Arduino Project

Arduino Fan Speed Control Project with DC Motor V3

Course Introduction

This Arduino project controls a DC motor using a TA6586 motor driver and three push buttons and I2C LCD. The blue button runs the motor at full speed in reverse, the yellow button runs it at half speed in reverse, and the red button stops the motor. The system uses PWM control to adjust speed and responds immediately to button input.

Note

If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.

1.1 Install Arduino IDE(Important)
1.2 Introduction of Arduino IDE

Required Components

In this project, we need the following components:

SN	COMPONENT INTRODUCTION	QUANTITY	PURCHASE LINK
1	Arduino UNO R4 Minima/Arduino UNO R4 WIFI	1	BUY
2	USB Type-C cable	1	×
3	Breadboard	1	BUY
4	Wires	Several	BUY
5	DC Motor	1	BUY
6	TA6586 - Motor Driver Chip	1	×
7	Button	3	BUY
8	Button	3	BUY
9	I2C LCD 1602	1	BUY

Wiring

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Common Connections:

TA6586 - Motor Driver Chip
BI: Connect to 6 on the Arduino.
FI: Connect to 5 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.

DC Motor
GND: Connect to TA6586 B0.
VCC: Connect to TA6586 F0.

Button1
Connect to breadboard’s negative power bus.
Connect to 9 on the Arduino.

Button2
Connect to breadboard’s negative power bus.
Connect to 10 on the Arduino.

Button3
Connect to breadboard’s negative power bus.
Connect to 11 on the Arduino.

I2C LCD 1602
SDA: Connect to A4 on the Arduino.
SCL: Connect to A5 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.

Writing the Code

Note
You can copy this code into Arduino IDE.
To install the library, use the Arduino Library Manager and search for LiquidCrystal I2C and install it.
Don’t forget to select the board(Arduino UNO R4 WIFI) and the correct port before clicking the Upload button.

#include <Servo.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// ===== Pin definitions =====
const int fiPin = 5;      // Motor control pin
const int biPin = 6;      // Motor control pin
const int blueBtn = 10;   // Blue button: change speed level
const int redBtn = 11;    // Red button: turn off the fan
const int greenBtn = 12;  // Green button: toggle servo swing
const int servoPin = 3;   // Servo control pin

// ===== Create objects =====
Servo servo;
LiquidCrystal_I2C lcd(0x27, 16, 2); // LCD address 0x27, 16x2 screen

// ===== Variables =====
int speedLevel = 0;          // 0=OFF, 1=Low, 2=Mid, 3=High
bool swingActive = false;    // Whether the servo swing is ON or OFF
int angle = 90;              // Servo starting angle (center position)
int direction = 1;           // 1=right, -1=left (for swing movement)
bool lastBlue = HIGH;        // Store last blue button state
bool lastRed = HIGH;         // Store last red button state
bool lastGreen = HIGH;       // Store last green button state

// ===== Servo movement range =====
const int leftLimit = 45;
const int rightLimit = 135;

// ===== Servo timing (non-blocking) =====
unsigned long lastServoMove = 0;
const unsigned long servoInterval = 30;  // Move every 30ms

void setup() {
  // ===== Pin setup =====
  pinMode(fiPin, OUTPUT);
  pinMode(biPin, OUTPUT);
  pinMode(blueBtn, INPUT_PULLUP);
  pinMode(redBtn, INPUT_PULLUP);
  pinMode(greenBtn, INPUT_PULLUP);

  // ===== Servo setup =====
  servo.attach(servoPin);
  servo.write(angle); // Move servo to center

  // ===== LCD setup =====
  lcd.init();          // Initialize LCD
  lcd.backlight();     // Turn on backlight
  lcd.clear();         // Clear screen
  updateLCD();         // Show initial message
}

void loop() {
  // ===== Read button states =====
  bool blueState = digitalRead(blueBtn);
  bool redState = digitalRead(redBtn);
  bool greenState = digitalRead(greenBtn);

  // ===== Blue button: switch fan speed =====
  // Each press changes speed: 1 → 2 → 3 → 1
  if (lastBlue == HIGH && blueState == LOW) {
    speedLevel++;
    if (speedLevel > 3) speedLevel = 1;
    updateLCD();
  }

  // ===== Red button: turn off the fan =====
  // Stop motor and servo
  if (lastRed == HIGH && redState == LOW) {
    speedLevel = 0;
    swingActive = false;
    updateLCD();
  }

  // ===== Green button: toggle servo swing =====
  // Only works when the fan is ON
  if (lastGreen == HIGH && greenState == LOW) {
    if (speedLevel > 0) {
      swingActive = !swingActive;
      updateLCD();
    }
  }

  // Save last button states
  lastBlue = blueState;
  lastRed = redState;
  lastGreen = greenState;

  // ===== Control fan speed =====
  int fanSpeed = 0;
  if (speedLevel == 1) fanSpeed = 100;
  else if (speedLevel == 2) fanSpeed = 180;
  else if (speedLevel == 3) fanSpeed = 255;
  else fanSpeed = 0;

  // Apply speed to the motor (PWM control)
  if (fanSpeed > 0) {
    analogWrite(biPin, fanSpeed);
    analogWrite(fiPin, 0);
  } else {
    analogWrite(biPin, 0);
    analogWrite(fiPin, 0);
  }

  // ===== Servo swing motion =====
  // Move servo back and forth when swing is active
  if (swingActive && speedLevel > 0) {
    unsigned long currentMillis = millis();
    if (currentMillis - lastServoMove >= servoInterval) {
      lastServoMove = currentMillis;

      angle += direction;
      if (angle >= rightLimit) direction = -1;
      if (angle <= leftLimit) direction = 1;

      servo.write(angle);
    }
  }
}

// ===== LCD display update function =====
// Refreshes the LCD when fan speed or swing state changes
void updateLCD() {
  lcd.clear();

  // Line 1: Fan speed and state
  lcd.setCursor(0, 0);
  lcd.print("Fan Speed: ");
  if (speedLevel == 0) lcd.print("OFF");
  else lcd.print(speedLevel);

  // Line 2: Swing status
  lcd.setCursor(0, 1);
  lcd.print("Swing: ");
  if (speedLevel == 0) lcd.print("--");
  else lcd.print(swingActive ? "ON " : "OFF");
}

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Arduino Project

Arduino Fan Speed Control Project with DC Motor V3

Course Introduction

Required Components

Wiring

Common Connections:

Writing the Code

Arduino Project

Arduino Fan Speed Control Project with DC Motor V3

Course Introduction

Required Components

Wiring

Common Connections:

Writing the Code

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