Good morning everybody, I acknowledge that my planned project i'm about to describe does not stem from your arena but I have noticed from the forums and blogs that this is a community that may be able to help me out with my project as I see that you all use components that I have beenr researching. In short, I basically plan to take an empty laptop shell (the laptop may be an old broken one or a brand new shell) and I then plan to be able to track this laptop when/if it is stolen. I would want to be able to track to the thiefs house/appartment/car/bag whilst they are on the street. This laptop will have no hard drive/cpu/memory etc but would artificially be weighed down to replicate a realistic weight.I appreciate that laptop computers are now being built with gps functionality inside them but this approach is too expensive and my laptop needs to be trackable even hen it is switched off. I have done some research on GPS chips and GPS chips that already come with a board that simply needs a power supply such as the ublox boards and the mediatek boards yourselves sell and I was wondering if somebody could recommend the best components based on the 4 general requirements below:-
(1) The laptop could sit for several weeks/months without being stolen so battery power to the GPS board is important. Whilst the laptop is static where I placed it, there is no great need for frequent GPS transmissions but once it is taken I would like to track it accurately. I was wondering what type of battery would I use to power the GPS board to acheive this requirement and is it fairly simple to connect the gps board to the battery? Naturally this battery has to fit inside the laptop shell and be rechargeable. It would be fantastic if the existing laptop battery could be used to provide power as this would make charging up easier.
(2) The laptop must be locateable indoors and outdoors as in theory, it could end up in a car boot/trunk loft/attic and I would also like to be able to track fairly accurately - anywhere between 1-5 metres would be great if this is possible. The ability to locate this laptop indoors in a fairly built up environment is crucial as this solution would be operating in a city.
(3) When the laptop is taken, I would like to be warned as soon as possible. I do not want to monitor the laptop for basic movement as this is inevitable but I would like to be warned if the laptop leaves a certain radius such as 50 metres. Is this possible and if so is this a function of the GPS chip/board or the software that is used to monitor the GPS chip/board?
(4) I would like the solution to be a silent one if possible. I presume the gps chip/board does not make any noise at all when given a power supply?
(5) The software used to track the laptop would ideally be useable with google maps.
I appreciate any guidance on any of the above requirements and recommendations for the best components or any opinions/advice that you may have.
Kind regards, Martin
Replies
Sounds like an interesting project. I recently built a project like this but to track bird migration patterns. I caught some hawks and put on GSM based tracking devices which send me an SMS with location information. I have an SMS base station setup with a program to log all the data so its not clogging up my phone. You have several options available for this kind of project and it should be fairly straight forward depending on budget. You have a couple of issues to sort through though. I assume the laptop would be inside and GPS has a hard time getting signal inside. This could make it very hard to track the device once its moved (stolen). Second issue is that you will need something to transmit the GPS information to you. Since you require transmission from indoors GSM is the easy solution. To solve the GPS being inside issue you need a triangulation method other than strictly GPS. You have 2 options for this. First option is to triangulate your position based on GSM cell towers. This works well but can be fairly inaccurate and this is what I use to track birds (accuracy is 0.25 miles to 5 miles depending on GSM tower concentration). Second method is to triangulate based on wi-fi signals. This is highly accurate but requires the unit to be in a fairly urban setting. If its out in the countryside this isnt going to work for you. Most people are using a combination of GSM triangulation, wi-fi triangulation, and GPS. For a GPS and GSM solution I would look at something like a Telit GM-862 which is designed for exactly what you want to do.
As for the battery I would plug the unit into the wall so that the battery is not being used until it is actually stolen. Once the charge cord is removed and its working on battery this could be used to trip the GSM unit to start reporting and alert you. SMS come in really fast so you would know within 30 seconds if it was taken. Then to conserve the battery I would have the unit report position every hour or so and then go to sleep in the mean time which would give very long battery run time.
I hope that helps and good luck with it, sounds interesting!!
Fred