Circuit Lake

Electronic Project and Circuit Collection

Low-Cost Vehicle Security System

03/05/2010 Category: AVR, Project, Security System, Sensor

This vehicle security system built using Atmel’s Atmega8 AVR microcontroller, Analog Device’s low cost acceleration sensor ADXL311JE and Dallas semiconductor’s DS1973 iButton. The circuit powered by small battery power supply which is integrated with the unit.


The system works as follows, whenever Atmega8 detects the change in acceleration by continuously comparing the ADC count, it looks for DS1973 iButton with the identification number preprogrammed in MCU flash. If it detects the same then no alert will be generated else it activates the on-board siren to generate alert sound informing about the vehicle theft.

The unique feature of this security device is that vehicle thief can’t disable the system externally without opening the headlight where the device is placed, and when he tries to do that, the acceleration sensor detects unauthorized motion, thereby generating alert. This Low-Cost Vehicle Security System project is designed by Sunil Jha.

Telemetry Device
Project Detail and Documentation