FC-51 Sensor Arduino Uno / Microcontroller +--------------+ +--------------+ | VCC |------------------->| 5V | | GND |------------------->| GND | | OUT |------------------->| Digital Pin 2| +--------------+ +--------------+ Pull-Up Resistor Notice:
Connecting the FC-51 to an Arduino is straightforward due to its direct digital output. Wiring Diagram Arduino Pin GND OUT Digital Pin 2 Sample Arduino Sketch
Connect the FC-51 sensor to an Arduino board using the following pin map: →right arrow Arduino 5V or 3.3V GND →right arrow Arduino GND OUT →right arrow Arduino Digital Pin 2 Sample Arduino Code
Mounted on the front or sides of autonomous rovers to prevent collisions.
Illuminates only when an object reflects enough IR light to trigger the output threshold. If this LED is on, the OUT pin is driving a LOW signal. Working Principle and Physics Fc 51 Ir Sensor Datasheet
Think of the FC-51 as a digital gatekeeper. It doesn't tell you an object is; it just tells you something is there. distance with ir sensor fc-51 - Arduino Forum
: The transmitter continuously sends out IR waves at a specific frequency.
2cm to 30cm (Adjustable via potentiometer) Detection Angle: 35°
/* FC-51 IR Obstacle Avoidance Sensor Testing Code The OUT pin goes LOW when an obstacle is detected. */ const int SENSOR_PIN = 2; // FC-51 OUT pin connected to Digital Pin 2 const int LED_PIN = 13; // Onboard Arduino LED void setup() pinMode(SENSOR_PIN, INPUT); // Configure sensor pin as input pinMode(LED_PIN, OUTPUT); // Configure LED pin as output Serial.begin(9600); // Initialize serial monitor Serial.println("FC-51 Sensor Initialized."); void loop() int sensorState = digitalRead(SENSOR_PIN); // Read digital state if (sensorState == LOW) // Obstacle detected digitalWrite(LED_PIN, HIGH); Serial.println("Status: OBSTACLE DETECTED"); else // Path is clear digitalWrite(LED_PIN, LOW); Serial.println("Status: Clear"); delay(100); // Small delay to avoid flooding serial monitor Use code with caution. 7. Common Applications If this LED is on, the OUT pin is driving a LOW signal
Emits an infrared beam at a specific frequency.
The reflected IR light is captured by the onboard IR receiver (a black photodiode).
If you find the detection range is too short (e.g., under 10cm), try . Pushing them slightly closer or ensuring they are perfectly parallel can sometimes improve the range up to 30cm.
The FC-51 is a small, low-cost infrared (IR) proximity and line-detection module built around a matched IR emitter and receiver pair and simple signal-conditioning electronics. Its appeal is immediate: accessible to hobbyists, useful in robotics and embedded projects, and omnipresent in low-budget sensing tasks. That ubiquity is the module’s strength and its trap — inexpensive, well-known, and often used without a full appreciation of its limits. distance with ir sensor fc-51 - Arduino Forum
The comparator pulls the OUT pin and illuminates the obstacle indicator LED.
Because the sensor relies on light reflection, surface color and texture drastically impact performance:
Glows green or red when the module is correctly powered.