Note

Hello, welcome to the SunFounder Raspberry Pi & Arduino & ESP32 Enthusiasts Community on Facebook! Dive deeper into Raspberry Pi, Arduino, and ESP32 with fellow enthusiasts.

Why Join?

Expert Support: Solve post-sale issues and technical challenges with help from our community and team.
Learn & Share: Exchange tips and tutorials to enhance your skills.
Exclusive Previews: Get early access to new product announcements and sneak peeks.
Special Discounts: Enjoy exclusive discounts on our newest products.
Festive Promotions and Giveaways: Take part in giveaways and holiday promotions.

👉 Ready to explore and create with us? Click [here] and join today!

Lesson 30: Relay Module

In this lesson, you will learn how to control a relay module using a Raspberry Pi. You’ll learn how to write a simple Python script to turn the relay on and off at one-second intervals. This project is a practical introduction to using GPIO pins for controlling external devices, providing a basic understanding of how relays work in electronic circuits. It’s a straightforward and informative exercise, well-suited for beginners starting with Raspberry Pi and hardware control.

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name	ITEMS IN THIS KIT	LINK
Universal Maker Sensor Kit	94	Universal Maker Sensor Kit

You can also buy them separately from the links below.

Component Introduction	Purchase Link
Raspberry Pi 5	BUY
5V Relay Module	-
RGB LED Module	-
Breadboard	BUY

Wiring

Code

from gpiozero import OutputDevice
from time import sleep

# Replace with your GPIO pin number
relay_pin = 17  # Example using GPIO17

# Initialize relay object
relay = OutputDevice(relay_pin)

try:
   while True:
      # Turn on the relay
      relay.on()
      sleep(1)  # Relay remains on for 1 second

      # Turn off the relay
      relay.off()
      sleep(1)  # Relay remains off for 1 second

except KeyboardInterrupt:
   # Capture Ctrl+C and safely close the program
   relay.off()
   print("Program interrupted by user")

Code Analysis

Import Libraries

Import the gpiozero library for GPIO control and the time library for delays.
```
from gpiozero import OutputDevice
from time import sleep
```
Initialize the Relay

Define the GPIO pin connected to the relay and initialize an OutputDevice object with that pin.
```
relay_pin = 17  # Example using GPIO17
relay = OutputDevice(relay_pin)
```

Relay Control in a Loop

The while True: loop continuously toggles the relay. relay.on() and relay.off() are used to control the relay, and sleep(1) creates a one-second delay between each state.

try:
    while True:
        relay.on()
        sleep(1)  # Relay remains on for 1 second
        relay.off()
        sleep(1)  # Relay remains off for 1 second

Exception Handling

The except block captures a KeyboardInterrupt (Ctrl+C). It ensures the relay is turned off and the program exits safely.
```
except KeyboardInterrupt:
    relay.off()
    print("Program interrupted by user")
```