Laser module

By Admin, 15/09/2026 · 4 min read

Laser module guide for the 37-in-1 Arduino Sensors Kit.

37-in-1 kit, module 07

KY-008: Laser module

A red laser diode you switch on and off from a pin. Plug it in, upload the sketch, then change the thing it senses and watch the reading.

All 37 modules Nano and shield wiring Joy-IT page for this module

KY-008, Laser module

A red laser diode you switch on and off from a pin.

How it works

Laser module

What is going on

The brass cylinder is a 650 nm laser diode with its own lens and a resistor on the board. Set the signal pin high and it lights. It is a class 3R source: never look into it, never point it at anyone, and keep it below eye level on the bench. Pair it with the KY-018 photoresistor across a gap to make a beam-break detector.

Connections

Wiring to the Arduino Nano on its expansion shield

The pins below match the sketch further down this page; change one and change the other.

Power off first

Unplug the USB cable before you plug in, move or remove any module.

A lead plugged in live can touch the wrong pin for a moment, and 5 V on a signal pin is how a module dies. Unplug, wire, check the letters, then plug the cable back in.

Module pinGoes to

Module SignalS row of the column marked 13, digital bank

Module GNDG row, ground

Where it plugs in on the shield

The ringed column is the one this module uses. G on top for ground, V in the middle for 5 V, S at the bottom for the signal. A module with more than one signal wire uses one column per wire.

Read the letters on the shield

Both banks on this shield read G, V, S from the top. The letters are printed at the ends of the rows.

The module's minus or GND pin goes to G, its plus or VCC pin to V, and each signal to the S row of the numbered column.

A module in backwards puts 5 V on the signal pin. Some survive it, plenty do not.

Starter sketch

Code you can copy and upload

Every sketch on these pages is compiled for the Arduino Nano before it is published. The pin numbers at the top match the connection table above.

ky008.inoArduino C++

1const uint8_t LASER = 13;          // module S -> D13, module - -> G
2
3void setup() {
4  pinMode(LASER, OUTPUT);
5}
6
7void loop() {
8  digitalWrite(LASER, HIGH);
9  delay(500);
10  digitalWrite(LASER, LOW);
11  delay(500);
12}

Try first

Aim it at a sheet of paper on the bench and watch the dot blink.

The quickest way to see it respond.

1

Unplug the USB cable. Plug the module into the column shown above, minus to G, plus to V, signal to S.

2

Plug the USB cable back in. Copy the sketch, upload it, and open Tools > Serial Monitor at 9600 baud.

3

Do the thing the module senses and watch the reading, the L LED, or the sound respond.

Take care

Never point the laser at a face. Keep it aimed down at the bench.

Reference

More on this module

The Joy-IT page has the datasheet figures and examples for other boards; the repository has the original vendor files.

Joy-IT SensorKit: KY-008
KY-numbered kit repository: datasheets and original examples
Arduino Nano and I/O expansion shield wiring
Arduino Nano and DHT11 electronics workshop
All 37 modules

Survey and feedback

Help improve MakerAccess

Have an idea for what MakerAccess should stock, improve, or explain next? Share it in the survey. If you bought or used a product and want to comment on the item itself, use the product feedback form.

Do the survey Product feedback form