connecting GPS and GSM

[jijoyattitude]

sirs,
I am doing a project and wanted to get some help in it...

Suppose i want to track the speed of a car(digital speedometer or somehting of that sort) and the car has been given a speed limit...the car has been attached with a mobile module or mobile phone and i want to activate the phone to send me sms when the speed goes above the speed limit and later stop when the speed decreases to the required speed.

so this is the basic idea ..track the speed of car using digital speedometer and if speed is above specific speed activate GSM to send location of the GPS receiver in the car which is also attached....

pls let me know how to d it..iam not a master in electronics..just know the basics and got this idea in mind..would appreciate if you can help me in this regard as soon as possible ...

as far i know we need a digital speedometer...i microcontroller to activate the system..a GPS receiver to keep track of the location and a GSM to send sms but dont know how to make it work..so if you could help me in this matter


so pls let me know these ...

hoping for a reply

reagrds
JIJOY

 

[Eclipsed]

No need to post in 3 different areas.

 

[crust]

In the future please post your topic in only one forum. In any case, as a suggestion, you could forego the speedometer (and thereby any modification of the vehicle) and just use the GPS to compute the velocity in addition to the location.

 

[jijoyattitude]

can i get the correct speed on the vehile using GPS if yes how can i get this??

how can i calculate froma gps..
i need an almost accurate speed as i want the system to work only if it goes above this speed

 

[crust]

Well a GPS gives you position which is accurate to 20m or so, it samples its locations several times a second at a fixed frequency, so you can then compute the velocity (velocity is the derivative of position with respect to time). Or, you can just buy a regular handheld GPSr like a garmin, magellan, etc. Through their serial port you can get the current speed without having to do the calculations yourself (you have to convert changes in lat/long to speed).