Photo Interrupter Module

The Photo Interrupter Module is a slotted optical sensor that detects when something passes through its gap. An infrared LED on one side of the slot shines on a phototransistor on the other side; when an object blocks the beam, the output signal changes state. Because there is no physical contact, it is fast, reliable and does not wear out, which makes it ideal for counting, speed measurement and position sensing with Arduino and other microcontrollers.

Photo Interrupter Module Specifications

• Sensor type: slotted (U-shaped) photo interrupter
• Light source: infrared LED
• Receiver: phototransistor
• Output: digital signal that changes when the beam is blocked
• Detection: non-contact, for objects passing through the slot
• Mounting: small PCB with pin header

Photo Interrupter Module Applications

• Wheel encoders with a slotted disc for robot speed and distance
• RPM measurement of motors and fans
• Counting objects, coins or sheets of paper
• Home and limit position detection on sliders, 3D printers and CNC machines

What's in the Box

• 1 × photo interrupter module

Tip: Read the output with a digital pin and use an interrupt when counting fast pulses, such as from an encoder disc. The object must block infrared light; thin or clear plastic may not interrupt the beam fully.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.