gpiozero: A Raspberry Pi GPIO Control Library in Python

In the field of embedded development, the Raspberry Pi is a very popular development board. However, directly manipulating GPIO often requires handling many low-level details, which deters many developers. Until I encountered the gpiozero library, which made GPIO control so simple and elegant, it felt like writing poetry. I remember the first time I used it to control an LED; with just a few lines of code, I achieved a breathing light effect, which left a deep impression.

Installation and Configuration

The installation of gpiozero is very simple; just execute the following command on the Raspberry Pi:

pip install gpiozero

If you are developing on another computer and want to remotely control the Raspberry Pi’s GPIO, you also need to install pigpio:

pip install pigpio

After installation, you need to start the pigpio daemon:

sudo pigpiod

Basic Usage

The design philosophy of gpiozero is “simplicity first”. Taking LED control as an example:

from gpiozero import LED
from time import sleep

# Connect to LED on GPIO17
led = LED(17)

# Basic control
led.on()  # Turn on LED
sleep(1)
led.off()  # Turn off LED
sleep(1)

# Elegant blinking
led.blink()  # Automatically blink

Not only LED, button control is also very simple:

from gpiozero import Button

button = Button(2)

# Print message when button is pressed
button.when_pressed = lambda: print("Pressed")
button.when_released = lambda: print("Released")

Advanced Techniques

What amazes me most about gpiozero is its signal processing mechanism. You can create complex GPIO control flows using the source and values properties:

from gpiozero import PWMLED
from gpiozero.tools import sin_values
from signal import pause

# Create PWM LED
led = PWMLED(17)

# Use sine wave to control LED brightness, achieving a breathing light effect
led.source = sin_values()
pause()

The built-in utility functions also include:

• • scaled(): Scale value range

• • negated(): Invert value

• • all_values(): Combine multiple value sources

• • averaged(): Calculate average value

Practical Case

Let’s implement a simple smart doorbell system:

from gpiozero import Button, LED, Buzzer
from datetime import datetime
import threading
import time

class SmartDoorbell:
    def __init__(self):
        self.button = Button(2)
        self.status_led = LED(17)
        self.buzzer = Buzzer(3)
        
def ring_sequence(self):
        self.status_led.blink(on_time=0.1, off_time=0.1, n=5)
        self.buzzer.beep(on_time=0.1, off_time=0.1, n=5)
        
def button_pressed(self):
        print(f"Doorbell pressed - {datetime.now()}")
        threading.Thread(target=self.ring_sequence).start()
        
def run(self):
        self.button.when_pressed = self.button_pressed
        self.status_led.on()
        print("Smart doorbell system has started...")
        time.sleep(float('inf'))

if __name__ == "__main__":
    doorbell = SmartDoorbell()
    doorbell.run()

Summary and Outlook

The advantages of gpiozero are:

• • Simple and intuitive API design

• • Rich device support

• • Powerful signal processing mechanism

• • Comprehensive documentation and examples

However, there are some limitations:

• • Only supports Raspberry Pi platform

• • Some advanced features depend on pigpio

• • May not be suitable for scenarios with high real-time requirements

Looking ahead, with the development of the Internet of Things, libraries like gpiozero will play an increasingly important role. I look forward to seeing more developers create interesting projects with it. If you are developing with Raspberry Pi, I strongly recommend trying this excellent library; it will make your GPIO programming journey easy and enjoyable.