Tutorial 3 - Button Input

Introduction

Push buttons are one of the most common ways for a user to provide input. In this tutorial, you will connect a button to the Raspberry Pi 5 and use it to control an LED.

Components Needed

Component	Quantity
Raspberry Pi 5	1
Breadboard	1
Wires	Several
LED	1
300 - 1K Ohm Resistor	1

Image credit: SunFounder

Fritzing Diagram

Connect the button and LED to your Raspberry Pi as shown in the following diagram.

Image credit: SunFounder

Code

from gpiozero import LED, Button
from time import sleep

# Initialize an LED connected to GPIO pin 17 and a button connected to GPIO pin 18
led = LED(17)
button = Button(18)

# Keep track of the LED state
led_status = False

print("Press the button to toggle the LED. Press Ctrl+C to exit.")
while True:
    if button.is_pressed:
        led_status = not led_status
        if led_status:
            led.on()
            print('LED ON')
        else:
            led.off()
            print('LED OFF')
        sleep(0.5)

Code Explanation

from gpiozero import LED, Button
from time import sleep

This imports the LED and Button classes from gpiozero, plus sleep from the standard time module.

led = LED(17)
button = Button(18)

These lines configure the LED on GPIO 17 and the button on GPIO 18.

led_status = False

This variable keeps track of whether the LED is currently on or off.

while True:

The loop runs continuously so the Raspberry Pi keeps checking the button state.

if button.is_pressed:

This checks whether the button is currently pressed.

led_status = not led_status

This toggles the LED state each time the button is pressed.

sleep(0.5)

The short delay helps debounce the button so one press does not trigger multiple toggles.

Conclusion

This example shows how to use a button as digital input and react to that input by changing the state of an LED.