Attributes

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 Frequency	20 kHz
LED Indicator	Yes (Power and Signal)
Mounting Hole Diameter	3mm
PCB Dimensions	32mm x 14mm
Interface Pins	VCC, GND, OUT

6 reviews

Anonymous

Mar 23, 2026

Rating: 5/5

Perfect for RPM projects

This module works flawlessly with my Arduino tachometer project. The signal is clean and the response time is very fast. Highly recommended for motor testing.

Anonymous

Mar 17, 2026

Rating: 5/5

Exactly as described

Arrived quickly and worked immediately upon connection. The slot width is perfect for standard encoder disks. No noise issues observed.

Anonymous

Mar 07, 2026

Rating: 4/5

Great for learning

Used this for a university lab experiment on motor control. It provided consistent data. Would be nice if it came with a sample code sheet, but online resources are plentiful.

Anonymous

Mar 07, 2026

Rating: 4/5

Good value, easy to use

Very straightforward to wire up. The LEDs make debugging easy. I deducted one star because the mounting holes are a bit tight for standard screws, but overall a great sensor.

Anonymous

Mar 06, 2026

Rating: 5/5

Reliable speed counting

I used this to count rotations on a small DC motor. It handles high speeds without missing pulses. The build quality feels solid for the price.

Anonymous

Mar 02, 2026

Rating: 5/5

Bulk buy success

Purchased ten of these for our workshop. All units tested perfectly. The optocoupler isolation is a nice feature for protecting microcontrollers.

5 FAQ

Q: What is the maximum width of the object that can pass through the slot?

A: The slot width is approximately 5mm. Any opaque object thinner than 5mm can interrupt the beam to trigger a signal.

Q: Can I use this to measure water flow if I attach a spinner?

A: Yes, as long as the spinner has vanes that fit within the 5mm slot and rotate at a frequency under 20kHz, it will work effectively for flow measurement.

Q: Does this output analog or digital signals?

A: This module outputs a digital TTL level signal. It switches between HIGH and LOW states when the slot is blocked or unblocked.

Q: Can this module work directly with a 3.3V microcontroller like ESP32?

A: Yes, the module supports an operating voltage range of 3.3V to 5V, making it fully compatible with 3.3V logic systems like the ESP32.

Q: Is there a pull-up resistor included on the board?

A: Yes, the PCB includes necessary circuitry including pull-up resistors, so you can connect the OUT pin directly to your microcontroller input.

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