Implement common add-on boards, re: #17

gpiozero/boards.py

@@ -0,0 +1,61 @@
+from .input_devices import Button
+from .output_devices import LED
+from .devices import GPIODeviceError
+
+
+class TrafficLights(object):
+    def __init__(self, red=None, amber=None, green=None):
+        if not all([red, amber, green]):
+            raise GPIODeviceError('Red, Amber and Green pins must be provided')
+
+        self.red = LED(red)
+        self.amber = LED(amber)
+        self.green = LED(green)
+        self.lights = [self.red, self.amber, self.green]
+
+    def lights_on(self):
+        for led in self.lights:
+            led.on()
+
+    def lights_off(self):
+        for led in self.lights:
+            led.off()
+
+
+class PiTraffic(TrafficLights):
+    def __init__(self):
+        self.red = LED(9)
+        self.amber = LED(10)
+        self.green = LED(11)
+        self.lights = [self.red, self.amber, self.green]
+
+
+class FishDish(TrafficLights):
+    def __init__(self):
+        red, amber, green = (9, 22, 4)
+        super(FishDish, self).__init__(red, amber, green)
+        self.buzzer = Buzzer(8)
+        self.button = Button(7)
+        self.all = self.lights + [self.buzzer]
+
+    def on(self):
+        for led in self.all:
+            led.on()
+
+    def off(self):
+        for led in self.all:
+            led.off()
+
+
+class PiLiter(object):
+    def __init__(self):
+        leds = [4, 17, 27, 18, 22, 23, 24, 25]
+        self.leds = [LED(led) for led in leds]
+
+    def on(self):
+        for led in self.leds:
+            led.on()
+
+    def off(self):
+        for led in self.leds:
+            led.off()