Python on Raspberry Pi - Mini Project: Build & Apply

Python on Raspberry Pi: Controlling an LED

📖 Scenario: You have a Raspberry Pi with an LED connected to GPIO pin 17. You want to write a Python program to turn the LED on and off.

🎯 Goal: Build a Python program that sets up the GPIO pin, turns the LED on, waits, then turns it off.

📋 What You'll Learn

Create a variable called led_pin and set it to 17

Create a variable called delay_time and set it to 2

Use GPIO.setup(led_pin, GPIO.OUT) to set the pin as output

Use GPIO.output(led_pin, GPIO.HIGH) to turn the LED on

Use GPIO.output(led_pin, GPIO.LOW) to turn the LED off

Print "LED is ON" when the LED turns on

Print "LED is OFF" when the LED turns off

💡 Why This Matters

🌍 Real World

Controlling hardware like LEDs, motors, and sensors with Python on a Raspberry Pi is common in home automation and robotics projects.

💼 Career

Understanding GPIO control with Python is useful for roles in embedded systems, IoT development, and hardware prototyping.

1

Set up the GPIO pin variable

Create a variable called led_pin and set it to 17.

Raspberry Pi

# Your code here

Need a hint?

Use led_pin = 17 to store the GPIO pin number.

2

Set the delay time variable

Create a variable called delay_time and set it to 2.

Raspberry Pi

led_pin = 17
# Your code here

Need a hint?

Use delay_time = 2 to set the wait time in seconds.

3

Set up GPIO and turn LED on

Import RPi.GPIO as GPIO, set the GPIO mode to GPIO.BCM, set up led_pin as output using GPIO.setup(led_pin, GPIO.OUT), then turn the LED on with GPIO.output(led_pin, GPIO.HIGH). Also, print "LED is ON".

Raspberry Pi

led_pin = 17
delay_time = 2
# Your code here

Need a hint?

Remember to import the GPIO library and set the mode before setting up the pin.

4

Turn LED off after delay and clean up

Use time.sleep(delay_time) to wait, then turn the LED off with GPIO.output(led_pin, GPIO.LOW). Print "LED is OFF" and call GPIO.cleanup() to reset the pins. Finally, print the messages exactly as shown.

Raspberry Pi

import RPi.GPIO as GPIO
import time

led_pin = 17
delay_time = 2

GPIO.setmode(GPIO.BCM)
GPIO.setup(led_pin, GPIO.OUT)
GPIO.output(led_pin, GPIO.HIGH)
print("LED is ON")
# Your code here

Need a hint?

Use time.sleep(delay_time) to wait, then turn off the LED and clean up.