 void setup() {
   pinMode(LED_PIN_RED, OUTPUT);
   pinMode(LED_PIN_GREEN, OUTPUT);
-  pinMode(LED_PIN_YELLOW, OUTPUT);
+  pinMode(DEBUG_LED2, OUTPUT);
   pinMode(LED_PIN_INT, OUTPUT);
 
   pinMode(TOUCH_PIN_A, OUTPUT);

// for most LEDs.
#define LED_PIN_GREEN 16
#define LED_PIN_RED 17
#define LED_PIN_YELLOW 5  // or 21

// Pins for the relay based touch probes, collide with LEDs above
#define TOUCH_PIN_A 16

    } else if (cmd == CMD_SEND_LAST_LASER) {
      send_trigger(laser);
      laser.count = 0;
    } else if (cmd == CMD_BRIGHTNESS_CURVE) {
      send_ack(CMD_BRIGHTNESS_CURVE);
      // This blocks all other execution for about 1 second
      run_brightness_curve();
    } else {
      Serial.print("Unknown command:");
      Serial.println(cmd);
