Here is the block/connection diagram of DhruvTracker

I’ll be using GPS for getting location and GSM/GPRS to upload location to online database, so that current location can be checked using a web/mobile interface.

I am thinking to use PIC1846J50 microcontroller because it have two serial ports (one for GSM and one for GPS), ADC, I2C, SPI and USB. 64KB of code memory and about 3KB of RAM, CTMU (can be used for buttons)

Accelerometer will be used to monitor acceleration when brake is applied suddenly/collision or vehicle speed is increase. Depending on the acceleration value sensed, if high acceleration is measured tracker can send SMS/Call to emergency number with GPS coordinates.

I2c for communicating with ADXL345 accelerometer, SPI for MMC card, ADC to monitor internal battery voltage, so that if power goes out tracker can go into sleep and wake up periodically to maximize useage time on battery.

USB will be used to configure tracker, read/write mmc and upload new firmware to tracker.

I’ll be using sim900 GSM module, sim900 because of two reason 1. its cheap and easily available in my area and 2. it functionality can be extended as per need using its Embedded AT feature.

For GPS thinking to use FGPMMOPA6H module because of its small size, can be mounted as SMD device and it have inbuilt antenna.

Now I have to research for other IC’s and components to use with GPS, GSM, Accelerometer and Microcontroller. For the software side I am thinking to use online interface using PHP/MySql as backend, HTML5 Boiler plate and smarty for templates.

In my next post i’ll post the IC’s and components list which would be used to make a prototype of the above.