Project 11: Morse Code

Morse code, also known as Morse password, is an on-again, off-again signal code that expresses different letters, numbers, and punctuation marks in different sequences. Now we use it as our password gate.

The Morse code corresponds to the following characters:

Project 11.1 Morse Code Open the Door

Description

We use \ as the correct password. What’s more, there is a button library file OneButton, which is very simple to click, double click, long press and other functions. For Morse password, click is “.”, long press and release is “-”.

Test Code

# Import machine, time and dht modules.
from machine import Pin, PWM
from time import sleep_ms, ticks_ms
from machine import SoftI2C, Pin
from i2c_lcd import I2cLcd

DEFAULT_I2C_ADDR = 0x27

# Initialize SCL/SDA pins and enable internal pull-up
scl_pin = Pin(22, Pin.OUT, pull=Pin.PULL_UP)  # GPIO22 with internal pull-up
sda_pin = Pin(21, Pin.OUT, pull=Pin.PULL_UP)  # GPIO21 with internal pull-up

i2c = SoftI2C(scl=Pin(22), sda=Pin(21), freq=100000)
lcd = I2cLcd(i2c, DEFAULT_I2C_ADDR, 2, 16)

button1 = Pin(16, Pin.IN, Pin.PULL_UP)
button2 = Pin(27, Pin.IN, Pin.PULL_UP)
count = 0
time_count = 0
password = ""   # Input password
correct_password = "-.-"  # Correct password
lcd.putstr("Enter password")
pwm = PWM(Pin(13))
pwm.freq(50)

while True:
    btnVal1 = button1.value()  # Reads the value of button 1
    if(btnVal1 == 0):
        sleep_ms(10)
        while(btnVal1 == 0):
            time_count = time_count + 1  # Start counting how long the button is pressed
            sleep_ms(200)                # Time accumulates in 200ms increments
            btnVal1 = button1.value()
            if(btnVal1 == 1):
                count = count + 1
                print(count)
                print(time_count)
                if(time_count > 3):      # If button pressed longer than 200*3ms, add "-" to password
                    lcd.clear()
                    #lcd.move_to(1, 1)
                    password = password + "-"
                else:
                    lcd.clear()
                    password = password + "."  # Otherwise add "."
                lcd.putstr('{}'.format(password))
                time_count = 0

    btnVal2 = button2.value()
    if(btnVal2 == 0):
        if(password == correct_password):  # If password is correct
            lcd.clear()
            lcd.putstr("open")
            pwm.duty(128)  # Open door
            password = ""  # Clear password
            sleep_ms(1000)
        else:              # If password is wrong
            lcd.clear()
            lcd.putstr("error")
            pwm.duty(25)  # Close door
            sleep_ms(2000)
            lcd.clear()
            lcd.putstr("enter again")
            password = ""  # Clear password

Test Result

At first, the LCD1602 displays “Enter password”, then click or long press button 1 to tap the password. If we input the correct password “-.-”, then click button 2, the door will open, and the LCD1602 will display “open”.

If other incorrect passwords are entered, the door will be closed and the LCD1602 will display error, which shows “enter again” 2s later.