add rainbow idle animation

dmx_queue.py

@@ -1,4 +1,5 @@
 import logging
+from colorsys import hsv_to_rgb
 from queue import Empty
 from threading import Thread
 from time import sleep
@@ -58,6 +59,7 @@ class DMXQueue:
 
     def _worker(self):
         LOG.info('Worker startup')
+        rotation = 0
         while self.worker_should_be_running:
             try:
                 level, component, text = self.queue.get_nowait()
@@ -99,5 +101,25 @@ class DMXQueue:
                             sleep(0.03)
                 self.queue.task_done()
             except Empty:
-                sleep(0.1)
+                degrees_per_step = 360 / len(self.lights)
+
+                for idx, light in enumerate(self.lights):
+                    light_degrees_dec = (
+                        (rotation + (idx * degrees_per_step)) % 360 / 360
+                    )
+                    r, g, b = hsv_to_rgb(
+                        light_degrees_dec, 1, self.args.rainbow_intensity / 100
+                    )
+
+                    light.red = int(r * 255)
+                    light.green = int(g * 255)
+                    light.blue = int(b * 200)
+                    light.intensity = self.args.rainbow_brightness
+                    self._bulk(*light.dump())
+
+                rotation = rotation + 1
+                if rotation >= 360:
+                    rotation = 0
+
+                sleep(self.args.rainbow_speed / 1000)
         LOG.info('Worker shutdown')

main.py

@@ -24,6 +24,26 @@ def main():
 
     parser = ArgumentParser()
 
+    # rainbow is output if we have no effects
+    parser.add_argument(
+        '--rainbow-intensity',
+        type=int,
+        default=50,
+        help='intensity of the rainbow colours in percent ("value" in HSV)',
+    )
+    parser.add_argument(
+        '--rainbow-brightness',
+        type=int,
+        default=150,
+        help='brightness of the rainbow colour (dmx value of dimmer)',
+    )
+    parser.add_argument(
+        '--rainbow-speed',
+        type=int,
+        default=10,
+        help='speed of rainbow colour change (ms per degree hue)',
+    )
+
     # MQTT
     parser.add_argument('--mqtt-host', required=True)
     parser.add_argument('--mqtt-port', type=int, default=1883)