GreatFET-based push to talk button

push_to_talk.py

#
# This file is part of LUNA.
#

import asyncio
import logging

from greatfet   import GreatFET

from facedancer import main
from facedancer.devices.keyboard     import USBKeyboardDevice
from facedancer.classes.hid.keyboard import KeyboardModifiers, KeyboardKeys

device = USBKeyboardDevice()

BUTTON  = 'J1_P3'
KEYCODE = KeyboardKeys.PAUSE

async def handle_button_presses():

    # Steal the GreatFET from our device.
    # (This is lazy; we probably should have created it ourself and passed it to the Device initializer.)
    gf = device.backend.device

    # Grab our button, and set it to be an input.
    button = gf.gpio.get_pin(BUTTON)
    button.set_direction(button.DIRECTION_IN)

    while True:

        # Sleep for a little bit to let the USB processing happen.
        # This is the USB interrupt interval; so sleeping for any less than
        # this isn't really useful anyways.
        await asyncio.sleep(0.1)

        # ... and then process our button state.
        if button.read():
            device.all_keys_up()
        else:
            device.key_down(KEYCODE)


main(device, handle_button_presses())