led_effects: rainbow wheel in both directions

ampel-firmware/led_effects.cpp

@@ -168,17 +168,18 @@ namespace led_effects {
     }
   }
 
-  void showRainbowWheel(uint16_t duration_ms, uint16_t hue_increment) {
+  void showRainbowWheel(uint16_t duration_ms) {
     if (config::night_mode) {
       return;
     }
     static uint16_t wheel_offset = 0;
+    static uint16_t sine_offset = 0;
     unsigned long t0 = millis();
     pixels.setBrightness(config::max_brightness);
     while (millis() - t0 < duration_ms) {
       for (int i = 0; i < NUMPIXELS; i++) {
         pixels.setPixelColor(i, pixels.ColorHSV(i * 65535 / NUMPIXELS + wheel_offset));
-        wheel_offset += hue_increment;
+        wheel_offset += (pixels.sine8(sine_offset++ / 50) - 127) / 2;
       }
       pixels.show();
       delay(10);

ampel-firmware/led_effects.h

@@ -29,7 +29,7 @@ namespace led_effects {
   int countdownToZero();
   void showWaitingLED(uint32_t color);
   void showKITTWheel(uint32_t color, uint16_t duration_s = 2);
-  void showRainbowWheel(uint16_t duration_ms = 1000, uint16_t hue_increment = 50);
+  void showRainbowWheel(uint16_t duration_ms = 1000);
   void displayCO2color(uint16_t co2);
 }
 #endif