When phone is called or texted, phone thinks it's vibrating. Instead it closes the contacts on the relay.
When the relay is closed, it allows 12v to reach a pin on the microcontroller.
No need for a relay. The controller can check if theres a voltage present on the wire that spin the vibrator motor.
When voltage is present, micro.. gets coordinates from gps dongle. (how?).
The controller can be programmed to read off the NMEA sentences from the GPS...This is in serial format normally running at 4800 baud.
Does the gps have to be in sight? Will kinda hamper the secrecy of the device.
No...it can be hidden under the dashboard as signals can still go through plastics.
If the phone can be controlled via its serial connection then it is so much easier. Such as picking up the phone, dialling a number and sending text all being controlled by the serial ports perhaps.
I need more info
EDIT :
Yup it is possible to answer, dial, and text via the serial port.
http://gatling.ikk.sztaki.hu/~kissg/gsm/at+c.html
Time to look more deeper into those AT commands
