Adjustable from 2cm to 30cm via an onboard potentiometer.

The FC-51 IR sensor is a reliable and easy-to-use infrared sensor module suitable for various robotics and automation projects. Its simple digital output and adjustable sensitivity make it a popular choice among hobbyists and professionals. However, its limited range and potential interference from environmental factors should be considered when designing applications.

By referencing this , you now have the complete technical picture: pinouts, voltage limits, range adjustment, code examples, and troubleshooting. Whether you’re building a line-following robot, a contactless switch, or a factory counter, the FC-51 offers a straightforward “detect or not detect” solution that integrates with almost any microcontroller.

The phototransistor receives the reflected light, and the onboard comparator compares this signal against the threshold set by the potentiometer.

Example Arduino pseudo-code:

The FC-51 uses logic. This is crucial for programming.