Controlling LED output

First IoT Program
Let’s write our first program to toggle a LED connected with GPIO pin on our virtual target. We are going to create a simple python program named hello-led.py with the following contents.
hello-led.py
import RPi.GPIO as GPIO    # Importing the GPIO controller module
import time
​
print("Hello LED")
ledPin = 9
​
print("Setting Broadcom Mode")
# Pin Setup:
GPIO.setmode(GPIO.BCM) # Broadcom pin-numbering scheme
​
#GPIO.setmode(GPIO.BOARD) ---> Board numbering scheme
​
print("Setting LED as an output")
GPIO.setup(ledPin, GPIO.OUT) 
​
print("Here we go! Press CTRL+C to exit")
try:
    while 1:
            print ("OFF");
            GPIO.output(ledPin, GPIO.LOW)
            time.sleep(1.00)
            print ("ON");            
            GPIO.output(ledPin, GPIO.HIGH)
            time.sleep(1) 
except KeyboardInterrupt: # If CTRL+C is pressed, exit cleanly
    GPIO.cleanup() # cleanup all GPIO
We have already downloaded the code at the folder hello-iot. To run this program on the target, open a command prompt from clicking the top left icon
and type following
cd hello-iot 
sudo python hello-led.py
The program will run in a loop and toggle the LED on PIN number 9. We switch the Webview tab to see the effect in action.
Press Ctrl+C to stop the program.
Congratulations! We now know how to control the GPIO pins.
Hello IoT - Previous
Introduction
Next - Hello IoT
Reading GPIO inputs
Last updated 7 months ago