python_gpio.py

gistfile1.txt

import RPi.GPIO as GPIO
import time


st = 1 # sleep time
def preamable(pin):
    for _ in range(0,8):
        blink(pin)  # blink 0.5s
        time.sleep(st) #dim 0.5s
    return


def all_one(pin):
    for _ in range(0,8):
        blink(pin)
    return

def decode(msg):
    
    msg_list =  []
    for c in msg:
        a = bin(ord(c)) # change c to ASCII int ord and bin format str
        a =  a.replace('0b','')
        
        while len(a) < 8: # append to 8-bits format
            a = '0' + a
        print(a)
        msg_list.append(a)
    
    
    return msg_list


# blink_msg in byte format
def blink_msg(msg_list,pin):
    
    for msg in msg_list:
        for i in msg :
            if i == '0':
                time.sleep(st)
            else :
                blink(pin)
    return


# blinking one bit signal function
def blink(pin):
    GPIO.output(pin,GPIO.HIGH)
    time.sleep(st) #light 0.1 sec
    GPIO.output(pin,GPIO.LOW)
    #time.sleep(0.01)
    # dim 0.01 sec
    return

def main():
    GPIO.cleanup()
    
    msg = input("Type the message: ")
    
    #decode(msg)
# to use Raspberry Pi board pin numbers
    GPIO.setmode(GPIO.BCM) # choose Bcm for convinent
# set up GPIO output channel, we set GPIO4 (Pin 22) to OUTPUT
    GPIO.setup(22, GPIO.OUT)
    preamable(22)

    if len(bytearray(msg.encode(encoding='utf-8'))) < 10:
        blink_msg(decode( '0' + str(len(bytearray(msg.encode(encoding='utf-8'))))),22) # exp : len(msg) = 2 send '02'
    else :
        blink_msg(decode(str(len(bytearray(msg.encode(encoding='utf-8'))))),22) # exp : len(msg) = 2 send '02'
    
    bytes_arr = bytearray(msg.encode(encoding='utf-8'))
    blink_msg([bin(v)[2:].zfill(8) for v in bytes_arr],22)
    
    GPIO.cleanup()
    
    
if __name__ == '__main__':
    main()