powermate

powermate.py

"""
Griffin PowerMate Python 3 library for Windows
Ported from crash7/griffin-powermate (Python 2)
Requires: pip install pywinusb
"""

from pywinusb.hid import HidDevice, HidDeviceFilter

def find_griffin_powermate():
    return GriffinPowermate.find_all()

class GriffinPowermate():
    VENDOR = 0x077d
    PRODUCT = 0x0410
    MOVE_LEFT = -1
    MOVE_RIGHT = 1

    def __init__(self, raw_device):
        self.__device = raw_device
        self.__device.set_raw_data_handler(lambda raw_data: self.__internal_listener(raw_data))
        self.__events = {}

    @classmethod
    def find_all(cls):
        return [cls(device) for device in HidDeviceFilter(vendor_id=cls.VENDOR, product_id=cls.PRODUCT).get_devices()]

    def __internal_listener(self, raw_data):
        """
        [0, button_status, move, 0, bright, pulse_status, pulse_value]
        move byte: 1-127 = clockwise (higher = faster), 129-255 = counter-clockwise (lower = faster)
        """
        raw_move = raw_data[2]
        if raw_move == 0:
            delta = 0
        elif raw_move < 128:
            delta = raw_move       # positive = clockwise
        else:
            delta = raw_move - 256 # negative = counter-clockwise

        if 'move' in self.__events:
            self.__events['move'](delta, raw_data[1])
        if 'raw' in self.__events:
            self.__events['raw'](raw_data)

    def is_plugged(self):
        return self.__device.is_plugged()

    def open(self):
        if not self.__device.is_opened():
            self.__device.open()

    def close(self):
        if self.__device.is_opened():
            self.__device.close()

    def on_event(self, event, callback):
        self.__events[event] = callback

    def set_brightness(self, bright):
        self.__device.send_feature_report([0, 0x41, 0x01, 0x01, 0x00, bright % 255, 0x00, 0x00, 0x00])

    def set_led_pulsing_status(self, on=True):
        self.__device.send_feature_report([0, 0x41, 0x01, 0x03, 0x00, 0x01 if on else 0x00, 0x00, 0x00, 0x00])

    def set_led_pulsing_default(self):
        self.__device.send_feature_report([0, 0x41, 0x01, 0x04, 0x00, 0x01, 0x00, 0x00, 0x00])


if __name__ == '__main__':
    from time import sleep
    from msvcrt import kbhit

    position = 0

    def move_listener(delta, button):
        global position
        position += delta

        # LED on while button held
        if button:
            powermate.set_brightness(254)
        else:
            powermate.set_brightness(0)

        direction = 'CW' if delta > 0 else 'CCW' if delta < 0 else '--'
        print("Pos: {:<6d}  Delta: {:<+4d}  Speed: {:<3d}  Dir: {}  Button: {}".format(
            position, delta, abs(delta), direction, button))

    def raw_listener(data):
        # handle button press/release even without rotation
        if data[2] == 0:
            if data[1]:
                powermate.set_brightness(254)
            else:
                powermate.set_brightness(0)

    devices = GriffinPowermate.find_all()
    if len(devices) > 0:
        print("Found Powermates")
        powermate = devices[0]

        try:
            powermate.open()
            powermate.set_led_pulsing_status(False)
            powermate.set_brightness(0)
            powermate.on_event('move', move_listener)
            powermate.on_event('raw', raw_listener)

            print("\nPos       Delta  Speed  Dir  Button")
            print("-----  ------  -----  ---  ------")
            print("Waiting for data... Press any keyboard key to stop.\n")
            while not kbhit() and powermate.is_plugged():
                sleep(0.5)
        finally:
            powermate.set_brightness(0)
            powermate.close()
    else:
        print("No PowerMate found. Is it plugged in?")