# GPIO Zero library

The <mark style="color:blue;">GPIO Zero</mark> library offers a simplified approach to interact with the GPIO pins on a Raspberry Pi, providing an intuitive way to control external devices like LEDs, buttons, and sensors.&#x20;

This library abstracts the complex details of GPIO handling, making it accessible for beginners yet flexible enough for advanced users. Below is a summary of the basic recipes and best practices for using GPIO Zero in your projects:

#### <mark style="color:green;">**Importing GPIO Zero**</mark>

Before using GPIO Zero, you need to import the necessary classes. You can import specific components like `Button` or `LED`, or import the entire library.

```python
from gpiozero import Button
# or
import gpiozero
```

#### <mark style="color:green;">**Pin Numbering**</mark>

GPIO Zero uses Broadcom (BCM) pin numbering. You can also use physical (BOARD) numbering or other schemes by specifying prefixes.

```python
led = LED(17)  # Using BCM numbering
led = LED("BOARD11")  # Using physical numbering
```

#### <mark style="color:green;">**Basic Component Usage**</mark>

Here's how you can interact with basic components using GPIO Zero:

<mark style="color:purple;">**LED**</mark>

Turning an LED on and off:

```python
from gpiozero import LED
from time import sleep

red = LED(17)

while True:
    red.on()
    sleep(1)
    red.off()
    sleep(1)
```

<mark style="color:purple;">**Button**</mark>

<mark style="color:blue;">Detecting button presses</mark>

<pre class="language-python"><code class="lang-python">pfrom gpiozero import Button

<strong>button = Button(2)
</strong>
while True:
    if button.is_pressed:
        print("Button is pressed")
    else:
        print("Button is not pressed")
</code></pre>

#### <mark style="color:purple;">**Advanced Components and Usage**</mark>

GPIO Zero also supports more complex interactions, such as controlling traffic lights, reading from sensors, and controlling motors.

<mark style="color:blue;">**Traffic Lights**</mark>

Controlling a set of traffic lights:

```python
pythonCopy codefrom gpiozero import TrafficLights
from time import sleep

lights = TrafficLights(2, 3, 4)

while True:
    lights.green.on()
    sleep(10)
    lights.amber.on()
    sleep(1)
    lights.red.on()
    sleep(10)
    lights.off()  # Turn off all lights
```

<mark style="color:purple;">**Servo Motors**</mark>

<mark style="color:blue;">Controlling a servo motor:</mark>

```python
from gpiozero import Servo
from time import sleep

servo = Servo(17)

while True:
    servo.min()
    sleep(1)
    servo.mid()
    sleep(1)
    servo.max()
    sleep(1)
```

#### <mark style="color:purple;">**Interactive Projects**</mark>

GPIO Zero allows for creating interactive projects where components respond to input from sensors or buttons.

<mark style="color:purple;">**Button-Controlled LED**</mark>

<mark style="color:blue;">Turn an LED on and off using a button</mark>

```python
from gpiozero import LED, Button
from signal import pause

led = LED(17)
button = Button(2)

button.when_pressed = led.on
button.when_released = led.off

pause()
```

<mark style="color:purple;">**Robot**</mark>

Control a robot with basic movements:

```python
from gpiozero import Robot
from time import sleep

robot = Robot(left=(4, 14), right=(17, 18))

robot.forward()
sleep(5)
robot.right()
sleep(2)
robot.stop()
```

#### <mark style="color:blue;">**Best Practices**</mark>

* Keep your script running to maintain control over GPIOs, using `signal.pause()` or a loop that waits for an event.
* Clean up GPIO assignments at the end of your script to avoid conflicts on subsequent runs.
* Use `try...except...finally` blocks to handle exceptions and perform GPIO cleanup, ensuring that resources are released properly.

By following these guidelines and utilizing the GPIO Zero library, you can create a wide range of projects with your Raspberry Pi, from simple LED blinkers to complex interactive robots.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://education.raspberrypiaustralia.online/general-purpose-input-output-gpio/gpio-zero-library.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.