3x1-keyboard.py

import time
import board
import digitalio
import usb_hid
from adafruit_hid.consumer_control import ConsumerControl
from adafruit_hid.consumer_control_code import ConsumerControlCode


def init_pin(pin_id):
    pin = digitalio.DigitalInOut(pin_id)
    pin.direction = digitalio.Direction.INPUT
    pin.pull = digitalio.Pull.UP
    return pin


def key_pressed(pin):
    return not pin.value


def handle_volume(playpause_pin):
    global pins, key_codes, cc

    volume_changed = False

    while key_pressed(playpause_pin):
        for pin_id, pin in pins.items():
            if pin == playpause_pin:
                continue

            if not key_pressed(pin):
                continue

            inner_key_code = key_codes[pin_id]
            volume_changed = True

            if inner_key_code == ConsumerControlCode.SCAN_PREVIOUS_TRACK:
                cc.send(ConsumerControlCode.VOLUME_DECREMENT)
            elif inner_key_code == ConsumerControlCode.SCAN_NEXT_TRACK:
                cc.send(ConsumerControlCode.VOLUME_INCREMENT)

            cc.release()
            time.sleep(0.05)
    
    return volume_changed


key_codes = {
    board.D6: ConsumerControlCode.SCAN_PREVIOUS_TRACK,
    board.D7: ConsumerControlCode.PLAY_PAUSE,
    board.D5: ConsumerControlCode.SCAN_NEXT_TRACK,
}

pins = {
    pin_id: init_pin(pin_id)
    for pin_id in key_codes.keys()
}

cc = ConsumerControl(usb_hid.devices)

while True:
    for pin_id, pin in pins.items():
        if not key_pressed(pin):
            continue

        key_code = key_codes[pin_id]

        if key_code == ConsumerControlCode.PLAY_PAUSE:
            volume_changed = handle_volume(pin)
            if not volume_changed:
                cc.send(key_code)
                cc.release()
                time.sleep(0.01)
        else:
            # Handle next/previous track
            cc.send(key_code)

            while key_pressed(pin):
                # wait for button release
                pass

            cc.release()
            time.sleep(0.01)