Fc 51 Ir Sensor Datasheet !!better!! May 2026

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. 

Note: This is a synthesized feature datasheet. For official specifications, refer to the FC-51 vendor datasheet or test with your specific board version, as clones vary. Fc 51 Ir Sensor Datasheet

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. The FC-51 IR Obstacle Sensor is a cheap,

Alternate Pinout (Version B – Less Common)

| Pin Number | Name | Function | | :--- | :--- | :--- | | 1 | GND | Ground | | 2 | OUT | Digital output | | 3 | VCC | Power | For reliable operation

Practical implications and design guidance

• For reliable operation, always test sensors under representative lighting and with the actual materials in your application.
• Use modulation/demodulation (IR carrier + synchronous detection) or shielded housings if outdoor or variable-light use is required.
• Combine multiple sensors or complementary modalities (ultrasonic, time-of-flight) for robust obstacle detection or distance estimation.
• Prefer analog output versions if you need graded distance sensing and can implement signal processing in firmware.
• Add hysteresis or smoothing in firmware to prevent chatter around threshold points when using the digital output.