Fc 51 Ir Sensor Datasheet May 2026

FC-51

The is a popular infrared (IR) obstacle avoidance sensor module commonly used in Arduino and robotics projects . It uses an IR transmitter (LED) and receiver (phototransistor) to detect objects within a specific range by measuring the reflection of infrared light. Technical Specifications

By understanding the pinout, electrical characteristics, and the crucial role of the LM393 comparator, you can integrate the FC-51 into your projects with confidence. Whether you are building a robot that navigates a maze or a simple hand sanitizer dispenser, the FC-51 offers a perfect balance of performance and simplicity. Fc 51 Ir Sensor Datasheet

Practical implications and design guidance

3. Pinout (4-pin interface)

Part 1: What is the FC-51 IR Sensor?

Why LOW when active?

| Problem | Likely Cause | Solution | | :--- | :--- | :--- | | Output always HIGH | Sensitivity too low / Object too far | Turn potentiometer clockwise. | | Output always LOW | Sensitivity too high / Always detecting floor | Turn potentiometer counter-clockwise. | | Erratic output | Loose wiring / Power supply noise | Check connections; add a 100µF capacitor across VCC/GND. | | Detects only white, not black | Normal behavior | Increase sensitivity or move sensor closer. | | No output change at all | Wrong pin mapping or dead sensor | Test with multimeter: VCC = 5V, OUT should toggle when covering sensor with hand. | FC-51 The is a popular infrared (IR) obstacle

void loop() int sensorValue = digitalRead(sensorPin); if (sensorValue == LOW) // Obstacle detected digitalWrite(ledPin, HIGH); Serial.println("Obstacle!"); else digitalWrite(ledPin, LOW); Whether you are building a robot that navigates