Receiver

from microbit import *

MORSE_DECODE = {'.-': 'A', '-...': 'B', '-.-.': 'C',
    '-..': 'D', '.': 'E', '..-.': 'F',
    '--.': 'G', '....': 'H', '..': 'I',
    '.---': 'J', '-.-': 'K', '.-..': 'L',
    '--': 'M', '-.': 'N', '---': 'O',
    '.--.': 'P', '--.-': 'Q', '.-.': 'R',
    '...': 'S', '-': 'T', '..-': 'U',
    '...-': 'V', '.--': 'W', '-..-': 'X',
    '-.--': 'Y', '--..': 'Z',
    '-----': '0', '.----': '1', '..---': '2',
    '...--': '3', '....-': '4', '.....': '5',
    '-....': '6', '--...': '7', '---..': '8',
    '----.': '9'}

cur_letter = "" #current string of dits and dahs
cur_char = "" #current character to display
press_length = 0

while True:
    display.show(cur_char, wait=False)
    if pin0.read_analog() < 100: #string is being tugged
        press_length += 100
    elif press_length != 0: #string has been released
        if press_length < 600:
            cur_letter += "."
        elif press_length < 1200:
            cur_letter += "-"
        else: #letter complete
            if cur_letter in MORSE_DECODE.keys():
                cur_char = MORSE_DECODE[cur_letter]
            else:
                cur_char = "?"
    else:
        press_length = 0

    sleep(100)