LM393 Encoder Speed Sensor Module – Motor RPM Detection with Comparator

The LM393 Encoder is an infrared speed sensor module built around the LM393 comparator. It uses an IR emitter and phototransistor pair, interrupted by a rotating slotted disc, to generate accurate digital pulses. The on‑board comparator cleans up the raw signal, providing a crisp falling edge on each slot transition. Whether you need to measure motor RPM, count rotations for a robot odometer, or build a custom tachometer, this module delivers reliable performance with minimal wiring.

Key Specifications

What You Can Build With This

• Digital tachometer to monitor motor speed in real time
• Line‑following robot with closed‑loop speed feedback
• DIY anemometer rotation counter for wind speed measurement
• Robot odometer to track distance travelled

Compatibility

Works seamlessly with any microcontroller that has a digital input pin. Ideal for Arduino Uno, Nano, Mega, ESP8266, ESP32, and Raspberry Pi (use a voltage divider if connecting directly to Pi GPIO). The module outputs a 0–VCC pulse train, compatible with both 3.3V and 5V logic levels.

Wiring Notes

Connect VCC to 5V (or 3.3V), GND to ground, and OUT to any digital I/O pin. The on‑board comparator provides a clean signal without the need for external pull‑up resistors. For noisy environments, solder a 0.1µF ceramic capacitor between VCC and GND near the module pins.

Why Buy from Compoden

Every component is sourced from verified suppliers and tested for compatibility before listing. We've spent 10 years building projects for makers, schools, and institutions across India. Ships from Bengaluru in 3-5 days. If defective on arrival, replace within 7 days.