Breathing acceleration: configurable threshold

The LED breathing effect will double its
speed, if a specific CO2 concentration is
exceeded.

ampel-firmware/config.public.h

@@ -66,6 +66,9 @@
 
 // Should the LED display show a breathing effect during measurement?
 #  define LED_BREATHING true // [true / false]
+// Accelerate breathing above this CO2 concentration.
+#  define LED_BREATHING_ACCEL_THRESHOLD 1600 // [ppm]
+
 
 /**
  * WEB SERVER

ampel-firmware/led_effects.cpp

@@ -5,6 +5,7 @@
 namespace config {
   const uint8_t max_brightness = MAX_BRIGHTNESS;
   const uint8_t min_brightness = MIN_BRIGHTNESS;
+  const uint16_t led_breathing_accel_threshold = LED_BREATHING_ACCEL_THRESHOLD;
   const int kitt_tail = 3; // How many dimmer LEDs follow in K.I.T.T. wheel
 }
 
@@ -189,7 +190,7 @@ namespace led_effects {
     pixels.setBrightness(brightness);
     pixels.show();
     breathing_offset += 3; // breathing speed. +3 looks like slow human breathing.
-    delay(co2 > 1600 ? 50 : 100); // faster breathing for higher CO2 values
+    delay(co2 > config::led_breathing_accel_threshold ? 50 : 100); // faster breathing for higher CO2 values
   }
 
   /**