configurable GRB/RGB LEDs per LED

CLAUDE.md

@@ -58,7 +58,7 @@ The sketch controls `GAUGE_COUNT` stepper-motor gauges using a trapezoidal veloc
 
 ### Key data structures
 
-- `GaugePins` — hardware pin mapping per gauge (dir, step, enable, active-high/low polarity flags, `ledCount`). Declared `constexpr` so `TOTAL_LEDS` can be computed from it at compile time. Configured in the `gaugePins[]` array at the top.
+- `GaugePins` — hardware pin mapping per gauge (dir, step, enable, active-high/low polarity flags, `ledOrder` string). Declared `constexpr` so `TOTAL_LEDS` can be computed from it at compile time. Configured in the `gaugePins[]` array at the top.
 - `Gauge` — per-gauge runtime state: position, target, velocity, accel, homing state machine, sweep mode.
 
 ### Motion control (`updateGauge`)
@@ -76,7 +76,7 @@ When `sweepEnabled`, `updateSweepTarget` bounces `targetPos` between `minPos` an
 
 ### LED strip
 
-One shared WS2812B strip is driven from `LED_DATA_PIN` (currently 22). Each gauge owns a contiguous segment of the strip; `gaugePins[i].ledCount` sets the segment length (0 = no LEDs). `TOTAL_LEDS` is computed at compile time via `constexpr sumLedCounts()` — no manual constant to keep in sync. Per-gauge offsets into the flat `leds[]` array are computed once in `setup()` into `gaugeLedOffset[]`. LED commands and effects mark the strip dirty, and `FastLED.show()` is called once per main-loop iteration if anything changed.
+One shared WS2812B strip is driven from `LED_DATA_PIN` (currently 22). Each gauge owns a contiguous segment of the strip; `gaugePins[i].ledOrder` is a per-LED type string (one char per LED, `'G'` = GRB-ordered, `'R'` = RGB-ordered) and its length defines the segment length (empty string = no LEDs). `TOTAL_LEDS` is computed at compile time via `constexpr sumLedCounts()` — no manual constant to keep in sync. Per-gauge offsets and counts are cached in `setup()` into `gaugeLedOffset[]` and `gaugeLedCount[]`. The strip is initialised as `GRB`; writes to RGB-ordered LEDs are R/G-swapped via the `writeLed`/`readLed` helpers so callers always work in logical RGB. LED commands and effects mark the strip dirty, and `FastLED.show()` is called once per main-loop iteration if anything changed.
 
 ### Serial command protocol
 
@@ -104,6 +104,6 @@ All commands reply `OK` or `ERR BAD_ID` / `ERR BAD_CMD` etc.
 ### Adding gauges
 
 1. Increment `GAUGE_COUNT`.
-2. Add a `constexpr GaugePins` entry to `gaugePins[]` (including `ledCount`).
+2. Add a `constexpr GaugePins` entry to `gaugePins[]` (including the `ledOrder` string — one char per LED, `'G'` for GRB or `'R'` for RGB).
 3. Tune `maxPos` and `homingBackoffSteps` in the corresponding `Gauge` default or at runtime.
-4. `TOTAL_LEDS` and `gaugeLedOffset[]` update automatically — no manual changes needed.
+4. `TOTAL_LEDS`, `gaugeLedOffset[]`, and `gaugeLedCount[]` update automatically — no manual changes needed.

Gaugecontroller/Gaugecontroller.ino

@@ -226,19 +226,23 @@ struct GaugePins {
   bool dirInverted;
   bool stepActiveHigh;
   bool enableActiveLow;
-  uint8_t ledCount;          // LEDs assigned to this gauge
+  const char* ledOrder;      // one char per LED: 'G' = GRB, 'R' = RGB; length defines ledCount
 };
 
 constexpr GaugePins gaugePins[GAUGE_COUNT] = {
-  // dir, step, en, dirInv, stepHigh, enActiveLow, leds
+  // dir, step, en, dirInv, stepHigh, enActiveLow, ledOrder
-  {50, 51, -1, false, true, true, 7},   // Gauge 0
+  {50, 51, -1, false, true, true, "RRRGGRR"},   // Gauge 0
-  {8,  9,  -1, true,  true, true, 7},   // Gauge 1
+  {8,  9,  -1, true,  true, true, "GGGRRRR"},   // Gauge 1
-  {52, 53, -1, false, true, true, 7},   // Gauge 2
+  {52, 53, -1, false, true, true, "GGGRRRR"},   // Gauge 2
-  {48, 49, -1, false, true, true, 7},   // Gauge 3
+  {48, 49, -1, false, true, true, "GGGRRRR"},   // Gauge 3
 };
 
+constexpr uint8_t cstrLen(const char* s) {
+  return *s ? uint8_t(1 + cstrLen(s + 1)) : uint8_t(0);
+}
+
 constexpr uint8_t sumLedCounts(uint8_t i = 0) {
-  return i >= GAUGE_COUNT ? 0 : gaugePins[i].ledCount + sumLedCounts(i + 1);
+  return i >= GAUGE_COUNT ? 0 : cstrLen(gaugePins[i].ledOrder) + sumLedCounts(i + 1);
 }
 static const uint8_t TOTAL_LEDS = sumLedCounts();
 
@@ -298,9 +302,40 @@ String rxLine;
 
 CRGB leds[TOTAL_LEDS];
 uint8_t gaugeLedOffset[GAUGE_COUNT];
+uint8_t gaugeLedCount[GAUGE_COUNT];
 BlinkState blinkState[TOTAL_LEDS];
 bool ledsDirty = false;
 
+// FastLED drives the shared strip as RGB. Each gauge's ledOrder string marks per-LED
+// type ('R' = RGB, 'G' = GRB); writes to GRB-ordered LEDs pre-swap R and G to compensate.
+inline bool ledNeedsRgSwap(uint8_t globalIdx) {
+  for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
+    uint8_t off = gaugeLedOffset[i];
+    if (globalIdx >= off && globalIdx < off + gaugeLedCount[i]) {
+      char c = gaugePins[i].ledOrder[globalIdx - off];
+      return c == 'G' || c == 'g';
+    }
+  }
+  return false;
+}
+
+inline CRGB encodeForStrip(uint8_t globalIdx, CRGB color) {
+  if (ledNeedsRgSwap(globalIdx)) {
+    uint8_t tmp = color.r;
+    color.r = color.g;
+    color.g = tmp;
+  }
+  return color;
+}
+
+inline void writeLed(uint8_t globalIdx, CRGB color) {
+  leds[globalIdx] = encodeForStrip(globalIdx, color);
+}
+
+inline CRGB readLed(uint8_t globalIdx) {
+  return encodeForStrip(globalIdx, leds[globalIdx]);
+}
+
 // Sends one-line command replies back over the control port.
 //
 // Serial protocol summary.
@@ -854,8 +889,8 @@ bool parseVfd(const String& line) {
 bool parseLedQuery(const String& line) {
   if (line == "LED?") {
     for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
-      for (uint8_t j = 0; j < gaugePins[i].ledCount; j++) {
+      for (uint8_t j = 0; j < gaugeLedCount[i]; j++) {
-        const CRGB& c = leds[gaugeLedOffset[i] + j];
+        CRGB c = readLed(gaugeLedOffset[i] + j);
         CMD_PORT.print("LED ");
         CMD_PORT.print(i);
         CMD_PORT.print(' ');
@@ -884,13 +919,13 @@ bool parseLed(const String& line) {
     char* dash = strchr(idxToken, '-');
     int idxFirst = atoi(idxToken);
     int idxLast  = dash ? atoi(dash + 1) : idxFirst;
-    if (idxFirst < 0 || idxLast >= gaugePins[id].ledCount || idxFirst > idxLast) {
+    if (idxFirst < 0 || idxLast >= gaugeLedCount[id] || idxFirst > idxLast) {
       sendReply("ERR BAD_IDX"); return true;
     }
     CRGB color(constrain(r, 0, 255), constrain(g, 0, 255), constrain(b, 0, 255));
     for (int i = idxFirst; i <= idxLast; i++) {
       blinkState[gaugeLedOffset[id] + i].active = false;
-      leds[gaugeLedOffset[id] + i] = color;
+      writeLed(gaugeLedOffset[id] + i, color);
     }
     ledsDirty = true;
     sendReply("OK");
@@ -913,7 +948,7 @@ bool parseBlink(const String& line) {
   char* dash = strchr(idxToken, '-');
   int idxFirst = atoi(idxToken);
   int idxLast  = dash ? atoi(dash + 1) : idxFirst;
-  if (idxFirst < 0 || idxLast >= gaugePins[id].ledCount || idxFirst > idxLast) {
+  if (idxFirst < 0 || idxLast >= gaugeLedCount[id] || idxFirst > idxLast) {
     sendReply("ERR BAD_IDX"); return true;
   }
 
@@ -934,13 +969,13 @@ bool parseBlink(const String& line) {
     uint8_t globalIdx = gaugeLedOffset[id] + i;
     BlinkState& bs = blinkState[globalIdx];
     bs.fx       = FX_BLINK;
-    bs.onColor  = (count == 7) ? color : leds[globalIdx];
+    bs.onColor  = (count == 7) ? color : readLed(globalIdx);
     bs.onMs     = (uint16_t)onMs;
     bs.offMs    = (uint16_t)offMs;
     bs.currentlyOn = true;
     bs.lastMs   = nowMs;
     bs.active   = true;
-    leds[globalIdx] = bs.onColor;
+    writeLed(globalIdx, bs.onColor);
   }
   ledsDirty = true;
   sendReply("OK");
@@ -958,7 +993,7 @@ bool parseBreathe(const String& line) {
   char* dash = strchr(idxToken, '-');
   int idxFirst = atoi(idxToken);
   int idxLast  = dash ? atoi(dash + 1) : idxFirst;
-  if (idxFirst < 0 || idxLast >= gaugePins[id].ledCount || idxFirst > idxLast) {
+  if (idxFirst < 0 || idxLast >= gaugeLedCount[id] || idxFirst > idxLast) {
     sendReply("ERR BAD_IDX"); return true;
   }
   if (periodMs <= 0) { sendReply("ERR BAD_TIME"); return true; }
@@ -973,7 +1008,7 @@ bool parseBreathe(const String& line) {
     bs.cyclePos = 0;
     bs.lastMs   = nowMs;
     bs.active   = true;
-    leds[gi]    = CRGB::Black;
+    writeLed(gi, CRGB::Black);
   }
   ledsDirty = true;
   sendReply("OK");
@@ -991,7 +1026,7 @@ bool parseDflash(const String& line) {
   char* dash = strchr(idxToken, '-');
   int idxFirst = atoi(idxToken);
   int idxLast  = dash ? atoi(dash + 1) : idxFirst;
-  if (idxFirst < 0 || idxLast >= gaugePins[id].ledCount || idxFirst > idxLast) {
+  if (idxFirst < 0 || idxLast >= gaugeLedCount[id] || idxFirst > idxLast) {
     sendReply("ERR BAD_IDX"); return true;
   }
   CRGB color(constrain(r, 0, 255), constrain(g, 0, 255), constrain(b, 0, 255));
@@ -1004,7 +1039,7 @@ bool parseDflash(const String& line) {
     bs.dphase  = 0;
     bs.lastMs  = nowMs;
     bs.active  = true;
-    leds[gi]   = color;  // phase 0 = on
+    writeLed(gi, color);  // phase 0 = on
   }
   ledsDirty = true;
   sendReply("OK");
@@ -1017,7 +1052,7 @@ void updateBlink() {
   bool changed = false;
 
   for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
-    for (uint8_t j = 0; j < gaugePins[i].ledCount; j++) {
+    for (uint8_t j = 0; j < gaugeLedCount[i]; j++) {
       uint8_t gi = gaugeLedOffset[i] + j;
       BlinkState& bs = blinkState[gi];
       if (!bs.active) continue;
@@ -1028,7 +1063,7 @@ void updateBlink() {
           if ((nowMs - bs.lastMs) >= period) {
             bs.currentlyOn = !bs.currentlyOn;
             bs.lastMs = nowMs;
-            leds[gi] = bs.currentlyOn ? bs.onColor : CRGB::Black;
+            writeLed(gi, bs.currentlyOn ? bs.onColor : CRGB::Black);
             changed = true;
           }
           break;
@@ -1044,8 +1079,9 @@ void updateBlink() {
           uint8_t bri = (bs.cyclePos < half)
               ? (uint8_t)((uint32_t)bs.cyclePos * 255 / half)
               : (uint8_t)((uint32_t)(bs.periodMs - bs.cyclePos) * 255 / half);
-          leds[gi] = bs.onColor;
+          CRGB scaled = bs.onColor;
-          leds[gi].nscale8(bri ? bri : 1);
+          scaled.nscale8(bri ? bri : 1);
+          writeLed(gi, scaled);
           changed = true;
           break;
         }
@@ -1054,7 +1090,7 @@ void updateBlink() {
           if ((nowMs - bs.lastMs) >= dur[bs.dphase]) {
             bs.lastMs = nowMs;
             bs.dphase = (bs.dphase + 1) & 3;
-            leds[gi] = (bs.dphase == 0 || bs.dphase == 2) ? bs.onColor : CRGB::Black;
+            writeLed(gi, (bs.dphase == 0 || bs.dphase == 2) ? bs.onColor : CRGB::Black);
             changed = true;
           }
           break;
@@ -1135,10 +1171,11 @@ void setup() {
   // Flatten the per-gauge LED counts into offsets on the shared strip.
   uint8_t ledOff = 0;
   for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
+    gaugeLedCount[i] = cstrLen(gaugePins[i].ledOrder);
     gaugeLedOffset[i] = ledOff;
-    ledOff += gaugePins[i].ledCount;
+    ledOff += gaugeLedCount[i];
   }
-  FastLED.addLeds<WS2812B, LED_DATA_PIN, GRB>(leds, TOTAL_LEDS);
+  FastLED.addLeds<WS2812B, LED_DATA_PIN, RGB>(leds, TOTAL_LEDS);
   FastLED.setBrightness(255);
   FastLED.show();