1. NUM_MAPS =[[1, 1, 1, 1, 1, 1, 0], #0
2.  [0, 1, 1, 0, 0, 0, 0], #1
3.  [1, 1, 0, 1, 1, 0, 1], #2
4.  [1, 1, 1, 1, 0, 0, 1], #3
5.  [0, 1, 1, 0, 0, 1, 1], #4
6.  [1, 0, 1, 1, 0, 1, 1], #5
7.  [1, 0, 1, 1, 1, 1, 1], #6
8.  [1, 1, 1, 0, 0, 0, 0], #7
9.  [1, 1, 1, 1, 1, 1, 1], #8
10.  [1, 1, 1, 1, 0, 1, 1]] #9
11. SEGMENT_PINS = [2,3,4,17,27,22,10]
12. import RPi.GPIO as GPIO
13. import time
14. GPIO.setmode(GPIO.BCM)
15. GPIO.setup(SEGMENT_PINS,GPIO.OUT)
16. def displayDigit(digit):
17.  if((digit < 0) or (digit > 9)):
18.  return
19.  for i in range(7):
20.  GPIO.output(SEGMENT_PINS[i],NUM_MAPS[digit][i]
21. )
22.  time.sleep(0.0005)
23.  GPIO.output(SEGMENT_PINS[i],GPIO.LOW)
24. num = 0;
25. counter = 0;
26. while (1):
27.  display4Digit(num);
28.  counter += 1
29.  if(counter == 200):
30.  counter = 0
31.  num += 1
32.  if(num > 9):
33.  num = 0;
34.  
35.  
36. import RPi.GPIO as GPIO
37. import time
38. KEY_MAPS = [[ '1', '2', '3', '4'],
39.  [ '5', '6', '7', '8'],
40.  [ '9','10','11','12'],
41.  ['13','14','15','16']];
42. COL_PINS = [0,1,2,3];
43. ROW_PINS = [4,5,6,7];
44. GPIO.setmode(GPIO.BCM)
45. GPIO.setup(COL_PINS,GPIO.OUT)
46. GPIO.setup(ROW_PINS,GPIO.IN)
47. def getKey():
48.  key = '\0';
49.  for i in range(4):
50.  GPIO.output(COL_PINS[i],GPIO.HIGH)
51.  for j in range(4):
52.  if(GPIO.input(ROW_PINS[j]) == 1):
53.  key = KEY_MAPS[j][i];
54.  time.sleep(0.250);
55.  GPIO.output(COL_PINS[i],GPIO.LOW)
56.  return key;
57. while(1):
58.  key = getKey()