wasp: Add a super-simple vibrator driver

wasp/boards/pinetime/manifest.py

@@ -5,6 +5,7 @@ freeze('../..',
         'drivers/battery.py',
         'drivers/signal.py',
         'drivers/st7789.py',
+        'drivers/vibrator.py',
         'logo.py',
     ),
     opt=3

wasp/boards/pinetime/watch.py

@@ -5,6 +5,7 @@ from machine import SPI
 from drivers.battery import Battery
 from drivers.signal import Signal
 from drivers.st7789 import ST7789_SPI
+from drivers.vibrator import Vibrator
 
 class Display(ST7789_SPI):
     def __init__(self):
@@ -51,3 +52,4 @@ battery = Battery(
         Pin('BATTERY', Pin.IN),
         Signal(Pin('CHARGING', Pin.IN), invert=True),
         Signal(Pin('USB_PWR', Pin.IN), invert=True))
+vibrator = Vibrator(Pin('MOTOR', Pin.OUT, value=0), active_low=True)

wasp/drivers/vibrator.py

@@ -0,0 +1,20 @@
+# Generic PWM capable vibrator
+
+import time
+from machine import PWM
+
+class Vibrator(object):
+    def __init__(self, pin, active_low=False):
+        pin.value(active_low)
+        self.pin = pin
+        self.freq = PWM.FREQ_16MHZ
+        self.period = 16000
+        self.active_low = active_low
+
+    def pulse(self, duty=50, ms=100):
+        pwm = PWM(0, self.pin, freq=self.freq, duty=duty, period=self.period)
+        pwm.init()
+        time.sleep_ms(ms)
+        pwm.deinit()
+        self.pin.value(self.active_low)
+