code.py

import board
import busio
import time
from digitalio import DigitalInOut, Direction, Pull
from adafruit_debouncer import Debouncer
import usb_hid
from adafruit_hid.keyboard import Keyboard
# Import the keyboard layout description
from adafruit_hid.keyboard_layout_uk import KeyboardLayoutUK

from adafruit_hid.keycode import Keycode
from Adafruit-ST7735-Library import adafruit_7789

version = "1.1"
# Make this false for a left-handed keyboard
RIGHT_HANDED = False

class Switch:
    def __init__(self, pin, bit)  :
        self.pin = pin
        self.bit = bit

class Key():
    def __init__(self, keyboard, switch): 
        self.keyboard = keyboard
        self.bit = switch.bit
        # make a digital io from the pin
        io = DigitalInOut(switch.pin)
        # add a pullup
        io.pull = Pull.UP
        # create the key debouncer
        self.debounce = Debouncer(io,interval=0.01)
        self.debounce.update()
        self.pressed = not self.debounce.value
        self.guide_key=False

    def update(self):
        debounce = self.debounce
        debounce.update()
        if debounce.fell:
            self.key_down()
        if debounce.rose:
            self.key_up()
           
            
    def key_down(self):
        keyboard = self.keyboard
        self.pressed = True
        if keyboard.character_bits == 0:
            # this is the first press of a new character
            keyboard.assembling_bits = True
        keyboard.character_bits = keyboard.character_bits + self.bit
    
    def key_up(self):
        keyboard = self.keyboard
        self.pressed = False
        # get the current bits value
        bits = keyboard.character_bits
        # clear this bit from the keyboard
        keyboard.character_bits = keyboard.character_bits - self.bit
        if keyboard.assembling_bits:
            # This is the first key up - we have a char
            keyboard.assembling_bits = False
            keyboard.got_bits(bits)
            
class Processor:

    def __init__(self, keyboard): 
        self.keys = keyboard

class TextProcessor(Processor):

    def __init__(self, keyboard): 
        super(TextProcessor,self).__init__(keyboard)

    def start(self):
        self.keys.display_text("")
        self.keys.start_lower_case_text()

    def key_pressed(self,key):
        print("Key pressed text:", key)
        self.keys.display_text(key)
        self.keys.usb_layout.write(key)
        
    def update(self):
        pass

class HelpProcessor(Processor):

    def __init__(self, keyboard): 
        super(HelpProcessor,self).__init__(keyboard)

    def start(self):
        print("Start help")
        self.keys.set_keyboard_state(PicoChord.LOWER_CASE_KEYS)
        self.keys.clear_all_keys()    
        self.keys.scroll_text("Printing help. Hold any key to stop")
        self.mode=PicoChord.HELP_MODE
        time.sleep(2.0) 
        self.text_waiting_for_clear_keys = True
        self.test_count=0
        
    def key_pressed(self,key):
        print("Key pressed help:", key)

    def print_stop_check(self):
        self.keys.update_keys()
        if self.keys.character_bits != 0:
            return True

    def update(self):
        if self.text_waiting_for_clear_keys:
            if self.keys.character_bits == 0:
                # all the keys are up, we can start the output
                self.game_waiting_for_clear_keys = False
                self.keys.print_keys()
                self.keys.scroll_text("Help complete")
                self.keys.set_keyboard_state(PicoChord.LOWER_CASE_KEYS)
                self.keys.clear_all_keys()
                self.keys.clear_keyboard_guides()
                self.keys.start_mode(PicoChord.TEXT_MODE)
              

class GameProcessor(Processor):

    def __init__(self, keyboard, test_texts): 
        super(GameProcessor,self).__init__(keyboard)
        self.keys.game_help_displayed = False
        self.test_texts = test_texts

    def get_test_char(self):
        test_string = self.test_texts[self.game_test_strings_pos]
        return test_string[self.game_txt_pos]
    
    def game_step_start(self):
        ch = self.get_test_char()
        self.keys.display_text(ch)
        self.game_step_start_time = time.monotonic()
        self.game_help_display_time = self.game_step_start_time + self.game_display_time
        self.keys.clear_keyboard_guides()
        self.keys.game_help_displayed = False
        
    def game_step_advance_char(self):
        test_string = self.test_texts[self.game_test_strings_pos]
        self.game_txt_pos = self.game_txt_pos + 1
        if self.game_txt_pos == len(test_string):
            self.game_txt_pos = 0
            self.game_test_strings_pos = self.game_test_strings_pos + 1
            if self.game_test_strings_pos == len(self.test_texts):
                self.game_test_strings_pos = 0

    def start(self):
        print("Start game")
        self.keys.set_keyboard_state(PicoChord.LOWER_CASE_KEYS)
        self.keys.clear_all_keys()     
        self.keys.scroll_text("Game starting.....")
        time.sleep(2.0)
        self.keys.mode=PicoChord.GAME_MODE
        self.game_display_time = 1.0
        self.game_txt_pos = 0
        self.game_test_strings_pos = 0
        self.game_score = 0
        self.game_waiting_for_clear_keys = True
        
    def key_pressed(self,key):
        print("Key pressed game:", key)
        if key == self.get_test_char():
            if self.keys.game_help_displayed:
                self.game_score = self.game_score + 1
            else:
                self.game_score = self.game_score + 5
            self.game_step_advance_char()
            self.game_step_start()
        else:
            score_message = "Game over score " + str(self.game_score)
            self.keys.scroll_text(score_message)
            time.sleep(5)
            self.keys.clear_keyboard_guides()
            self.keys.start_mode(PicoChord.TEXT_MODE)

    def update(self):
        if self.game_waiting_for_clear_keys:
            if self.keys.character_bits == 0:
                # all the keys are up, we can start the game
                self.game_step_start()
                self.game_waiting_for_clear_keys = False
        else:
            current_time = time.monotonic()
            if not self.keys.game_help_displayed:
                if current_time > self.game_help_display_time:
                    self.keys.display_guide(self.get_test_char())
                    self.keys.game_help_displayed = True

class PicoChord:
    
    UPPER_CASE_KEYS=0
    LOWER_CASE_KEYS=1
    NUMBER_KEYS=2
    SYMBOL_KEYS=3

    
    def set_keyboard_state(self,state):
        self.keyboard_state = state
        return
        
    def get_keyboard_col(self):
        return PicoChord.keyboard_state_cols[self.keyboard_state]
        
    def do_toggle_caps_lock(self):
        print("Caps lock toggle",self.mode)
        if self.keyboard_state == PicoChord.UPPER_CASE_KEYS:
            self.set_keyboard_state(PicoChord.LOWER_CASE_KEYS)
            return
        if self.keyboard_state == PicoChord.LOWER_CASE_KEYS:
            self.set_keyboard_state(PicoChord.UPPER_CASE_KEYS)
            return

    def display_text(self, text):
        self.display.fill(0)
        self.display.print(text)
        
    def scroll_text(self,text):
        self.display.marquee(text, delay=0.25, loop=False)
        
    TEXT_MODE = 0
    HELP_MODE = 1
    GAME_MODE = 2

    # text behaviours

    def start_lower_case_text(self):
        print("Start lower case text")
        self.set_keyboard_state(PicoChord.LOWER_CASE_KEYS)

    def start_upper_case_text(self):
        print("Start upper case text")
        self.set_keyboard_state(PicoChord.UPPER_CASE_KEYS)

    def start_number_text(self):
        print("Start number text")
        self.set_keyboard_state(PicoChord.NUMBER_KEYS)

    def start_symbol_text(self):
        print("Start symbol text")
        self.set_keyboard_state(PicoChord.SYMBOL_KEYS)

    test_texts = (
        "abcdefghijklmnopqrstuvwxyz",
        "the quick brown fox jumps over the lazy dog",
        "Jackdaws love my big sphinx of quartz.",
        "The five boxing wizards jump quickly.",
        "A Capital Idea",
        "1234567890",
        "I am 21 years old",
        "if a<b print(\"hello\")"
        )

    # Check to see if the bits contain a command and perform 
    # the command if they do
    def check_command(self,bits):
        if bits in self.command_actions:
            # Got a control code
            command = self.command_actions[bits]
            name = command[0]
            function = command[1]
            print("Control:",name)
            function(self)

    def got_bits(self, bits):
        # got a bit pattern - need to act on the bits
        print("Bits:",bits)
        # get the decode array we need
        decode = self.state_decodes[self.keyboard_state]
        # decide the pattern to get the key pressed
        if not bits in decode:
            # Check for a control character at this position
            self.check_command(bits)
            return
        # Have a character key            
        key = decode[bits]
        # Check for upper case
        if self.keyboard_state == PicoChord.UPPER_CASE_KEYS:
            key = key.upper()
        processor = self.mode_processors[self.mode]
        processor.key_pressed(key)   

    def clear_keyboard_guides(self):
        for key in self.keys:
            key.guide_key=False

    def get_key_bits(self):
        if RIGHT_HANDED:
            bits = (1,2,4,8,16,32)
        else:
            bits = (32,16,8,4,2,1)
        return bits

    def display_guide(self, ch): 
        char_def = self.lookup_character(ch)
        ch = char_def[0]
        char_bits = char_def[1]
        char_state = char_def[2]
        up_col = self.keyboard_state_cols[char_state]
        pos = 0
        for bit in self.get_key_bits():
            key = self.keys[pos]
            if (char_bits & bit) == 0:
                key.guide_key = False
            else:
                key.guide_key = True
            pos = pos + 1
        
    def display_keypress(self, char_def, col): 
        ch = char_def[0]
        char_bits = char_def[1]
        char_state = char_def[2]
        pos = 0
        for bit in self.get_key_bits():
            key = self.keys[pos]

    def display_char_on_keyboard(self,ch):
        char_def = self.lookup_character(ch)
        if char_def != None:
            print('Displaying:',char_def)
            self.display_keypress(char_def)
        
    def send_animated_text_to_keyboard(self,text):
        old_state = self.keyboard_state
        for ch in text:
            self.display_text(ch)
            self.display_char_on_keyboard(ch,self.key_down_col)
            self.pixels.show()
            self.usb_layout.write(ch)
            time.sleep(0.1)
        self.keyboard_state=old_state
        self.display_text("")
        self.usb_kbd.send(Keycode.ENTER)
        self.set_keyboard_state(old_state)

    def print_key(self,symbol,bits):
        print("Printing:",symbol,bits)
        self.send_animated_text_to_keyboard(symbol)
        
        if RIGHT_HANDED:
            top_line = "        "
            bottom_line = ""
            for bit in (1,2,4,8,16,32):
                if (bits & bit) == 0:
                    text="[ ] "
                else:
                    text="[X] "
                if bit < 4:
                    bottom_line = bottom_line + text
                else:
                    top_line = top_line + text
        else:
            top_line = ""
            bottom_line = "                "
            for bit in (32,16,8,4,2,1):
                if (bits & bit) == 0:
                    text="[ ] "
                else:
                    text="[X] "
                if bit < 4:
                    bottom_line = bottom_line + text
                else:
                    top_line = top_line + text
        self.send_animated_text_to_keyboard(top_line)
        self.send_animated_text_to_keyboard(bottom_line)
        self.send_animated_text_to_keyboard("-----------------------")
        
    def print_decode(self,title, decode_dict):
        if self.help_proc.print_stop_check():
            return
        self.send_animated_text_to_keyboard(title)
        for item in sorted(decode_dict.items(),key=lambda x:x[1]):
            bits = item[0]
            symbol = item[1]
            self.print_key(symbol,bits)
            if self.help_proc.print_stop_check():
                return

    def print_control(self,title, decode_dict):
        if self.help_proc.print_stop_check():
            return
        self.send_animated_text_to_keyboard(title)
        for item in sorted(decode_dict.items(),key=lambda x:x[1][0]):
            bits = item[0]
            symbol = item[1][0]
            description = item[1][0] + " : " + item[1][2]
            self.print_key(description,bits)
            if self.help_proc.print_stop_check():
                return
            
    def build_reverse_lookup(self,key_lookup_dict):
        result = {}
        for item in key_lookup_dict.items():
            bits = item[0]
            symbol = item [1]
            result[symbol]=bits
        return result
        
    def build_reverse_lookups(self):
        self.text_reverse_lookup = self.build_reverse_lookup(self.text_decode)
        self.num_reverse_lookup = self.build_reverse_lookup(self.num_decode)
        self.sym_reverse_lookup = self.build_reverse_lookup(self.sym_decode)
        
    def lookup_character(self,ch):
        low_ch = ch.lower()
        if low_ch in self.text_reverse_lookup:
            bits = self.text_reverse_lookup[low_ch]
            if low_ch == ch:
                # char is lower case
                state = PicoChord.LOWER_CASE_KEYS
            else:
                state = PicoChord.UPPER_CASE_KEYS
            return (ch,bits,state)
        if ch in self.num_reverse_lookup:
            bits = self.num_reverse_lookup[ch]
            return (ch,bits,PicoChord.NUMBER_KEYS)
        if ch in self.sym_reverse_lookup:
            bits = self.sym_reverse_lookup[ch]
            return (ch,bits,PicoChord.SYMBOL_KEYS)
        return None
        
    def get_command(self,name, commands):
        self.send_text_to_keyboard(name)
        key_no = 0
        command_keys = []
        self.pixels.fill(Col.BLACK)
        for command in commands:
            col = command[0]
            text = command[1]
            self.send_text_to_keyboard(Col.names[col]+' : '+text)
            key = self.keys[key_no]
            self.pixels[key.pixel]=col
            key_no = key_no+1
        self.pixels.show()
        self.wait_for_all_keys_up()
        while True:
            for pos in range(0,key_no):
                key = self.keys[pos]
                debounce = key.debounce
                debounce.update()
                if debounce.fell:
                    return commands[pos][0]
        
    def start_mode(self,mode):
        self.mode = mode
        processor = self.mode_processors[self.mode]
        processor.start()

    def handle_text_control(self):
        # If we are in game mode we are using
        # the text command to switch to text symbol types
        if self.mode == PicoChord.GAME_MODE:
            self.start_lower_case_text()
        else:
            self.start_mode(PicoChord.TEXT_MODE)

    def print_keys(self):
        self.print_decode("Text",self.text_decode) 
        self.print_decode("Numbers",self.num_decode) 
        self.print_decode("Symbols", self.sym_decode) 
        self.print_control("Control",self.command_actions)

    def __init__(self,i2c_sda,i2c_scl,key_switches):
        hello_message = "PICO Chord " + str(version)
        print(hello_message)
        #
        self.usb_kbd = Keyboard(usb_hid.devices)
        # Set the required keyboard layout
        self.usb_layout = KeyboardLayoutUK(self.usb_kbd)
        #
        # Make i2c connection
        self.i2c = busio.I2C(i2c_scl, i2c_sda)
        # Make display
        self.display = segments.Seg14x4(self.i2c)
        self.scroll_text(hello_message)
        # Create the array of keys
        self.keys = []
        # going to use a mask bit for each key to assemble a key pattern
        for switch in key_switches:
            # Make the key
            key = Key(keyboard=self,switch=switch)
            # add it to the list of keys
            self.keys.append(key)

        self.text_decode = {
            12:'a', 56:'b', 10:'c', 14:'d', 4:'e', 30:'f', 48:'g', 34:'h',
            6:'i', 50:'j', 18:'k', 38:'l', 60:'m', 24:'n', 8:'o', 62:'p',
            40:'q', 22:'r', 16:'s', 20:'t', 32:'u', 36:'v', 54:'w', 58:'x',
            26:'y', 42:'z', 2:' ', 52:',',  28:'.'}
        
        self.num_decode = {
            8:'0', 2:'1', 6:'2', 14:'3', 30:'4', 62:'5', 32:'6', 48:'7',
            56:'8', 60:'9', 52:',',  28:'.'
            }
            
        self.sym_decode = {
            2:' ', 52:',',  28:'.', 54:':', 50:';', 42:'%', 4:'=', 22:'&',
            14:'(', 56:')', 16:'$', 12:'@', 62 :'+', 34:'#' ,
            24:'-', 58 :'!', 26:'?', 18:'/',30:'{',60:'}',
            10:'[', 40:']',36:'\\',20:'*',6:'<',48:'>'
            }
        
        self.build_reverse_lookups()
        #                         upper             lower            numbers          symbols
        self.state_decodes = (self.text_decode, self.text_decode, self.num_decode, self.sym_decode)

        self.command_actions = {
            1: ("caps", lambda x:self.do_toggle_caps_lock(),"Toggle CAPS lock"),
            13:("del", lambda x:self.usb_kbd.send(Keycode.BACKSPACE),"Backspace and delete"),
            17:("sym", lambda x:self.set_keyboard_state(PicoChord.SYMBOL_KEYS),"Set symbol mode (magenta)"),
            21:("text", lambda x:self.handle_text_control(),"Set text mode (blue)"),
            25:("num", lambda x:self.start_number_text(),"Set numeric mode (green)"),
            29:("for", lambda x:self.usb_kbd.send(Keycode.RIGHT_ARROW),"Move cursor right"),
            44:("ret", lambda x:self.usb_kbd.send(Keycode.ENTER),"Enter key"),
            57:("bak", lambda x:self.usb_kbd.send(Keycode.LEFT_ARROW),"Move cursor left"),
            33:("Help", lambda x:self.start_mode(PicoChord.HELP_MODE), "Type help information"),
            49:("Game", lambda x:self.start_mode(PicoChord.GAME_MODE), "Start the game")
            }

        test_texts = (
            "abcdefghijklmnopqrstuvwxyz",
            "the quick brown fox jumps over the lazy dog",
            "Jackdaws love my big sphinx of quartz.",
            "The five boxing wizards jump quickly.",
            "A Capital Idea",
            "1234567890",
            "I am 21 years old",
            "if a<b print(\"hello\")"
            )

        self.game_proc = GameProcessor(self,test_texts)
        self.text_proc = TextProcessor(self)
        self.help_proc = HelpProcessor(self)

        self.mode_processors = {
                PicoChord.TEXT_MODE:self.text_proc,
                PicoChord.HELP_MODE:self.help_proc,
                PicoChord.GAME_MODE:self.game_proc
        }
        
        self.wait_for_all_keys_up()
        self.character_bits=0
        self.assembling_bits = False
        self.mode = PicoChord.TEXT_MODE
        self.start_mode(PicoChord.TEXT_MODE)

        self.pixels.show()
        
    def key_down(self):
        for key in self.keys:
            # get the key debouncer
            debounce = key.debounce
            debounce.update()
            if not debounce.value:
                return True
        return False
        
    def wait_for_all_keys_up(self):
        while True:
            if self.key_down():
                continue
            return
        
    def test(self):
        self.display.print("Test")        
        while True:
            # scan the keyboard and turn pressed keys red
            for key in self.keys:
                # get the key debouncer
                debounce = key.debounce
                # get the key number
                bit = key.bit
                debounce.update()
                if debounce.fell:
                    print("Key down:", bit)
                    self.pixels[key.pixel]=Col.RED
                    self.display.fill(0)
                    self.display.print(f"D{bit}")
                if debounce.rose:
                    print("Key up:", bit)
                    self.pixels[key.pixel]=Col.GREY
                    self.display.fill(0)
                    self.display.print(f"U{bit}")
            self.pixels.show()
    
    def update_keys(self):
        for key in self.keys:
            key.update()
    
    def update(self):
        self.update_keys()
        processor = self.mode_processors[self.mode]
        processor.update()
        self.pixels.show() 
        
    def run(self):
        while True:
            self.update()

if RIGHT_HANDED:
    key_switches=[
        Switch(pin=board.GP15,pixel=0,bit=1),  # control
        Switch(pin=board.GP14,pixel=1,bit=2),  # thumb
        Switch(pin=board.GP13,pixel=2,bit=4),  # index
        Switch(pin=board.GP12,pixel=3,bit=8),  # middle
        Switch(pin=board.GP11,pixel=4,bit=16), # ring
        Switch(pin=board.GP10,pixel=5,bit=32)  # little
        ]
else:
    key_switches=[
        Switch(pin=board.GP15,pixel=0,bit=32),  # control
        Switch(pin=board.GP14,pixel=1,bit=16),  # thumb
        Switch(pin=board.GP13,pixel=2,bit=8),  # index
        Switch(pin=board.GP12,pixel=3,bit=4),  # middle
        Switch(pin=board.GP11,pixel=4,bit=2), # ring
        Switch(pin=board.GP10,pixel=5,bit=1)  # little
        ]
keyboard = PicoChord(i2c_sda=board.GP0, i2c_scl=board.GP1,
            pixel_pin=board.GP17,
            key_switches=key_switches)
keyboard.run()