Raspberry Pi - Fan

This tutorial instructs you how to use Raspberry Pi to control a fan. A different tutorial will be devoted to controlling the speed of the fan.

Hardware Preparation

1×Raspberry Pi 4 Model B
1×Relay
1×12V DC Cooling Fan
1×(Alternative) 5V DC Cooling Fan
1×12V Power Adapter
1×DC Power Jack
1×Jumper Wires
1×(Optional) Screw Terminal Adapter for Raspberry Pi

Or you can buy the following sensor kit:

1×DIYables Sensor Kit 30 types, 69 units
Disclosure: Some of the links provided in this section are Amazon affiliate links. We may receive a commission for any purchases made through these links at no additional cost to you. We appreciate your support.

Overview of DC Fan

Pinout

Fan Pinout
image source: diyables.io

A DC fan usually has two pins:

  • Negative (-) pin (black): needs to be connected to the negative wire of DC power supply
  • Positive (+) pin (red): needs to be connected to the positive wire of DC power supply

The voltage of the DC power supply should be equal to the voltage specified by the fan. In this tutorial, we will use 12VDC and 5VDC fans.

How to Control Fan

  • If DC fan is powered by 12V/5V power supply, it run with full speed.
  • If DC fan is powered by 12V/5V PWM signal, The fan's speed can be controlled.

This tutorial instructs you how to use Raspberry Pi to turn a 12V/5V fan on or off. We will cover controlling the fan's speed in another tutorial.

To control the fan on off, we need to use a relay between the Raspberry Pi and the fan. This relay can be used by Raspberry Pi to switch the fan on or off.

If you are unfamiliar with relays (pinout, operation, programming, etc.), please refer to the Raspberry Pi - Relay tutorial for more information.

Wiring Diagram

The wiring diagram between Raspberry Pi and Fan

This image is created using Fritzing. Click to enlarge image

Please note that if you use 5V fan, you need to use 5V power adapter.

Raspberry Pi Code

Detailed Instructions

  • Make sure you have Raspbian or any other Raspberry Pi compatible operating system installed on your Pi.
  • Make sure your Raspberry Pi is connected to the same local network as your PC.
  • Make sure your Raspberry Pi is connected to the internet if you need to install some libraries.
  • If this is the first time you use Raspberry Pi, See how to set up the Raspberry Pi
  • Connect your PC to the Raspberry Pi via SSH using the built-in SSH client on Linux and macOS or PuTTY on Windows. See to how connect your PC to Raspberry Pi via SSH.
  • Make sure you have the RPi.GPIO library installed. If not, install it using the following command:
sudo apt-get update sudo apt-get install python3-rpi.gpio
  • Create a Python script file fan.py and add the following code:
# This Raspberry Pi code was developed by newbiely.com # This Raspberry Pi code is made available for public use without any restriction # For comprehensive instructions and wiring diagrams, please visit: # https://newbiely.com/tutorials/raspberry-pi/raspberry-pi-fan import RPi.GPIO as GPIO import time # Set the GPIO mode (BCM or BOARD) GPIO.setmode(GPIO.BCM) # Define the GPIO pin controls the fan via the relay module RELAY_PIN = 12 # Set the relay pin as an output pin GPIO.setup(RELAY_PIN, GPIO.OUT) try: # Run the loop function indefinitely while True: # Turn the relay ON (HIGH) to turn on the fan GPIO.output(RELAY_PIN, GPIO.HIGH) time.sleep(5) # Wait for 5 seconds # Turn the relay OFF (LOW) to turn off the fan GPIO.output(RELAY_PIN, GPIO.LOW) time.sleep(5) # Wait for 5 seconds except KeyboardInterrupt: # If the user presses Ctrl+C, clean up the GPIO configuration GPIO.cleanup()
  • Save the file and run the Python script by executing the following command in the terminal:
python3 fan.py
  • Check out the fan's state.

The script runs in an infinite loop continuously until you press Ctrl + C in the terminal.

Code Explanation

Check out the line-by-line explanation contained in the comments of the source code!

Video Tutorial