Read/Write GPIO of Raspberry Pi 2 using Python

This example show how to read button on GPIO 20 and turn ON/OFF LED on GPIO 21 accordingly, for Raspberry Pi 2 using Python.


Connection:

testGPIO.py

import sys
import RPi.GPIO as GPIO
import time

print("sys.version:")
print(sys.version + "\n")

print("GPIO.VERSION: " + GPIO.VERSION)
print("GPIO.RPI_INFO['P1_REVISION'] = " + str(GPIO.RPI_INFO['P1_REVISION']));

io20 = 20
io21 = 21

GPIO.setmode(GPIO.BCM)
GPIO.setup(io20, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(io21, GPIO.OUT)

print("Press button to turn ON LED");
try:
    while(True):
        if (GPIO.input(io20)):
            GPIO.output(io21, GPIO.LOW)
        else:
            GPIO.output(io21, GPIO.HIGH)
    
except KeyboardInterrupt:
    print ("\n")
    print ("Exit by KeyboardInterrupt\n")
  
except:
    print ("\n")
    print ("Exit by Other case!\n")
  
finally:  
    GPIO.cleanup(io20)
    GPIO.cleanup(io21)
    print ("Clean up GPIO\n")

More Python examples for Raspberry Pi/Raspberry Pi 2:
- Control RPi.GPIO PWM
- Make a hardware button to shutdown Raspberry Pi