initial version with serial link

analog_system_monitor_arduino/Command_Summary.txt

@@ -0,0 +1,54 @@
+COMMAND BEHAVIOR SUMMARY
+========================
+
+PING
+----
+Format:
+    PING
+
+Response:
+    Analog_System_Monitor_<version>
+
+Purpose:
+    - Confirms the device is alive
+    - Allows PC-side auto-discovery
+    - Returns firmware version
+
+
+SETALL
+------
+Format:
+    SETALL: v0,v1,v2,v3,v4,v5,v6,v7
+
+Rules:
+    - Exactly 8 comma-separated values
+    - Each value must be numeric
+    - Each value must be between 0 and 100
+    - No extra values allowed
+    - No missing values allowed
+    - No trailing commas or extra characters
+
+Success Response:
+    OK
+
+Error Response:
+    ERROR
+
+Purpose:
+    - Updates all 8 channels in one atomic operation
+    - Applies calibration to each channel
+    - Resets watchdog timer
+
+
+UNKNOWN / MALFORMED COMMANDS
+----------------------------
+Format:
+    Anything not matching PING or a valid SETALL command
+
+Response:
+    ERROR
+
+Purpose:
+    - Keeps protocol strict and predictable
+    - Prevents accidental meter movement
+    - Simplifies debugging

analog_system_monitor_arduino/analog_system_monitor_arduino.ino

@@ -103,19 +103,68 @@ void loop() {
       continue;
     }
 
-    int eq = s.indexOf('=');
-    if (eq > 0) {
-      int ch = s.substring(0, eq).toInt();
-      float val = s.substring(eq + 1).toFloat();
-      if (ch >= 0 && ch < NUM_CHANNELS && val >= 0.0f && val <= 100.0f) {
+    // --- Batch update command ---
+    if (s.startsWith("SETALL:")) {
+      String payload = s.substring(7);
+      payload.trim();
 
-        currentDuty[ch] = val;
+      float newValues[NUM_CHANNELS];
+      int count = 0;
+      bool error = false;
 
+      // Parse up to NUM_CHANNELS values
+      while (payload.length() > 0 && count < NUM_CHANNELS) {
+        int comma = payload.indexOf(',');
+        String part;
+
+        if (comma >= 0) {
+          part = payload.substring(0, comma);
+          payload = payload.substring(comma + 1);
+        } else {
+          part = payload;
+          payload = "";
+        }
+
+        part.trim();
+        if (part.length() == 0) {
+          error = true;
+          break;
+        }
+
+        float val = part.toFloat();
+
+        if (val < 0.0f || val > 100.0f) {
+          error = true;
+          break;
+        }
+
+        newValues[count++] = val;
+      }
+
+      // Conditions for a valid SETALL:
+      // - exactly NUM_CHANNELS values parsed
+      // - no leftover payload
+      // - no parse/range errors
+      if (error || count != NUM_CHANNELS || payload.length() > 0) {
+        Serial.println("ERROR");
+        continue;
+      }
+
+      // All good → apply values
+      for (int ch = 0; ch < NUM_CHANNELS; ch++) {
+        currentDuty[ch] = newValues[ch];
         float calibratedDuty = applyCalibration(ch, currentDuty[ch]);
         pwm[ch]->setPWM(pwmPins[ch], pwmFrequency, calibratedDuty);
-
-        lastSerialTime = millis();  // reset watchdog
       }
+
+      Serial.println("OK");
+      lastSerialTime = millis();
+      continue;
+    }
+
+    // --- Unknown command ---
+    if (s.length() > 0) {
+      Serial.println("ERROR");
     }
   }