FC-51 IR Proximity Sensor - am I doing it wrong? - Arduino Forum
The FC-51 is a low-cost, highly efficient infrared (IR) obstacle avoidance sensor widely used in robotics, automation, and smart home projects. This module utilizes a pair of infrared transmitting and receiving tubes to detect obstacles within a specific range. When an object enters the detection field, the infrared light reflects back to the receiver, triggering a digital output signal. Fc 51 Ir Sensor Datasheet
Transmits infrared light at a specific frequency. FC-51 IR Proximity Sensor - am I doing it wrong
Because the FC-51 relies heavily on light reflection, its 2cm–30cm range varies under real-world conditions: Fc 51 Ir Sensor Datasheet
Scenario B: The Sensor does not detect objects at close range