From 4a7551e358e997dfde01b11ea2e9fbf9c5eb3740 Mon Sep 17 00:00:00 2001
From: "Adrian A. Baumann" <ade@adebaumann.com>
Date: Wed, 15 Apr 2026 21:53:01 +0200
Subject: [PATCH] Blinking added to Arduino

---
 CLAUDE.md                           |  3 +-
 Gaugecontroller/Gaugecontroller.ino | 79 ++++++++++++++++++++++++++++-
 2 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/CLAUDE.md b/CLAUDE.md
index e2c5422..b3e24f8 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -90,8 +90,9 @@ Commands arrive as newline-terminated ASCII lines. Each `parse*` function in `pr
 | `HOME` | `HOME <id>` / `HOMEALL` | Run homing sequence |
 | `SWEEP` | `SWEEP <id> <accel> <speed>` | Start sweep (0/0 stops) |
 | `POS?` | `POS?` | Query all gauges: `POS <id> <cur> <tgt> <homed> <homingState> <sweep>` |
-| `LED` | `LED <id> <idx> <r> <g> <b>` | Set one LED (0-based index within gauge segment) to RGB colour (0–255 each); `<idx>` may be a range `N-M` to set LEDs N through M in one command |
+| `LED` | `LED <id> <idx> <r> <g> <b>` | Set one LED (0-based index within gauge segment) to RGB colour (0–255 each); `<idx>` may be a range `N-M` to set LEDs N through M in one command; also stops any active blink on those LEDs |
 | `LED?` | `LED?` | Query all LEDs: one `LED <id> <idx> <r> <g> <b>` line per LED, then `OK` |
+| `BLINK` | `BLINK <id> <idx> <on_ms> <off_ms>` | Blink LED(s) using their current colour as the on-colour; `<idx>` may be a range `N-M`; `on_ms`/`off_ms` must both be > 0, or both 0 to stop blinking |
 | `PING` | `PING` | Responds `PONG` |
 
 All commands reply `OK` or `ERR BAD_ID` / `ERR BAD_CMD` etc.
diff --git a/Gaugecontroller/Gaugecontroller.ino b/Gaugecontroller/Gaugecontroller.ino
index bc21c94..ec41ad9 100644
--- a/Gaugecontroller/Gaugecontroller.ino
+++ b/Gaugecontroller/Gaugecontroller.ino
@@ -70,11 +70,21 @@ struct Gauge {
   bool sweepTowardMax = true;
 };
 
+struct BlinkState {
+  bool active = false;
+  uint32_t onMs = 500;
+  uint32_t offMs = 500;
+  CRGB onColor;
+  bool currentlyOn = false;
+  unsigned long lastToggleMs = 0;
+};
+
 Gauge gauges[GAUGE_COUNT];
 String rxLine;
 
 CRGB leds[TOTAL_LEDS];
 uint8_t gaugeLedOffset[GAUGE_COUNT];
+BlinkState blinkState[TOTAL_LEDS];
 
 void sendReply(const String& s) {
   CMD_PORT.println(s);
@@ -531,8 +541,10 @@ bool parseLed(const String& line) {
       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++)
+    for (int i = idxFirst; i <= idxLast; i++) {
+      blinkState[gaugeLedOffset[id] + i].active = false;
       leds[gaugeLedOffset[id] + i] = color;
+    }
     FastLED.show();
     sendReply("OK");
     return true;
@@ -540,6 +552,69 @@ bool parseLed(const String& line) {
   return false;
 }
 
+bool parseBlink(const String& line) {
+  int id;
+  char idxToken[16];
+  long onMs, offMs;
+  if (sscanf(line.c_str(), "BLINK %d %15s %ld %ld", &id, idxToken, &onMs, &offMs) == 4) {
+    if (id < 0 || id >= GAUGE_COUNT) { sendReply("ERR BAD_ID"); return true; }
+    char* dash = strchr(idxToken, '-');
+    int idxFirst = atoi(idxToken);
+    int idxLast  = dash ? atoi(dash + 1) : idxFirst;
+    if (idxFirst < 0 || idxLast >= gaugePins[id].ledCount || idxFirst > idxLast) {
+      sendReply("ERR BAD_IDX"); return true;
+    }
+
+    if (onMs == 0 && offMs == 0) {
+      for (int i = idxFirst; i <= idxLast; i++)
+        blinkState[gaugeLedOffset[id] + i].active = false;
+      sendReply("OK");
+      return true;
+    }
+    if (onMs <= 0 || offMs <= 0) { sendReply("ERR BAD_TIME"); return true; }
+
+    unsigned long nowMs = millis();
+    for (int i = idxFirst; i <= idxLast; i++) {
+      uint8_t globalIdx = gaugeLedOffset[id] + i;
+      BlinkState& bs = blinkState[globalIdx];
+      bs.onColor = leds[globalIdx];
+      bs.onMs = (uint32_t)onMs;
+      bs.offMs = (uint32_t)offMs;
+      bs.currentlyOn = true;
+      bs.lastToggleMs = nowMs;
+      bs.active = true;
+      leds[globalIdx] = bs.onColor;
+    }
+    FastLED.show();
+    sendReply("OK");
+    return true;
+  }
+  return false;
+}
+
+void updateBlink() {
+  unsigned long nowMs = millis();
+  bool changed = false;
+
+  for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
+    for (uint8_t j = 0; j < gaugePins[i].ledCount; j++) {
+      uint8_t globalIdx = gaugeLedOffset[i] + j;
+      BlinkState& bs = blinkState[globalIdx];
+      if (!bs.active) continue;
+
+      uint32_t period = bs.currentlyOn ? bs.onMs : bs.offMs;
+      if ((nowMs - bs.lastToggleMs) >= period) {
+        bs.currentlyOn = !bs.currentlyOn;
+        bs.lastToggleMs = nowMs;
+        leds[globalIdx] = bs.currentlyOn ? bs.onColor : CRGB::Black;
+        changed = true;
+      }
+    }
+  }
+
+  if (changed) FastLED.show();
+}
+
 void processLine(const String& line) {
   if (parseSet(line)) return;
   if (parseSpeed(line)) return;
@@ -551,6 +626,7 @@ void processLine(const String& line) {
   if (parsePosQuery(line)) return;
   if (parseLedQuery(line)) return;
   if (parseLed(line)) return;
+  if (parseBlink(line)) return;
   if (parsePing(line)) return;
 
   sendReply("ERR BAD_CMD");
@@ -613,6 +689,7 @@ void setup() {
 
 void loop() {
   readCommands();
+  updateBlink();
 
   for (uint8_t i = 0; i < GAUGE_COUNT; i++) {
     updateGauge(i);