Add brightness control

src/aiy/_drivers/_led.py

@@ -17,6 +17,7 @@
 import itertools
 import threading
 import time
+import math
 import RPi.GPIO as GPIO
 
 
@@ -35,7 +36,7 @@ class LED:
     BLINK = 2
     BLINK_3 = 3
     BEACON = 4
-    BEACON_DARK = 5
+    BEACON_DARK = 0
     DECAY = 6
     PULSE_SLOW = 7
     PULSE_QUICK = 8
@@ -47,6 +48,7 @@ def __init__(self, channel):
         self.running = False
         self.state = None
         self.sleep = 0
+        self.brightness = 1
         GPIO.setmode(GPIO.BCM)
         GPIO.setup(channel, GPIO.OUT)
         self.pwm = GPIO.PWM(channel, 100)
@@ -78,6 +80,12 @@ def stop(self):
 
         self.pwm.stop()
 
+    def set_brightness(self, brightness):
+        try:
+            self.brightness = int(brightness)/100
+        except ValueError:
+            raise ValueError('unsupported brightness: %s' % brightness)
+
     def set_state(self, state):
         """Set the LED driver's new state.
 
@@ -118,35 +126,35 @@ def _parse_state(self, state):
             self.pwm.ChangeDutyCycle(100)
             handled = True
         elif state == self.BLINK:
-            self.iterator = itertools.cycle([0, 100])
+            self.iterator = itertools.cycle([0, int(100 * self.brightness)])
             self.sleep = 0.5
             handled = True
         elif state == self.BLINK_3:
-            self.iterator = itertools.cycle([0, 100] * 3 + [0, 0])
+            self.iterator = itertools.cycle([0, int(100 * self.brightness)] * 3 + [0, 0])
             self.sleep = 0.25
             handled = True
         elif state == self.BEACON:
             self.iterator = itertools.cycle(
-                itertools.chain([30] * 100, [100] * 8, range(100, 30, -5)))
+                itertools.chain([int(30 * self.brightness)] * 100, [int(100 * self.brightness)] * 8, range(int(100 * self.brightness), int(30 * self.brightness), 0 - math.ceil(4 * self.brightness))))
             self.sleep = 0.05
             handled = True
         elif state == self.BEACON_DARK:
             self.iterator = itertools.cycle(
-                itertools.chain([0] * 100, range(0, 30, 3), range(30, 0, -3)))
+                itertools.chain([0] * 100, range(0, int(30 * self.brightness), math.ceil(2 * self.brightness), range(int(30 * self.brightness), 0, 0 - math.ceil(2 * self.brightness)))))
             self.sleep = 0.05
             handled = True
         elif state == self.DECAY:
-            self.iterator = itertools.cycle(range(100, 0, -2))
+            self.iterator = self.iterator = itertools.cycle(range(int(100 * self.brightness), 0, int(math.ceil(-2 * self.brightness))))
             self.sleep = 0.05
             handled = True
         elif state == self.PULSE_SLOW:
             self.iterator = itertools.cycle(
-                itertools.chain(range(0, 100, 2), range(100, 0, -2)))
+                itertools.chain(range(0, int(100 * self.brightness), math.ceil(2 * self.brightness)), range(int(100 * self.brightness), 0, 0 - math.ceil(2 * self.brightness))))
             self.sleep = 0.1
             handled = True
         elif state == self.PULSE_QUICK:
             self.iterator = itertools.cycle(
-                itertools.chain(range(0, 100, 5), range(100, 0, -5)))
+                itertools.chain(range(0, int(100 * self.brightness), math.ceil(4 * self.brightness)), range(int(100 * self.brightness), 0, 0 - math.ceil(4 * self.brightness))))
             self.sleep = 0.05
             handled = True