Adafruit T-Slot Photo Interrupter

This T-Slot Photo Interrupter is a robust plastic sensor equipped with an IR LED and an IR photo-transistor, carefully positioned across a U-shaped gap.

You control the IR LED to emit light across the gap to the detector. When an object enters the slot and blocks the light, the sensor switches off. When the object moves away, the sensor receives the IR light and activates.

Perfect for applications like counting rotations with slotted encoder wheels, this sensor can determine rotational speed and display it on an OLED.

Notably, a red LED signals when the sensor is triggered, and built-in protection circuitry ensures reliable performance.

Key specifications include a power requirement of at least 5V for the Vin line, but the open-collector output transistor allows for connection to 3V logic with a pullup resistor.

The sensor is designed without an attached cable but has clearly labeled pads for easy connections: (+) for VCC (5-24V), L for LED configuration, OUT for transistor output, and (-) for Ground.