Anonymous
Mar 22, 2026
Rating: 4/5
Solid component for workshops
We use these in our beginner electronics workshops. They are durable enough to handle student handling. The only minor issue is that the LED indicator is quite bright in dark rooms.
Description
Reviews
| Brand | - |
| Category | Robotics / STEM Teaching Tools / Sensors |
| Origin | - |
| Operating Voltage | 3.3V - 5V DC |
| Output Signal | Digital TTL Level |
| Sensor Type | Slot-Type Optocoupler |
| Slot Width | 5mm |
| Response Time | < 10 microseconds |
| Max Current | 20mA per channel |
| PCB Dimensions | 32mm x 14mm x 4mm |
| Mounting Hole Diameter | 3mm |
| Interface | 3-Pin Header (VCC, GND, OUT) |
| Application | Motor Speed Measurement & Pulse Counting |
Anonymous
Mar 22, 2026
Rating: 4/5
Solid component for workshops
We use these in our beginner electronics workshops. They are durable enough to handle student handling. The only minor issue is that the LED indicator is quite bright in dark rooms.
Anonymous
Mar 20, 2026
Rating: 5/5
Essential for control systems class
Bought two of these for a university project on feedback control loops. They are robust and provide the digital output needed for our PID controller implementation. No issues so far.
Anonymous
Mar 14, 2026
Rating: 5/5
Exactly as described
The module matches the description perfectly. It handles 5V logic levels easily and the PCB quality looks good with clear silkscreen markings. Will buy again for future prototypes.
Anonymous
Mar 09, 2026
Rating: 5/5
Perfect for Arduino RPM projects
This module works flawlessly with my Arduino Uno. The signal is clean and stable, making it very easy to calculate motor speed accurately. The slot size is perfect for standard encoder disks.
Anonymous
Mar 08, 2026
Rating: 4/5
Good value, needs careful alignment
Great sensor for the price. You need to be precise when aligning the interrupter disk within the slot, otherwise, you might get skipped pulses. Once aligned, it performs consistently.
Anonymous
Mar 08, 2026
Rating: 5/5
Reliable and fast shipping
Used this to build a tachometer for a small DC motor. The response time is incredibly fast, handling high RPMs without any lag. Highly recommended for hobbyist electronics.
Q: Can this sensor work directly with a Raspberry Pi GPIO?
A: Yes, since the output is 3.3V-5V TTL compatible, it can connect directly to Raspberry Pi GPIO pins. Just ensure you share a common ground between the module and the Pi.
Q: What is the maximum RPM this module can accurately measure?
A: Given the microsecond response time, it can theoretically handle hundreds of thousands of pulses per minute. Practical limits usually depend on your microcontroller's interrupt handling speed rather than the sensor itself.
Q: Is the output active high or active low?
A: When the slot is unobstructed, the output is typically High. When an object blocks the slot, the output goes Low. However, this can depend on specific internal circuitry, so we recommend testing with a multimeter upon arrival.
Q: Can I use this outdoors in direct sunlight?
A: Direct sunlight may interfere with the infrared beam and cause false readings. We recommend shielding the sensor from direct ambient light if used in outdoor applications.
Q: Does this come with an interrupter disk or do I need to make one?
A: The package includes only the sensor module. You will need to create or purchase a separate slotted disk or flag to attach to your motor shaft to interrupt the light beam.