input type="number" min="1" max="512" name="CG" maxlength="2" onchange="mMap();"> [ <a href="javascript:alert('if set to 10, first fixture will start at 10,\nsecond will start at 20 etc.\nRegardless of the channel count.\nMakes memorizing channel numbers easier.');">info</a> ]<br>
 <div id="gapwarning" style="color: orange; display: none;">WARNING: Channel gap is lower than channels per fixture.<br />This will cause overlap.</div>
 <button type="button" onclick="location.href='/dmxmap';">DMX Map</button><br>
-DMX fixtures start LED: <input type="number" min="0" max="1500" name="SL">
+DMX fixtures start LED: <input type="number" min="0" max="1500" name="SL"><br>
+Number of fixtures: <input type="number" min="1" max="512" name="NF">
 <h3>Channel functions</h3>
 <div id="dmxchannels"></div>
 <hr><button type="button" onclick="B()">Back</button><button type="submit">Save</button>

wled00/dmx_output.cpp

@@ -12,12 +12,37 @@
 
 #ifdef WLED_ENABLE_DMX
 
+#define MAX_DMX_RATE 44 // max DMX update rate in Hz
+
 void handleDMXOutput()
 {
   // don't act, when in DMX Proxy mode
   if (e131ProxyUniverse != 0) return;
 
+  // Ensure segments exist before accessing strip data
+  if (strip.getSegmentsNum() == 0) return;
+
+  // Rate limiting
+  static unsigned long last_dmx_time = 0;
+  const unsigned long dmxFrameTime = 1000 / MAX_DMX_RATE;
+  if (millis() - last_dmx_time < dmxFrameTime) return;
+
   uint8_t brightness = strip.getBrightness();
+
+  // Track last brightness sent to DMX, allow one final update when brightness becomes 0
+  static uint8_t lastSentBrightness = 255;
+
+  // Skip DMX entirely if strip is off
+  if (brightness == 0 && lastSentBrightness == 0) return;
+
+  // Change detection: only update if strip data has changed since last update
+  static unsigned long lastStripShow = 0;
+  unsigned long currentShow = strip.getLastShow();
+  if (currentShow == lastStripShow && brightness == strip.getBrightness() && brightness != 0) {
+    return;
+  }
+  lastStripShow = currentShow;
+  last_dmx_time = millis();
 
   bool calc_brightness = true;
 
@@ -28,9 +53,15 @@ void handleDMXOutput()
    }
 
   uint16_t len = strip.getLengthTotal();
-  for (int i = DMXStartLED; i < len; i++) {        // uses the amount of LEDs as fixture count
-
-    uint32_t in = strip.getPixelColor(i);     // get the colors for the individual fixtures as suggested by Aircoookie in issue #462
+  if (len == 0) return;
+
+  // OPTIMIZATION: Only process the LEDs that actually need DMX output
+  // Limit to configured number of fixtures instead of processing all LEDs
+  uint16_t dmxEndLED = DMXStartLED + DMXNumFixtures;
+  if (dmxEndLED > len) dmxEndLED = len;
+
+  for (int i = DMXStartLED; i < dmxEndLED; i++) {
+    uint32_t in = strip.getPixelColor(i);
     byte w = W(in);
     byte r = R(in);
     byte g = G(in);
@@ -66,6 +97,7 @@ void handleDMXOutput()
   }
 
   dmx.update();        // update the DMX bus
+  lastSentBrightness = brightness;
 }
 
 void initDMXOutput() {

wled00/set.cpp

@@ -640,6 +640,10 @@ void handleSettingsSet(AsyncWebServerRequest *request, byte subPage)
     if (t>=0 && t < MAX_LEDS) {
       DMXStartLED = t;
     }
+    t = request->arg(F("NF")).toInt();
+    if (t>0 && t<=512) {
+      DMXNumFixtures = t;
+    }
     for (int i=0; i<15; i++) {
       String argname = "CH" + String((i+1));
       t = request->arg(argname).toInt();

wled00/src/dependencies/dmx/SparkFunDMX.cpp

@@ -139,19 +139,18 @@ void SparkFunDMX::write(int Channel, uint8_t value) {
 void SparkFunDMX::update() {
   if (_READWRITE == _WRITE)
   {
-    //Send DMX break
+    // Manually create DMX break signal, is more efficient than using Serial settings
+    // Break is just a high signal for minimum 88us, then low (mark) for 8us
+    pinMode(txPin, OUTPUT);
     digitalWrite(txPin, HIGH);
-    DMXSerial.begin(BREAKSPEED, BREAKFORMAT, rxPin, txPin);//Begin the Serial port
-    DMXSerial.write(0);
-    DMXSerial.flush();
-    delay(1);
-    DMXSerial.end();
+    delayMicroseconds(176); // Break duration (176us is standard, 88us minimum)
+    digitalWrite(txPin, LOW);
+    delayMicroseconds(8);
 
-    //Send DMX data
-    DMXSerial.begin(DMXSPEED, DMXFORMAT, rxPin, txPin);//Begin the Serial port
+    // Re-enable serial and send data
+    DMXSerial.begin(DMXSPEED, DMXFORMAT, rxPin, txPin);
     DMXSerial.write(dmxData, chanSize);
-    DMXSerial.flush();
-    DMXSerial.end();//clear our DMX array, end the Hardware Serial port
+    DMXSerial.end();
   }
 #if !defined(DMX_SEND_ONLY)
   else if (_READWRITE == _READ)//In a perfect world, this function ends serial communication upon packet completion and attaches RX to a CHANGE interrupt so the start code can be read again

wled00/xml.cpp

@@ -636,6 +636,7 @@ void getSettingsJS(byte subPage, Print& settingsScript)
     printSetFormValue(settingsScript,PSTR("CG"),DMXGap);
     printSetFormValue(settingsScript,PSTR("CS"),DMXStart);
     printSetFormValue(settingsScript,PSTR("SL"),DMXStartLED);
+    printSetFormValue(settingsScript,PSTR("NF"),DMXNumFixtures);
 
     printSetFormIndex(settingsScript,PSTR("CH1"),DMXFixtureMap[0]);
     printSetFormIndex(settingsScript,PSTR("CH2"),DMXFixtureMap[1]);