Introduction

An IR Obstacle Detector is an electronic system used to detect the presence of objects using infrared (IR) radiation. It is widely used in robotics, automation, and safety systems to avoid collisions and detect nearby obstacles.

This project demonstrates how infrared sensors can be used to detect objects without physical contact.

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Objective of the Project

The objectives of this project are:

• To detect obstacles using infrared light.
• To understand IR transmission and reflection.
• To generate an alert when an object is detected.
• To learn basic sensor interfacing techniques.

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Working Principle

The IR obstacle detector works on the principle of infrared reflection.

Basic Operation

1. The IR transmitter emits infrared light continuously.
2. When an object comes in front of the sensor, IR light reflects back.
3. The IR receiver detects the reflected light.
4. The output changes and activates an LED or buzzer.

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Components Required

Basic IR Obstacle Detector

• IR LED (Transmitter)
• IR Receiver (Photodiode / TSOP)
• LM358 Comparator IC
• Resistors (220Ω, 10kΩ)
• Potentiometer (10kΩ)
• LED / Buzzer
• Power Supply (5V)
• Breadboard & Wires

Arduino-Based IR Obstacle Detector

• Arduino Uno
• IR Sensor Module
• LED / Buzzer
• Jumper wires

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Circuit Diagram

Basic Circuit

IR LED ---> Object ---> IR Receiver
                |
             LM358
                |
              LED/Buzzer

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Arduino-Based Circuit

IR Sensor OUT ---- D8 (Arduino)
VCC ------------- 5V
GND ------------- GND
LED/Buzzer ------ D9

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Arduino Code (Optional)

int sensorPin = 8;
int buzzerPin = 9;

void setup() {
  pinMode(sensorPin, INPUT);
  pinMode(buzzerPin, OUTPUT);
}

void loop() {
  if (digitalRead(sensorPin) == HIGH) {
    digitalWrite(buzzerPin, HIGH);
  } else {
    digitalWrite(buzzerPin, LOW);
  }
}

Code Explanation

• Arduino reads the IR sensor output.
• When an obstacle is detected, the buzzer or LED is activated.
• When no obstacle is present, the output remains OFF.

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Advantages

• Non-contact detection
• Fast response time
• Low power consumption
• Simple and reliable

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Applications

• Obstacle-avoiding robots
• Automatic doors
• Parking assistance systems
• Industrial automation
• Security systems

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Limitations

• Affected by sunlight
• Limited detection range
• Depends on object surface reflectivity

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Conclusion

The IR Obstacle Detector is a basic yet powerful electronics project that introduces sensor-based detection. It plays a crucial role in robotics and automation systems and can be further enhanced using microcontrollers, IoT platforms, or AI-based decision-making.

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