CircuitPython Trellis M4 Keyboard Demo

trellis-keyboard.py

# CircuitPython + Trellis M4 Keyboard emulator. Fits in your pocket!
# using https://www.adafruit.com/product/4020
#
# Should work on any PC

import time
import board
import digitalio
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS
from adafruit_hid.keycode import Keycode

# CircuitPython demo - Keypad
from digitalio import DigitalInOut
import board
import adafruit_matrixkeypad

# lights

cols = []
for x in range(8):
    cols.append(DigitalInOut(getattr(board, "COL{}".format(x))))

rows = []
for y in range(4):
    rows.append(DigitalInOut(getattr(board, "ROW{}".format(y))))

key_names = []
for y in range(8):
    row = []
    for x in range(4):
        coord = (x, y)
        row.append(coord)
    key_names.append(row)

keypad = adafruit_matrixkeypad.Matrix_Keypad(cols, rows, key_names)

key_names = {
    (0, 0): 'a',
    (0, 1): 'b',
    (0, 2): 'c',
    (0, 3): 'd',
    (0, 4): 'e',
    (0, 5): 'f',
    (0, 6): 'g',
    (0, 7): 'h',

    (1, 0): 'i',
    (1, 1): 'j',
    (1, 2): 'k',
    (1, 3): 'l',
    (1, 4): 'm',
    (1, 5): 'n',
    (1, 6): 'o',
    (1, 7): 'p',

    (2, 0): 'q',
    (2, 1): 'r',
    (2, 2): 's',
    (2, 3): 't',
    (2, 4): 'u',
    (2, 5): 'v',
    (2, 6): 'w',
    (2, 7): 'x',

    (3, 0): 'y',
    (3, 1): 'z',
    (3, 2): '.',
    (3, 3): '!',
    (3, 4): '?',
    (3, 5): ' ',
    (3, 6): ' ',
    (3, 7): Keycode.BACKSPACE,
}

import neopixel
pixels = neopixel.NeoPixel(board.NEOPIXEL, 32, brightness=0.3, auto_write=False)
pixels.fill(0)
pixels.show()

# The keyboard object!
time.sleep(1)  # Sleep for a bit to avoid a race condition on some systems
keyboard = Keyboard()
keyboard_layout = KeyboardLayoutUS(keyboard)  # We're in the US :)

pressed = {}

while True:
    keys = keypad.pressed_keys
    if keys:
        print("Pressed: ", keys)
        for k in keys:
            is_pressed = pressed.get(k, False)
            if not is_pressed:
                key = key_names.get(k, None)
                if isinstance(key, str):  # If it's a string...
                    keyboard_layout.write(key)  # ...Print the string
                else:  # If it's not a string...
                    keyboard.press(key)  # "Press"...
                    keyboard.release_all()  # ..."Release"!
                pixels[k[0] * 8 + k[1]] = (0, 0, 100)
                pressed[k] = True

        # unpress keys that aren't currently being held
        for k, value in pressed.items():
            print("was pressed: ", k)
            if k in keys:
                print("  ", k, " is pressed")
            else:
                print("  k ", k, " was released")
                pixels[k[0] * 8 + k[1]] = (0, 0, 0)
                pressed[k] = False
    else:
        for k, value in pressed.items():
            pixels[k[0] * 8 + k[1]] = (0, 0, 0)
            pressed[k] = False
    pixels.show()
    time.sleep(0.01)