// Define Pin Allocations const int irSensorPin = 2; // OUT pin connected to Digital Pin 2 const int ledPin = 13; // Onboard Arduino LED void setup() // Initialize Serial Communication Serial.begin(9600); // Configure Pin Modes pinMode(irSensorPin, INPUT); pinMode(ledPin, OUTPUT); void loop() // Read the sensor output (LOW means obstacle detected) int sensorState = digitalRead(irSensorPin); if (sensorState == LOW) digitalWrite(ledPin, HIGH); // Turn on the LED Serial.println("Obstacle Detected!"); else digitalWrite(ledPin, LOW); // Turn off the LED Serial.println("Path Clear."); delay(100); // Small delay to avoid flooding the serial monitor Use code with caution. Common Applications
The FC-51 is a low-cost, highly efficient infrared (IR) obstacle avoidance sensor widely used in robotics, automation, and smart home projects. This module utilizes a pair of infrared transmitting and receiving tubes to detect obstacles within a specific range. When an object enters the detection field, the infrared light reflects back to the receiver, triggering a digital output signal.
print('Checking for obstacles...') while True: if sensor.value() == 0: print('Obstacle detected!') switching() # Debounce: Wait until the sensor is clear again while True: time.sleep(0.5) if sensor.value() == 1: break time.sleep(0.1) Fc 51 Ir Sensor Datasheet
Detects entry through doorways or windows when an object breaks the invisible IR path.
A: You may have set the sensitivity too high. The sensor is detecting the floor or table surface. Turn the potentiometer counter-clockwise until the detection stops. // Define Pin Allocations const int irSensorPin =
If the reflected signal strength exceeds the threshold, the LM393 trips, turning on the onboard indicator LED and pulling the OUT pin LOW (0V) . When the path is clear, the OUT pin remains HIGH (VCC) via an internal pull-up resistor. Important Limitation: Surface Color Reflection
Acts as a photoelectric counter to track items passing down a conveyor belt. When an object enters the detection field, the
The blue potentiometer on the FC-51 adjusts the reference voltage for the LM393 comparator. This directly changes the detection distance.
Illuminates when an obstacle is detected within the set threshold.
When an object enters the sensor's field of view, the emitted IR light bounces off the object's surface.
The onboard infrared transmitting diode constantly emits invisible infrared light waves at a specific frequency.