When vehicle crashed, this device will sent a SOS SMS message to predefined phone number with victim vehicle details, time and position (coordinates) of vehicle.
Microcontroller Board: Arduino Uno
GPS Reciver: http://www.rhydolabz.com/index.php?main_page=product_info&cPath=184_186&products_id=1313
GSM Module: http://www.rhydolabz.com/index.php?main_page=product_info&cPath=184_185&products_id=1080
Sensor for crash detection: https://en.wikipedia.org/wiki/Piezoelectric_sensor
GPS signal format details: www.gpsinformation.org/dale/nmea.htm