ESP32 - Control Fan

This tutorial instructs you how to use ESP32 to control a fan.

Hardware Used In This Tutorial

1×ESP-WROOM-32 Dev Module
1×USB Cable Type-C
1×12V DC Cooling Fan
1×(Alternative) 5V DC Cooling Fan
1×12V Power Adapter
1×Jumper Wires
1×(Optional) DC Power Jack
1×(Recommended) ESP32 Screw Terminal Adapter

Or you can buy the following sensor kits:

1×DIYables Sensor Kit (30 sensors/displays)
1×DIYables Sensor Kit (18 sensors/displays)
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Introduction to DC Fan


Fan Pinout
image source:

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 ESP32 to turn on/off a fan. Controlling the speed of a fan will be presented in another tutorial.

Because the fan uses the high voltage, we cannot connect it directly to ESP32, we need to connect fan to ESP32 indirectly via a relay. We have specific tutorials about relay (pinout, how it works, how to program ...), learn about relay in the ESP32 - Relay tutorial

Wiring Diagram

ESP32 Fan Wiring Diagram

This image is created using Fritzing. Click to enlarge image

If you're unfamiliar with how to supply power to the ESP32 and other components, you can find guidance in the following tutorial: How to Power ESP32.

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

ESP32 Code

The below code periodically turns the fan ON/OFF in every 10 seconds.

/* * This ESP32 code is created by * * This ESP32 code is released in the public domain * * For more detail (instruction and wiring diagram), visit */ #define RELAY_PIN 16 // ESP32 pin GPIO16, which connects to the fan the via the relay // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin A5 as an output. pinMode(RELAY_PIN, OUTPUT); } // the loop function runs over and over again forever void loop() { digitalWrite(RELAY_PIN, HIGH); // turn on fan 10 seconds delay(10000); digitalWrite(RELAY_PIN, LOW); // turn off fan 10 seconds delay(10000); }

Quick Instructions

  • If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
  • Do the wiring as above image.
  • Connect the ESP32 board to your PC via a micro USB cable
  • Open Arduino IDE on your PC.
  • Select the right ESP32 board (e.g. ESP32 Dev Module) and COM port.
  • Copy the above code and paste it to Arduino IDE.
  • Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
  • See the fan's state

Line-by-line Code Explanation

The above ESP32 code contains line-by-line explanation. Please read the comments in the code!

Video Tutorial

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