What is an IR Sensor?

An IR sensor, typically used for object detection and obstacle avoidance, works by emitting infrared light and measuring the reflection of that light. It is commonly used in robotics, home automation, and security systems.

Working Principle of IR Sensor

The IR sensor operates based on the reflection of infrared light:

• The IR LED emits infrared light.
• The infrared light hits an object and reflects back.
• The sensor detects the reflected light and produces a signal indicating the presence or absence of an object.

Formula: Object detected = (Reflected light intensity > Threshold)

Components Required

• ESP32 board
• IR Sensor (e.g., TCS3200, KY-032)
• Jumper wires
• Breadboard (optional)

Pin Configuration of IR Sensor

• VCC: Power supply (typically +3.3V or +5V depending on sensor)
• GND: Ground
• OUT: Output pin (Digital signal indicating detection)

Ensure the IR sensor operates at 3.3V logic level for ESP32 compatibility.

Wiring IR Sensor to ESP32

• VCC -> 3.3V (or 5V if supported)
• GND -> GND
• OUT -> GPIO 14

Arduino Code for ESP32 + IR Sensor

1#define IR_PIN 14
2
3int sensorValue;
4
5void setup() {
6  Serial.begin(115200);
7  pinMode(IR_PIN, INPUT);
8}
9
10void loop() {
11  sensorValue = digitalRead(IR_PIN);
12
13  if (sensorValue == HIGH) {
14    Serial.println("Object Detected");
15  } else {
16    Serial.println("No Object");
17  }
18
19  delay(500);
20}

Code Explanation (Line-by-Line)

• #define IR_PIN 14: Assigns GPIO 14 as the input pin connected to the IR sensor's output.
• Serial.begin(115200);: Starts serial communication for debugging/output.
• pinMode(IR_PIN, INPUT);: Sets the mode of IR_PIN as input to read the sensor's output.
• sensorValue = digitalRead(IR_PIN);: Reads the digital signal from the IR sensor. If the sensor detects an object, it returns HIGH, else LOW.
• if (sensorValue == HIGH) {...}: Checks if the sensor output is HIGH (object detected). If true, it prints 'Object Detected'.
• Serial.println("No Object");: If no object is detected (LOW), it prints 'No Object'.

Applications

• Obstacle Avoidance in Robots
• Object Detection for Automation Systems
• Line Following Robots
• Security Systems
• Home Automation (e.g., Automatic Doors)