HiLetgo 5V 650nm 5mW Red Dot Diode Laser Review and Code

Today I review the HiLetgo 5V 650nm 5mW Red Dot Diode Laser for Arduino and provide example code.

Overview of the HiLetgo 5V 650nm 5mW Red Dot Diode Laser

The HiLetgo 5V 650nm red dot diode laser is a cheap and incredibly powerful laser diode.

This laser diode produces light in the 650 nm range and produces a red dot of around 3.5 mm in diameter.

This laser diode requires 5 volts to produce a laser beam rated at 5mW which, as noted above, is quite powerful. When working with these it is recommended to use eye protection to ensure no permanent damage.

This laser diode has two pins, VCC and GND, which allows it to be easily controlled from the Arduino. This can be done either by connecting the 5V and GND lines directly or using a digital pin to control turning on the laser.

Wiring it up to an Arduino

The laser diode has two wires, red and blue. The blue wire needs to be wired to the Arduino’s ground pin. The red wire needs to be connected to a 5 volt line.

This can either be done by connecting it to the Arduino’s 5 volt pin or using a digital pin. In the below code I have connected it to the Arduino’s digital pin 5.

Programming the Diode Laser to flash

To program the diode laser to flash I am going to use pin 5 on the Arduino.

#define LASER_PIN 5

void setup() {

void loop() {
  digitalWrite(LASER_PIN, HIGH);
  digitalWrite(LASER_PIN, LOW);

Here I define LASER_PIN as 5 and use it in the code to define the pin used to connect the diode to. In the setup I then set out that pin as an output.

Inside the loop the pin is written to as HIGH, then LOW, changing every 500 ms. This creates the flashing diode. Since HIGH for the Arduino digital pins is 5 volts I don’t need any resistors or voltage dividers.

Review for the HiLetgo 5V 650nm 5mW Red Dot Diode Laser

This small laser diode is very powerful for the cost. Since its also relatively low power running on 5 volts it means it can easily be implemented in small micro-controller projects.

For any small project that needs a laser diode the cheap cost and high power makes this ideal.

Would buy again!

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