Fc 51 Ir Sensor Datasheet //top\\ May 2026

FC-51

The 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

beware of two different pinouts

The FC-51 module almost always comes with a standard 3-pin male header (0.1" spacing). However, found in the wild. Always verify with a multimeter before connecting. Fc 51 Ir Sensor Datasheet

• IR Transmitter (TX): An Infrared LED that emits invisible light.
• IR Receiver (RX): A photodiode or phototransistor sensitive to infrared light.
• LM393 Comparator: Compares the analog signal from the receiver with a reference voltage to provide a clean digital output.
• Potentiometer: A small blue screw terminal used to adjust the sensitivity (detection range).
• LEDs:
  1. Robotics: obstacle detection, line following, and wall detection.
  2. Automation: presence detection, distance measurement, and object detection.
  3. Proximity sensing: detecting the presence of objects within a certain range.

  (Optional: Connect an LED via a 220Ω resistor to Pin 13 for onboard LED indication.) FC-51 The is a low-cost infrared (IR) obstacle

  No object

  | Condition | Output Pin State | Indicator LED (Red) | What it means | | :--- | :--- | :--- | :--- | | | HIGH (1 / 3.3-5V) | OFF | Path is clear | | Object detected | LOW (0 / 0V) | ON | Object is within threshold | IR Transmitter (TX): An Infrared LED that emits