GPS without Reciever?

[imablackhat]

I just read over TOM TOM, etc, and I realize it uses a COM port when you plug it in the reciever (usually in your car), im wondering if this is a required thing. Can't I just install TOM TOM and on the go, connect to GPRS and find where I am? How does this all work?[/code]

[3waygeek]

TomTom, like all the other nav programs, expects to receive GPS data, usually in NMEA 0183 format (a simple text-based protocol). Most GPS units provide a serial interface, since it's cheap and is supported by just about every computer around, so that's how the nav software expects to read the data.

If you could somehow get location info from GPRS or from the GSM signal itself (look around here for a program called Cell Profiler -- it does something like that), then translate it to NMEA format and spit it out a fake comport that the nav software could read from, that'd work, but it's a lot of work, and won't be nearly as accurate as a good GPS.

GPS units are pretty cheap -- I've seen wired ones in the $40 range, and even the best BT ones can be had for $150. Compared against GPRS charges, it's quite the bargain. I've used an Altina GBT708 BT GPS for several months, and it works very well even with the SX66's subpar BT implementation. I'm about to upgrade to a Globalsat BT 338, which is supposed to have much better GPS reception.

[silent_killa]

Im afriad not mate. But if you want to use it on the go, i.e. "Foot Patrol" instead of in your car then go for a bluetooth gps reciever. I recommend the new ones that use the SiRF Star III chipset. Heard their meant to be pretty good.

Hope this helps.

[evilc]

globalsat BT-338s work great with a BA