Ultrasonic Distance-Based LED Switch
Concept: This project uses an HC-SR04 ultrasonic sensor and an Arduino to activate an LED when an object is within 10 cm. This distance-based switch can serve as a touchless light control.
Materials
– Arduino Uno
– HC-SR04 Ultrasonic Sensor
– LED
– 220Ω Resistor
– Breadboard and Jumper Wires
Process:
1. Setup: The ultrasonic sensor’s Trig and Echo pins connect to Digital Pins 12 and 13 on the Arduino, while the LED is connected to Digital Pin 2 with a resistor.
2. Code: The Arduino reads the distance from the sensor. If within 10 cm, it lights the LED; otherwise, it turns off.
3. Testing: The LED successfully turns on when an object is close, providing feedback on proximity.
CODE:
const int echo = 13; // Echo pin of the ultrasonic sensor const int trig = 12; // Trigger pin of the ultrasonic sensor int LED = 2; // LED pin int duration = 0; // Variable to store pulse duration int distance = 0; // Variable to store calculated distance void setup() { pinMode(trig, OUTPUT); // Set trig pin as output pinMode(echo, INPUT); // Set echo pin as input pinMode(LED, OUTPUT); // Set LED pin as output Serial.begin(9600); // Initialize serial monitor for debugging } void loop() { // Send out a 10 microsecond pulse on the trig pin digitalWrite(trig, LOW); delayMicroseconds(2); digitalWrite(trig, HIGH); delayMicroseconds(10); digitalWrite(trig, LOW); // Read the echo pin and calculate distance duration = pulseIn(echo, HIGH); distance = (duration / 2) / 29.1; // Convert duration to distance in cm // Turn on the LED if the distance is less than 10 cm if (distance < 10 && distance > 0) { // Check distance within range digitalWrite(LED, HIGH); // Turn on LED } else { digitalWrite(LED, LOW); // Turn off LED } // Print distance to the serial monitor for debugging Serial.print("Distance: "); Serial.print(distance); Serial.println(" cm"); delay(500); // Delay for stability }
VIDEO DEMONSTRATION
Reflection: This project demonstrates basic sensor integration and is adaptable for touchless applications in home automation.