Gesture Control smart fan

When both sensor are high fan will off, If one of them will high fan will rotate to that direction till it max angle.

IntermediateFull instructions provided3 hours99

Things used in this project

Hardware components

Arduino UNO

SG90 Micro-servo motor

DIYables RGB LED Module

DC Motor, Miniature

You can use motor depend on the size of your fan and weight

Story

Story Behind the Project

Traditional fans require physical switches or remotes, which can be inconvenient when the user is busy or far from the control. This project, Gesture-Based Smart Fan, solves that problem by allowing the fan to respond to simple hand gestures.

Using sensors and a microcontroller, the system detects hand movement to turn the fan ON or OFF and adjust its direction automatically. A servo motor enables smooth rotation, while intelligent timing logic ensures the fan turns OFF when no gesture is detected, saving energy.

This project demonstrates how embedded systems can create smart, contactless, and energy-efficient solutions for everyday use.

Code for project

#include <Arduino.h>
#include <Servo.h>
#include <LowPower.h>

#define LEFT_IR A1
#define RIGHT_IR A0
#define SERVO_PIN 9
#define FAN_PIN 11
#define RED_LED 5
#define BLUE_LED 7

Servo fanServo;

// === State ===
bool isLocked = false;
bool systemActive = false;
unsigned long lastDetectTime = 0;
unsigned long lockTimer = 0;
const unsigned long lockDelay = 5000;
int servoAngle = 90;

void setup() {
  pinMode(FAN_PIN, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  pinMode(BLUE_LED, OUTPUT);

  analogWrite(FAN_PIN, 0);
  digitalWrite(RED_LED, LOW);
  digitalWrite(BLUE_LED, LOW);

  fanServo.attach(SERVO_PIN);
  fanServo.write(servoAngle);

  Serial.begin(9600);
}

void loop() {
  int leftVal = analogRead(LEFT_IR);
  int rightVal = analogRead(RIGHT_IR);
  int avgVal = (leftVal + rightVal) / 2;//smothing

  // Thresholds
  const int detectThresh = 200;  // IR active when > 200
  const int moveThresh = 50;     // To detect hand direction
  const int steadyThresh = 40;   // For stability detection

  bool handNearLeft = leftVal > detectThresh;
  bool handNearRight = rightVal > detectThresh;
  bool handDetected = handNearLeft || handNearRight;

  // Sleep if nothing detected and not locked
  if (!handDetected && !isLocked) {
    systemActive = false;
    digitalWrite(RED_LED, LOW);
    digitalWrite(FAN_PIN, LOW);
    digitalWrite(BLUE_LED, LOW);
    LowPower.powerDown(SLEEP_1S, ADC_OFF, BOD_OFF);
    return;
  }

  // === Active Mode ===
  analogWrite(FAN_PIN,168);
  systemActive = true;

  if (!isLocked) {
    digitalWrite(RED_LED, HIGH);
    digitalWrite(BLUE_LED, LOW);

    // Servo movement
    int diff = leftVal - rightVal;
    if (abs(diff) > moveThresh) {
      servoAngle += (diff > 0) ? -2 : 2;
      servoAngle = constrain(servoAngle, 60, 120);
      fanServo.write(servoAngle);
    }

    // Check for lock condition
    if ((handNearLeft && !handNearRight && abs(leftVal - avgVal) < steadyThresh) ||
        (handNearRight && !handNearLeft && abs(rightVal - avgVal) < steadyThresh)) {
      if (millis() - lockTimer > lockDelay) {
        isLocked = true;
        lockTimer = millis();  // Reset for unlock timer
      }
    } else {
      lockTimer = millis();
    }
  } else {
    // === LOCKED STATE ===
    digitalWrite(RED_LED, HIGH);
    fanServo.write(servoAngle);  // Keep angle fixed

    // Show blue if hand moved away
    if (!handDetected) {
      digitalWrite(BLUE_LED, HIGH);
    }

    // Unlock if hand steady on both IRs
    if (handNearLeft && handNearRight && abs(leftVal - rightVal) < steadyThresh) {
      if (millis() - lockTimer > lockDelay) {
        isLocked = false;
        digitalWrite(BLUE_LED, LOW);
      }
    } else {
      lockTimer = millis();
    }
  }

  delay(100); // Small debounce
}