Sensor Datasheet — Fc 51 Ir

  • Calibration: Rotate the onboard potentiometer to set the threshold distance. Clockwise usually increases resistance (decreases range), while counter-clockwise decreases resistance (increases range), though this depends on the specific board revision.

    • Even a simple sensor like the FC-51 can exhibit issues. Here’s a troubleshooting guide:

    | Symptom | Possible Cause | Solution | | :--- | :--- | :--- | | Output LED always ON | Potentiometer too sensitive; object too close; power supply noise | Turn potentiometer CCW; move objects; add capacitor | | Output LED always OFF | No power; broken IR LED; range too low | Check Vcc/GND; turn potentiometer CW; test with white paper | | Erratic detection | Ambient IR noise (sunlight, CFLs); loose wires | Shield sensor; use shorter wires; add 10ms debounce in code | | Very short range (under 5 cm) | Potentiometer misadjusted; black target | Recalibrate; use reflective tape on target | | Module gets hot | Reverse polarity | Immediately disconnect; check pinout version | Fc 51 Ir Sensor Datasheet

    The module typically comes with a 3-pin male header interface: Calibration : Rotate the onboard potentiometer to set

    | Pin Number | Name | Function | | :--- | :--- | :--- | | 1 | OUT | Digital output signal (HIGH = no object, LOW = object detected) | | 2 | VCC | Power supply input (3.3V or 5V) | | 3 | GND | Ground (0V) | Even a simple sensor like the FC-51 can exhibit issues

    Simply change the condition to:

    if (sensorValue == HIGH) { // Object detected

    | Feature | FC-51 | TCRT5000 (Module) | Sharp GP2Y0A21 | | :--- | :--- | :--- | :--- | | Output Type | Digital (fixed threshold) | Analog (variable) | Analog (variable) | | Detection Range | 2-30 cm | 1-15 cm | 10-80 cm | | Distance Measurement | No (only threshold) | Possible with ADC | Yes (linearized) | | Ambient Light Reject | Moderate | Low | High (modulated) | | Cost | Very Low ($1-2) | Low ($2-3) | High ($10-15) | | Best For | Obstacle detection, line following | Short-range proximity | Distance sensing applications |