Add a LED for chassis

mozc-nazoru/src/nazoru/led.py

@@ -29,13 +29,13 @@ class LEDBase():
 try:
   import RPi.GPIO as GPIO
   import threading
+  GPIO.setmode(GPIO.BOARD)
 
   class LED(LEDBase):
     ON = 'ON'
     OFF = 'OFF'
 
     def __init__(self, pin):
-      GPIO.setmode(GPIO.BOARD)
       self._pin = pin
       self._lock = threading.Lock()
       self._timer = None
@@ -72,6 +72,63 @@ try:
         self._timer.cancel()
         self._timer = None
 
+  import wiringpi
+  wiringpi.wiringPiSetupPhys()
+  class SlowLED(LEDBase):
+    DUTY_MAX = 1024
+    INTERVAL_MS = 10
+
+    def __init__(self, pin, delay_ms):
+      self._pin = pin
+      self._delay_ms = delay_ms
+      wiringpi.pinMode(pin, wiringpi.GPIO.PWM_OUTPUT)
+      self._target_duty = 0
+      self._current_duty = 0
+      self._remaining_cycles = 0
+      self._lock = threading.Lock()
+      self._timer = None
+      self.off()
+
+    # Called every 10ms
+    def _update(self):
+      with self._lock:
+        diff = (self._target_duty - self._current_duty) // \
+               self._remaining_cycles
+        self._current_duty += diff
+        self._remaining_cycles -= 1
+        self._set_duty_immediate(self._current_duty)
+        if self._remaining_cycles == 0:
+          self._timer.cancel()
+          self._timer = None
+          return
+        self._timer = threading.Timer(self.INTERVAL_MS * 0.001, self._update)
+        self._timer.daemon = True
+        self._timer.start()
+
+
+    # |duty|: 0 - 100
+    def _set_duty_immediate(self, duty):
+      wiringpi.pwmWrite(self._pin, int(self.DUTY_MAX * duty // 100))
+
+    def _set_duty_slow(self, duty, time_ms):
+      with self._lock:
+        self._target_duty = duty
+        self._remaining_cycles = time_ms // self.INTERVAL_MS
+        if self._timer is None:
+          self._timer = threading.Timer(self.INTERVAL_MS * 0.001, self._update)
+          self._timer.daemon = True
+          self._timer.start()
+
+    def on(self):
+      self._set_duty_slow(100, self._delay_ms)
+
+    def off(self):
+      self._set_duty_slow(0, self._delay_ms)
+
+    # |brightness|: 0 - 100
+    def set_brightness(self, brightness):
+      self._set_duty_slow(brightness, self._delay_ms)
+
 except ImportError as e:
   import sys
 
@@ -80,3 +137,4 @@ except ImportError as e:
 
 LED_BLUE = LED(38)
 LED_RED = LED(40)
+LED_CHASSIS = SlowLED(32, 500)