The Optical Speed Measuring Sensor is a compact infrared photoelectric sensor module designed for detecting rotational speed, counting pulses, and monitoring movement in robotics and electronic projects.
The module uses an infrared emitter and receiver positioned across a 6mm detection slot. When an object passes through the slot and interrupts the infrared beam, the sensor generates a digital output signal that can be read by a microcontroller.
Equipped with a Schmitt trigger circuit for stable signal detection and an onboard output indicator, this module is suitable for motor speed measurement, encoder wheels, pulse counting, and automation applications.
It operates from 3.3V to 5V DC, making it suitable for Arduino, ESP32, and other compatible microcontroller platforms.
Key Features
- Infrared optical detection for speed and movement measurement.
- 6mm detection slot for encoder discs and moving objects.
- Digital output for easy microcontroller interfacing.
- Schmitt trigger circuit for improved signal stability.
- Onboard LED indicator for output status.
- Designed to reduce interference from external light.
- Compatible with 3.3V and 5V microcontroller systems.
- Compact and lightweight design.
- Three mounting holes for installation.
- Suitable for rotational speed measurement and pulse counting.
Technical Specifications
| Parameter |
Specification |
| Product Type |
Infrared Optical Speed Sensor |
| Detection Method |
Infrared Beam Interruption |
| Operating Voltage |
3.3V–5V DC |
| Output Type |
Digital (DOUT) |
| Detection Slot Width |
6mm |
| Signal Conditioning |
Schmitt Trigger Circuit |
| Output Indicator |
Onboard LED |
| Module Dimensions |
26.8 × 15 × 18.7mm |
| Weight |
Approximately 4g |
| Mounting |
3 Mounting Holes |
| Interface |
3-Pin (VCC, GND, DOUT) |
| Compatible Platforms |
Arduino, ESP32, Raspberry Pi (with suitable logic levels) |
Pin Configuration
| Pin |
Description |
Connection |
| VCC |
Power Supply |
3.3V or 5V |
| GND |
Ground |
Microcontroller GND |
| DOUT |
Digital Output |
Digital Input / GPIO |
Connection Example – Arduino UNO
| Sensor Pin |
Arduino UNO |
| VCC |
5V |
| GND |
GND |
| DOUT |
D2 |
The Arduino reads the digital pulses generated whenever an object interrupts the infrared beam.
Motor Speed Calculation:
RPM = (Pulse Count × 60) / (Pulses per Revolution × Measurement Time in Seconds)
Example:
If the sensor detects 20 pulses in one second using an encoder disc with 20 slots:
RPM = (20 × 60) / (20 × 1)
Motor Speed = 60 RPM
Applications
- DC motor speed measurement
- Robot wheel speed monitoring
- Encoder disc detection
- Rotational speed measurement
- Pulse counting
- Object detection
- Conveyor belt monitoring
- DIY tachometers
- Robotics and automation projects
- Educational electronics experiments
Important Notes
- The sensor detects interruptions in an infrared beam and does not measure RPM directly. Speed is calculated by a microcontroller.
- An encoder disc or suitable rotating object is required for rotational speed measurement.
- The sensor output changes state when the infrared beam is interrupted.
- The output logic level and polarity should be checked before integration.
- When connecting to ESP32 or Raspberry Pi, ensure the digital output does not exceed 3.3V.
- Strong ambient infrared light may affect detection reliability.
- The module does not measure rotational direction by itself.
Package Includes
