hid-keypad-fifteen-layers.py

# SPDX-FileCopyrightText: 2021 Sandy Macdonald

# Modified by Frank Smith 2021 all the keys bar the modifier key
# can now be used as layer select and input keys
# prints debug messages via debug serial port (USB)
# sudo cat /dev/ttyACM0

# SPDX-License-Identifier: MIT

# An advanced example of how to set up a HID keyboard.

# There are four layers defined out of fifteen possible,
# selected by pressing and holding key 0 (bottom left), 
# then tapping one of the coloured layer selector keys to switch layer.

# The defined layer colours are as follows:

#  * layer 1: pink: numpad-style keys, 0-9, delete, and enter.
#  * layer 2: blue: sends strings on each key press
#  * layer 3: yellow: media controls, rev, play/pause, fwd on row one, vol. down, mute,
#             vol. up on row two
#  * layer 4: white: sends mixxx controls

import board
import time
from keybow2040 import Keybow2040

import usb_hid
from adafruit_hid.keyboard import Keyboard
from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS
from adafruit_hid.keycode import Keycode

from adafruit_hid.consumer_control import ConsumerControl
from adafruit_hid.consumer_control_code import ConsumerControlCode

# Set up Keybow
i2c = board.I2C()
keybow = Keybow2040(i2c)
keys = keybow.keys

# Set up the keyboard and layout
keyboard = Keyboard(usb_hid.devices)
layout = KeyboardLayoutUS(keyboard)

# Set up consumer control (used to send media key presses)
consumer_control = ConsumerControl(usb_hid.devices)

# Our layers. The key of item in the layer dictionary is the key number on
# Keybow to map to, and the value is the key press to send.

# Note that key 0 is reserved as the modifier

# purple - numeric keypad
layer_1 =     {4: Keycode.ZERO,
               5: Keycode.ONE,
               6: Keycode.FOUR,
               7: Keycode.SEVEN,
               8: Keycode.DELETE,
               9: Keycode.TWO,
               10: Keycode.FIVE,
               11: Keycode.EIGHT,
               12: Keycode.ENTER,
               13: Keycode.THREE,
               14: Keycode.SIX,
               15: Keycode.NINE}

# blue - words
layer_2 =     {7: "pack ",
               11: "my ",
               15: "box ",
               6: "with ",
               10: "five ",
               14: "dozen ",
               5: "liquor ",
               9: "jugs "}

# yellow - media controls
layer_3 =     {6: ConsumerControlCode.VOLUME_DECREMENT,
               7: ConsumerControlCode.SCAN_PREVIOUS_TRACK,
               10: ConsumerControlCode.MUTE,
               11: ConsumerControlCode.PLAY_PAUSE,
               14: ConsumerControlCode.VOLUME_INCREMENT,
               15: ConsumerControlCode.SCAN_NEXT_TRACK}

# white - mixxx
layer_4 =     {2: Keycode.X,
               5: Keycode.D,
               7: Keycode.T,
               8: Keycode.SPACE,
               13: Keycode.L,
               15: Keycode.Y}

layers =      {1: layer_1,
               2: layer_2,
               3: layer_3,
               4: layer_4}

selectors =   {1: keys[1],
               2: keys[2],
               3: keys[3],
               4: keys[4]}

# Define the modifier key and layer selector keys
modifier = keys[0]

# Start on layer 1
current_layer = 1

# The colours for each layer
colours = {1: (255, 0, 255),
           2: (0, 255, 255),
           3: (255, 255, 0),
           4: (128, 128, 128)}

layer_keys = range(0, 16)

# dictionary of sets (sets cannot be changed but can be replaced)
LEDs = {0: (64, 0, 0),
        1: (128, 0, 0),
        2: (196, 0, 0),
        3: (255, 0, 0),
        4: (0, 4, 0),
        5: (0, 128, 0),
        6: (0, 12, 0),
        7: (0, 196, 0),
        8: (0, 0, 64),
        9: (0, 0, 128),
        10: (0, 0, 196),
        11: (0, 0, 255),
        12: (64, 64, 0),
        13: (128, 128, 0),
        14: (196, 196, 0),
        15: (255, 255, 0)}

# Set the LEDs for each key in the current layer
for k in layers[current_layer].keys():
    keys[k].set_led(*colours[current_layer])

print("Starting!")
mode = 0
count = 0

# To prevent the strings (as opposed to single key presses) that are sent from 
# refiring on a single key press, the debounce time for the strings has to be 
# longer.

short_debounce = 0.03
long_debounce = 0.15
debounce = 0.03
fired = False

while True:
    # Always remember to call keybow.update()
    keybow.update()

    # if no key is pressed ensure not locked in layer change mode
    if ((mode == 2) & keybow.none_pressed()):
        mode = 0
        
    if modifier.held:
        # set to looking to change the keypad layer
        for layer in layers.keys():
            # If the modifier key is held, light up the layer selector keys
            if mode == 1:
                print("Looking for layer select")
                # Set the LEDs for each key in selectors
                for k in layer_keys:
                    keys[k].set_led(0, 0, 0)
                for k in selectors.keys():
                    keys[k].set_led(*colours[k])
                keys[0].set_led(0, 255, 0)
                mode = 2
            
            # Change current layer if layer key is pressed
            if selectors[layer].pressed:
                if mode >= 1:
                    mode = 0
                    current_layer = layer
                    print("Layer Changed:", current_layer)
                    # Set the LEDs for each key in the current layer
                    for k in layer_keys:
                        keys[k].set_led(0, 0, 0)
                    for k in layers[current_layer].keys():
                        keys[k].set_led(*colours[current_layer])
    else:
        # set to look for a key presses
        if mode == 0:
            print("Looking for key press on layer:", current_layer)
            mode = 1

            # Set the LEDs for each key in the current layer
            for k in layer_keys:
                keys[k].set_led(0, 0, 0)
            for k in layers[current_layer].keys():
                keys[k].set_led(*colours[current_layer])
                
    # Loop through all of the keys in the layer and if they're pressed, get the
    # key code from the layer's key map
    for k in layers[current_layer].keys():
        if keys[k].pressed:
            key_press = layers[current_layer][k]

            # If the key hasn't just fired (prevents refiring)
            if not fired:
                fired = True

                # Send the right sort of key press and set debounce for each
                # layer accordingly (layer 2 needs a long debounce)
                if (
                        (current_layer == 1) |
                        (current_layer == 4)
                ):
                    debounce = short_debounce
                    keyboard.send(key_press)
                elif current_layer == 2:
                    debounce = long_debounce
                    layout.write(key_press)
                elif current_layer == 3:
                    debounce = short_debounce
                    consumer_control.send(key_press)

    # If enough time has passed, reset the fired variable
    if fired and time.monotonic() - keybow.time_of_last_press > debounce:
        fired = False