Fc 51 Ir Sensor Datasheet !exclusive! 〈Linux〉

The FC-51 IR Obstacle Sensor is a cheap, widely available active infrared proximity sensor used heavily in robotics and automation. It operates as a simple binary switch, outputting a LOW or HIGH digital signal depending on whether it detects reflected light from an object.

Below are the in-depth technical specifications, pinout architecture, and critical operating limitations mapped directly from its standard industrial datasheet footprint. 📊 Core Technical Specifications

The operational limits of the module heavily dictate its deployment in embedded systems: Operating Voltage: 3.0V to 6.0V DC (Standard TTL levels) Current Consumption: ~23 mA at 3.3V | ~43 mA at 5.0V

Theoretical Detection Range: 2 cm to 30 cm (Subject to target reflectivity) Effective Detection Angle: ~35° field of view

Active Signal Output: LOW logic level when an obstacle is detected

Inactive Signal Output: HIGH logic level when the environment is clear

Core Components: Infrared LED emitter, Photodiode receiver, and an LM393 Voltage Comparator IC. 🔌 Pinout Configuration

The module features a standard 3-pin male header for seamless connectivity to microcontrollers like Arduino and ESP32: VCC: External voltage input (Connect to 3.3V or 5V source). GND: Ground reference (0V).

OUT: Digital output pin that connects straight to a microcontroller's GPIO. ⚡ Hardware Layout and Adjustments

The physical PCB board hosts several distinct elements designed to assist in calibration: distance with ir sensor fc-51 - Arduino Forum Fc 51 Ir Sensor Datasheet

When to consult the official datasheet

  • Precise electrical limits (absolute max ratings)
  • Exact LED wavelength and receiver spectral sensitivity
  • Precise current consumption
  • Pinout variations between vendors
  • Timing/response specs and recommended PCB layout/decoupling

Onboard Components

  • 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:
    • Power LED: Lights up when the module is powered.
    • Status LED: Lights up when an obstacle is detected (Output is LOW).

10. Limitations & Troubleshooting (From Datasheet Warnings)

Every engineer must know the limitations documented in the FC-51's fine print.

7. Typical Applications

  • Line-following robots (using two FC-51 modules)
  • Obstacle avoidance robots
  • Contactless proximity sensing (e.g., touchless faucets)
  • Edge detection for automated guided vehicles (AGVs)
  • Simple presence detection (e.g., trash can lid opener)

1. What is the FC-51 IR Sensor Module?

The FC-51 is a compact, low-cost infrared (IR) sensor module designed for digital obstacle detection. It operates by emitting infrared light from an IR LED and detecting the reflected light using a phototransistor. If an object is close enough, the reflected IR intensity is high, and the module outputs a digital signal (either HIGH or LOW) indicating the presence of the object.

Unlike analog IR sensors (such as the TCRT5000-based modules), the FC-51 includes an onboard comparator circuit (typically an LM393 chip) that converts the analog signal from the phototransistor into a clean digital output. This makes it extremely easy to interface with microcontrollers like Arduino, Raspberry Pi, ESP32, or STM32.

Key Feature: It has a built-in potentiometer to adjust the detection threshold (sensitivity range).

11. Frequently Asked Questions (FAQ)

Q1: What is the difference between FC-51 and LM393 IR sensor? A: "LM393" refers to the comparator IC. Many IR sensor modules (including FC-51) use the LM393. FC-51 is a specific board layout and component selection.

Q2: Can I use the FC-51 with 3.3V logic (e.g., ESP32, Raspberry Pi Pico)? A: Yes. The FC-51 operates from 3.3V to 5V. Connect VCC to 3.3V, and the OUT pin will output 3.3V logic HIGH, safe for 3.3V microcontrollers.

Q3: How to get an analog output from FC-51? A: If your module has an AOUT pin, read it using an ADC pin. If not, you can solder a wire directly to the phototransistor's collector or the comparator's non-inverting input.

Q4: Why does my sensor detect objects even when nothing is there? 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.

Q5: Can FC-51 detect transparent objects like glass? A: Not reliably. Glass reflects very little IR. It may detect the glass if the angle is steep, but generally, it is not suitable for transparent objects. The FC-51 IR Obstacle Sensor is a cheap,

Q6: What is the maximum refresh rate? A: Approximately 500 Hz (2 ms response time). You can read it reliably at intervals of 10 ms or more.

Conclusion

While the FC-51 lacks a formal, manufacturer-published datasheet (most are generic Chinese modules), the specifications and behavior outlined above are universally accepted by the maker community. It is not a precision instrument, but for $1–2 per module, it is an unbeatable workhorse for basic proximity sensing.

Remember: Always test your specific module’s range with your target object before finalizing your design.

Have you used the FC-51 in a creative project? Let us know in the comments below!

Final verdict — punchline

The FC-51 is a workhorse of the hobbyist world: seductive in its simplicity, practical for many classroom and maker tasks, but brittle when stretched beyond its implicit assumptions. Read its datasheet as a starting point — then test aggressively, account for variability, and treat the module as a fast prototype, not the final measurement instrument.

Key Features:

  1. Infrared Detection: The FC-51 IR sensor uses infrared radiation to detect objects or obstacles.
  2. Adjustable Sensitivity: The sensor has an adjustable potentiometer to adjust the sensitivity of detection.
  3. Digital Output: The sensor provides a digital output signal ( HIGH/LOW) indicating the presence or absence of an object.
  4. Operating Voltage: The sensor operates at a voltage range of 3.3V to 5V DC.
  5. Current Consumption: The sensor consumes a low current of around 20-30mA.
  6. Detection Range: The detection range of the FC-51 IR sensor is approximately 2-30cm (adjustable).

Technical Specifications:

  • Emitter: Infrared LED
  • Detector: Photodiode
  • Wavelength: 950nm
  • Operating Temperature: -20°C to 80°C
  • Storage Temperature: -20°C to 80°C

Applications:

  1. Robotics: Obstacle detection, line following, and tracking objects.
  2. Proximity sensing: Detecting the presence or absence of objects.
  3. Industrial automation: Detecting objects, monitoring production lines.
  4. Security systems: Intrusion detection, motion detection.

Datasheet:

If you're looking for the official datasheet of the FC-51 IR sensor, you can search for it on various online platforms, such as:

  • Google search: "FC-51 IR Sensor Datasheet"
  • Electronics component websites: Adafruit, SparkFun, or RobotShop
  • Chinese electronics marketplaces: AliExpress, BangGood

Keep in mind that the datasheet may vary depending on the manufacturer or the specific version of the sensor.

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.

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

Based on your request, here is the technical information and specification summary for the FC-51 Infrared Obstacle Avoidance Sensor Module.

This module is widely used in robotics (for line following or obstacle avoidance) and is based on the TCRT5000 IR sensor.