morse.py

import time

characters = ""
started = False

morseAlphabet = {
    "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": "--..",
    " ": "....-",
    "/": "---...",
    "_": ".---."
}

morseAlphabet = dict((v, k) for (k, v) in morseAlphabet.items())

threshold = 200  # Theshold for sensor, greater than means it is active
# less than means it is not active

short_press = 90
long_press = 350
new_char = 1200
reset = 6000

queue = ""

started = False


def s():
    global queue
    queue += "."


def l():
    global queue
    queue += "-"


def get_value():
    v = ser.readline().strip()
    if v.isdigit():
        return int(v)
    else:
        return 0


while True:
    value = get_value()
    millis = int(round(time.time() * 1000))
    while value < threshold:  # Not active
        value = get_value()
        change = int(round(time.time() * 1000)) - millis
        if new_char < change:
            characters += morseAlphabet[queue]
            if characters[-1] == '_':
                characters = characters[:-2]
            queue = ""
            break
    if value > threshold:  # Active
        millis = int(round(time.time() * 1000))
        while value > threshold:
            value = get_value()
        change = int(round(time.time() * 1000)) - millis
        if short_press < change < long_press:
            s()
        elif long_press < change < reset:
            l()
        elif change > reset:
            characters = ""
            queue = ""