Fc 51 Ir Sensor Datasheet | PRO |

The FC-51 IR Sensor: Your Robot’s Secret "Spidey Sense" Ever wondered how those clever little vacuum robots avoid tumbling down the stairs or crashing into your favorite vase? Most of the time, they’re using a "Spidey sense" powered by infrared light. At the heart of many beginner DIY projects is the FC-51 IR Obstacle Avoidance Sensor

, a tiny but mighty module that brings your creations to life.

If you’ve been hunting for the elusive "official" datasheet, you’ve probably noticed it's a bit like a ghost—everyone knows what it does, but the original manufacturer's document is hard to find. Here is the definitive breakdown of everything you need to know to master this sensor. 🛠️ Technical Specifications at a Glance

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 FC-51 IR sensor is a versatile and low-cost infrared obstacle avoidance module widely used in robotics, security systems, and DIY electronics. This module, often referred to as the "Flying Fish" sensor, uses a pair of infrared emitting and receiving tubes to detect obstacles within a range of approximately 2 cm to 30 cm. FC-51 Technical Specifications

The FC-51 module is designed for ease of integration with microcontrollers like Arduino, Raspberry Pi, and ESP8266. Specification Operating Voltage 3.0V – 6.0V DC (Typical: 3.3V or 5V) Current Consumption ~23 mA at 3.3V; ~43 mA at 5.0V Detection Range 2 cm to 30 cm (Adjustable via potentiometer) Detection Angle Output Type Digital (HIGH/LOW logic) Active Output Level LOW when an obstacle is detected PCB Dimensions 3.1 cm (L) x 1.4 cm (W) Pinout Configuration

The FC-51 features a simple 3-pin male header for quick connections. VCC: Power input pin (connects to 3.3V - 5V). GND: Ground pin (0V). Fc 51 Ir Sensor Datasheet

OUT: Digital output pin that provides a signal based on detection status. Working Principle

The module operates based on infrared reflection. An onboard IR LED (the transparent transmitter) continuously emits infrared light. When an object enters the detection range, the light bounces off the object's surface and is captured by the IR receiver (the black photodiode). Go to product viewer dialog for this item. Googlehttps://www.google.com

IR Infrared Obstacle Avoidance Sensor Module | FC-51 for Arduino

The FC-51 is a low-cost infrared (IR) obstacle avoidance sensor module commonly used in robotics for short-range detection. It functions by emitting an IR signal from a transmitter LED; if an object is within range, the IR light reflects back and is detected by a receiver phototransistor, triggering a digital signal. Core Technical Specifications Specification Operating Voltage 3.0V – 6.0V DC Detection Range 2cm – 30cm (Adjustable via onboard potentiometer) Detection Angle Approximately 35° Current Consumption ~23 mA at 3.3V / ~43 mA at 5.0V Output Type

Digital signal (LOW when obstacle detected, HIGH when clear) Dimensions PCB: 3.1 cm x 1.4 cm; Overall: 4.5 cm x 1.4 cm x 0.7 cm Interface and Components Pinout: VCC: Power input (3.3V - 5V). GND: Ground connection. OUT: Digital output pin. Onboard Indicators: Power LED: Remains lit while the module is powered.

Obstacle LED: Lights up only when an object is detected within the set range. The FC-51 IR Sensor: Your Robot’s Secret "Spidey

Adjustment: A multi-turn potentiometer (blue trim pot) is used to increase (clockwise) or decrease (counter-clockwise) the sensitivity and detection distance. Operational Notes

4. Detection Principle

1. The IR LED continuously emits 38kHz–56kHz modulated infrared light (modulation helps reduce ambient light interference).
2. When an object comes close, IR light reflects off it and is picked up by the phototransistor.
3. The comparator circuit (often LM393) compares the reflected signal strength against a threshold voltage set by the onboard potentiometer.
4. If reflected IR exceeds the threshold → OUT = LOW (obstacle detected).
   Otherwise → OUT = HIGH (no obstacle).

6. Timing & Response

| Parameter | Value | |-----------|-------| | Response Time | ~2–10 ms | | Output Frequency | ~50–100 Hz (typical) | | Settling Time after power-up | <50 ms |

Suitable for obstacle detection at low to medium speeds (e.g., small robots, conveyor belts).

Part 6: Wiring and Interfacing with Microcontrollers

The FC-51’s 3.3V to 5V compatibility makes it an easy match for most platforms.

7. Common Issues

• Ambient Light Interference: Strong sunlight contains infrared light, which can flood the sensor and cause false readings. The module performs best indoors or in controlled lighting.
• Surface Color: Black surfaces absorb IR light (reducing detection range), while white surfaces reflect it well. This is why this sensor is standard for "Line Follower" robots (detecting black tape on a white floor).

4. Working Principle: How the FC-51 Detects Objects

The FC-51 module works on the principle of reflective infrared sensing.

1. Emission: The onboard IR LED continuously emits a 940nm infrared light (invisible to the human eye).
2. Reflection: When this IR light hits an object (within the detection range), it reflects back toward the sensor.
3. Reception: The phototransistor receives the reflected IR light. The more light it receives, the more current it conducts, lowering its output voltage.
4. Signal Processing: The voltage from the phototransistor is fed into the comparator (LM393) along with a reference voltage set by the potentiometer.
   • If the phototransistor voltage drops below the reference voltage (high reflection), the comparator output changes state (typically to LOW).
   • If it stays above the reference voltage (low reflection), the output remains HIGH.
5. Digital Output: The resulting digital signal (0 or VCC) is sent to the OUT pin.

Part 5: Adjusting the Detection Range

The FC-51 features a small, blue potentiometer (variable resistor) on the back of the PCB. Turning this potentiometer changes the comparator’s reference voltage, effectively adjusting the sensitivity. void loop() int sensorState = digitalRead(sensorPin)

How to calibrate:

1. Power the module and connect a multimeter to the OUT pin (or an LED with resistor).
2. Place a white object at the desired detection distance (e.g., 15 cm).
3. Slowly turn the potentiometer using a small screwdriver:
   • Clockwise (CW): Increases sensitivity. The sensor will detect objects farther away.
   • Counter-clockwise (CCW): Decreases sensitivity. The sensor will only detect close objects.
4. Stop turning when the output LED just turns ON (indicating detection). Remove the object; the LED should turn OFF.

Caution: Do not force the potentiometer past its stops. Adjust only ±270 degrees typically.

Simple Wiring Guide (Arduino Uno)

Connecting the FC-51 to a microcontroller is straightforward:

• FC-51 VCC → Arduino 5V
• FC-51 GND → Arduino GND
• FC-51 OUT → Arduino Digital Pin 2

Basic Arduino Code Example:

int sensorPin = 2;
int ledPin = 13;
void setup() 
pinMode(sensorPin, INPUT);
pinMode(ledPin, OUTPUT);
Serial.begin(9600);

void loop() 
int sensorState = digitalRead(sensorPin);
// Since output is Active LOW, "LOW" means object detected
if (sensorState == LOW) 
digitalWrite(ledPin, HIGH);
Serial.println("Obstacle detected!");
 else 
digitalWrite(ledPin, LOW);
Serial.println("Path clear");
delay(100);