Arduino Laser Security Alarm — a working tripwire you can demonstrate in seconds
This is the classic security project every electronics student wants to build, delivered fully assembled and mounted on a clean presentation board. A laser diode module throws a narrow beam across the protected area onto a light sensor module. As long as the sensor keeps seeing the beam, the system stays quiet. Break the beam — walk through it, wave a hand across it, open a door into it — and the Arduino instantly triggers the buzzer and prints the intrusion alert on the 16×2 LCD.
How the circuit works
- The laser module is powered from its own battery pack and aimed at the receiver across the board.
- The light sensor module reads the beam and feeds a digital HIGH/LOW to the Arduino Uno.
- When the beam is interrupted, the sensor output flips and the Arduino Uno detects the change.
- The Uno drives the buzzer to sound the alarm and writes the status to the 16×2 LCD.
What is on the board
- Arduino Uno R3 microcontroller board
- Laser diode transmitter module
- Light / laser receiver sensor module
- 16×2 character LCD display
- Active buzzer for the alarm output
- 9v battery and AA cell
- Jumper wiring, all mounted on a printed display board
Perfect for
- School science exhibitions and class demonstrations
- College and university semester projects
- Final Year Project (FYP) prototypes and vivas
- Anyone learning how sensors, interrupts and LCDs work together
Why students buy their project from Arduino Corner
Because it arrives working. You are not chasing loose components around the market the night before submission — the circuit is already wired, mounted and presentable. Come and see it running before you buy, or have it delivered.
Visit us: Smart Home | Arduino Corner, Shaheen Market, DAV College Road, Rawalpindi. Same-day delivery across Rawalpindi and Islamabad, cash on delivery all over Pakistan.
