Button press detection in Raspberry Pi - Mini Project: Build & Apply

Button press detection

📖 Scenario: You have a Raspberry Pi connected to a physical button. When you press the button, the Raspberry Pi should detect the press and respond.

🎯 Goal: Build a simple program that detects when the button is pressed and prints a message.

📋 What You'll Learn

Use the gpiozero library to interact with the button.

Create a Button object connected to GPIO pin 2.

Detect when the button is pressed.

Print a message when the button is pressed.

💡 Why This Matters

🌍 Real World

Detecting button presses is common in physical computing projects like home automation, games, or interactive devices.

💼 Career

Understanding hardware input handling is useful for roles in embedded systems, IoT development, and robotics.

1

Set up the button

Import the Button class from the gpiozero library and create a button object connected to GPIO pin 2.

Raspberry Pi

# Import Button and create button on pin 2
# Your code here

Need a hint?

Use from gpiozero import Button and then button = Button(2).

2

Create a press handler

Define a function called on_press that prints "Button was pressed!" when called.

Raspberry Pi

from gpiozero import Button

button = Button(2)

# Define on_press function
# Your code here

Need a hint?

Define a function named on_press that prints the message.

3

Connect the handler to the button press

Assign the on_press function to the when_pressed property of the button object.

Raspberry Pi

from gpiozero import Button

button = Button(2)

def on_press():
    print("Button was pressed!")

# Connect on_press to button.when_pressed
# Your code here

Need a hint?

Use button.when_pressed = on_press to connect the function.

4

Keep the program running

Import pause from signal and call pause() to keep the program running and listening for button presses.

Raspberry Pi

from gpiozero import Button

button = Button(2)

def on_press():
    print("Button was pressed!")

button.when_pressed = on_press

# Import pause and call it to keep program running
# Your code here

Need a hint?

Use from signal import pause and then call pause() at the end.