#!/usr/bin/env python3

import RPi.GPIO as GPIO
import Keypad       #import module Keypad
ROWS = 4        # number of rows of the Keypad
COLS = 4        #number of columns of the Keypad
keys =  [   '1','2','3','A',    #key code
            '4','5','6','B',
            '7','8','9','C',
            '*','0','#','D'     ]
rowsPins = [12,16,18,22]        #connect to the row pinouts of the keypad
colsPins = [19,15,13,11]        #connect to the column pinouts of the keypad

def loop():
    keypad = Keypad.Keypad(keys,rowsPins,colsPins,ROWS,COLS)    #creat Keypad object
    keypad.setDebounceTime(50)      #set the debounce time
    while(True):
        key = keypad.getKey()       #obtain the state of keys
        if(key != keypad.NULL):     #if there is key pressed, print its key code.
            print ("You Pressed Key : %c "%(key))
            
if __name__ == '__main__':     #Program start from here
    print ("Program is starting ... ")
    try:
        loop()
    except KeyboardInterrupt:  #When 'Ctrl+C' is pressed, exit the program. 
        GPIO.cleanup()