NUM_MAPS =[[1, 1, 1, 1, 1, 1, 0], #0
 [0, 1, 1, 0, 0, 0, 0], #1 
 [1, 1, 0, 1, 1, 0, 1], #2
 [1, 1, 1, 1, 0, 0, 1], #3
 [0, 1, 1, 0, 0, 1, 1], #4
 [1, 0, 1, 1, 0, 1, 1], #5
 [1, 0, 1, 1, 1, 1, 1], #6
 [1, 1, 1, 0, 0, 0, 0], #7
 [1, 1, 1, 1, 1, 1, 1], #8
 [1, 1, 1, 1, 0, 1, 1]] #9
SEGMENT_PINS = [2,3,4,17,27,22,10] 
import RPi.GPIO as GPIO
import time
GPIO.setmode(GPIO.BCM) 
GPIO.setup(SEGMENT_PINS,GPIO.OUT) 
def displayDigit(digit): 
 if((digit < 0) or (digit > 9)): 
 return
 for i in range(7): 
 GPIO.output(SEGMENT_PINS[i],NUM_MAPS[digit][i]
) 
 time.sleep(0.0005) 
 GPIO.output(SEGMENT_PINS[i],GPIO.LOW) 
num = 0;
counter = 0;
while (1): 
 display4Digit(num);
 counter += 1
 if(counter == 200): 
 counter = 0
 num += 1
 if(num > 9): 
 num = 0;


import RPi.GPIO as GPIO 
import time 
KEY_MAPS = [[ '1', '2', '3', '4'], 
 [ '5', '6', '7', '8'], 
 [ '9','10','11','12'], 
 ['13','14','15','16']];
COL_PINS = [0,1,2,3];
ROW_PINS = [4,5,6,7];
GPIO.setmode(GPIO.BCM) 
GPIO.setup(COL_PINS,GPIO.OUT) 
GPIO.setup(ROW_PINS,GPIO.IN) 
def getKey(): 
 key = '\0';
 for i in range(4): 
 GPIO.output(COL_PINS[i],GPIO.HIGH) 
 for j in range(4): 
 if(GPIO.input(ROW_PINS[j]) == 1): 
 key = KEY_MAPS[j][i];
 time.sleep(0.250);
 GPIO.output(COL_PINS[i],GPIO.LOW) 
 return key;
while(1): 
 key = getKey()