LM393 Motor Speed Sensor Module for Arduino RPM Measurement
LM393 Motor Speed Measuring Sensor Module – Slot-Type Optocoupler with Comparator Output
The LM393 Motor Speed Measuring Sensor Module combines a slot-type infrared optocoupler with an LM393 precision comparator to deliver clean digital pulses for rotational speed measurement. By detecting interruptions from an encoder wheel or slotted disk, it provides accurate RPM data to any microcontroller. This module is a reliable choice for robotics, motor feedback systems, and DIY tachometer projects.
Key Specifications
| Specification | Value |
|---|---|
| Operating Voltage | 3.3V to 5V DC |
| Comparator IC | LM393 |
| Output Type | Digital (TTL compatible, active low) |
| Slot Width | 4 mm |
| Detection Method | Infrared slot-type optocoupler |
| Dimensions | 32 x 14 x 7 mm (approx.) |
What You Can Build With This
- Measure RPM of DC motors for precise speed control in robotics
- Build a digital tachometer for a drill press or lathe
- Implement speed feedback for a conveyor belt system
- Count revolutions for a custom odometer or usage tracker
Compatibility
This module works with any 3.3V or 5V microcontroller, including Arduino Uno, Nano, Mega, ESP32, ESP8266, Raspberry Pi Pico, and STM32 boards. The digital output connects directly to a GPIO pin. Pair it with an encoder code wheel (not included) with slotted holes to generate pulses proportional to speed.
Wiring Notes
Connect VCC to your microcontroller's 3.3V or 5V pin, GND to ground, and OUT to any digital input pin. The signal goes low when the slot is blocked by an opaque section of the encoder disk. No external pull-up resistor is required, but adding a 10kΩ pull-up can improve noise immunity in harsh environments.
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.
Is this compatible with Arduino?
Yes, connect VCC to 5V, GND to GND, and OUT to any digital pin. Use the pulseIn() function to measure pulse width or attach an interrupt to count pulses for RPM calculation.
Does it work with 3.3V systems like ESP32?
Absolutely. The LM393 comparator operates reliably at 3.3V, and the output logic level matches the supply voltage, making it safe for 3.3V GPIOs.
Can it measure low RPM accurately?
Yes, it can detect very slow rotations as long as the encoder disc passes through the slot. Measurement resolution depends on the number of slots in your encoder wheel.
📦 Free Setup Handoff Document Included
Every Compoden order includes a free setup handoff document — step-by-step instructions to get your component working within minutes. Download it via QR code on your package. The handoff document is also trained to help you troubleshoot the majority of problems.
What you can build with this
Shipping Information
- Prepaid Orders: ₹75 for orders up to ₹999, FREE shipping above ₹999
- COD Orders: ₹125 shipping + ₹50 COD fee = ₹175 total
- Delivery Timeline: Dispatch in 1-2 days, delivery in 2-7 days depending on location
Returns & Warranty
- 7-Day Return: Manufacturing defects only (approval required)
- Warranty: 7 days from delivery
- Non-Returnable: Batteries, consumables, cut wires, clearance items