Laser Light Security System with Raspberry Pi Pico & LDR

Overview

In this project, we have designed Laser Light Security System Using Raspberry Pi Pico Board & LDR module. The project idea revolves around creating a security system. Whenever any object will obstruct the LASER ray the RGB LED will start blinking.

When you start the program, RGB LED initially displays green. We use the red laser emitter to aim at the LDR Light sensor and start timing. When it locks on the target (Light sensor), the RGB flashes red and blue, and stops timing.

This project can be implemented anywhere, not only in buildings or premises but many precious things like jewelry, diamonds, precious antique items in the museum, etc many other things are also secured using such an invisible LASER beam. Many people secure their homes, office, shops, warehouses, etc with the LASER beam security system. You can also make Anti-Theft Alarm project using Raspberry Pi Pico.

Components Required

In this guide, I used Elecrow Raspberry Pi Pico Starter Kit to test different Modules. You can buy the kit and perform some other operations as well. From this kit, you can use the following components.

1. Raspberry Pi Pico Board -1
2. Laser Light Module – 1
3. LDR Sensor Module – 1
4. RGB LED Module – 1
5. Breadboard -1
6. Jumper Wires – 10
7. Micro-USB Cable

Laser Light Module

The laser Transmitter module emits a dot-shaped, red laser beam. The Laser transmitter module consists of a 650nm red laser diode head and a resistor. Handle with caution, do not look directly into the laser head.

The specification of Laser Transmitter Module KY-008 is as follows:

• Operating Voltage – 5V
• Output Power – 5mW
• Wavelength – 650nm
• Operating Current – less than 40mA
• Working Temperature – -10°C ~ 40°C [14°F to 104°F]
• Dimensions – 18.5mm x 15mm

Circuit Diagram & Hardware Setup

Here is a simple connection diagram for Laser Light Security System with Raspberry Pi Pico & LDR.

Connect the R, G & B Pin of the RGB LED to Raspberry Pi Pico GP2, GP3 & GP4 Pin respectively. Connect the GND Pin of RGB LED to Pico GND Pin.

Connect the LDR Sensor Module to GP0 of Raspberry Pi Pico. Also, connect the output of the Laser Module to GP5 of Raspberry pi Pico. Connect their VCC & GND Pin to 5V (VBUS) & GND Pin of Pico respectively.

MicroPython Code/Program

Open your Thonny IDE & Copy the following code & paste it to the editor window.

Now you can run this code to test the working of the circuit.

Aim the Laser Light at LDR so that red light will always fall on LDR Module. At this moment the green light of the RGB LED will turn on.

When there is any interruption detected or when the laser light is blocked by falling on LDR, the RGB LED will blink red & blue.

Working of Laser Light Security System

The project basically works on the principle of interruption. If by any means the LASER light is interrupted the LED start flashing. The laser is a concentrated light source that puts out a straight beam of light of a single color.

The LDR is sensitive to light and puts out a voltage when the laser light hits it. When the laser beam is interrupted and can’t reach LDR, its voltage output changes, and eventually the LED will flash.