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Reply With Quotei guess 50 mts would be at its worst, with just 1 satellite fix
NO WAY!!!! 50 meters would be something like 1 block. If the accuracy is 50 meters, the how do we get street level GPS navigation?
Is it because this receiver module is old?
i guess 50 mts would be at its worst, with just 1 satellite fix
50 meter accuracy for 15 bucks - that sounds about right. This is probably using an old gps chipset, which reads fewer channels, which means less accuracy. I didn't read the white paper - How many channels and what is the sensitivity? Those will determine how many satellites can be picked up.
As a comparison, look here at the current chipsets available. The newest Sirf III chipset has 20 channel capability and can do 10m accuracy or 5m with WAAS.
If you want accuracy, spend a little more.
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It says 12 satellite tracking channel.
RF Input 1575.42Mhz (L1 band) at level between -130dbBW and -163dBW
Looking at the spec sheet of the newer GPS receiver,
http://www.sparkfun.com/commerce/pro...roducts_id=465
they are tons better... Especially TTFF... under 45sec. That's fast.. this has 2 minutes.
I guess it'd be better to put this module inside the "Fake" shark fin antenna housing and mount it on the roof, and connect it to PC via RS232 cable. I'll have to remove headliner and drill a hold to do this, but that'll be THE perfect solution...
Thanks a bunch.
The ebay auction doesn't mention an antenna. You will need an antenna to go with this module - I hope you realize that. A good one will cost as much as the module, or maybe more. Oh and you will also need a voltage regulator since the module takes 3.3v and you'll probably want to power this from your car's 12v.
I don't think you want to run power and rs232 to your roof. You should just mount the module on your mobo or in your PC case, connect to a comm port, grab power from your PC, and then just run thin coax to the antenna mounted in the fin on the roof.
Just so you know, you can buy a 20 channel SiRF III based eval kit at Sparkfun, which includes the module, magnetic antenna, serial and antenna cables, voltage regulator, power supply, and backup battery for about $100. Which is probably what you'll end up spending on the ebay 50-meter special, once you add all the things that don't come with it.
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Yes I realized that Ebay auction is just for the module. I'd need an antenna, coax cable, Power supply etc etc... It was adding up quickly. So I decided not to pursue that route.
I will definitly take your advise and go with the kit. You mean, this kit. right?
http://www.sparkfun.com/commerce/pro...roducts_id=652
what's the battery (12mm Lithium Coin Cell Battery) for? is this something that keeps GPS active all the time so it doesn't have to "cold start" everytime you start the car?
The Fake SharkFin antenna seems to be big enough to put that active antenna. But here's the question. The antenna is said to be "magnetic mount" but I still need to run cables to it. correct? that means the cable somehow has to get out of the car through a hole. Where do you usually put that hole? Roof? window groumet?
Yep, that's the module I just ordered. But I got just the board since I already had an antenna and you don't really need the power supply if you connect it to your PC 5v. The lithium battery is to maintain power to the module so it can remember your position for a quick restart.
Since my PC is in the trunk, I ran the antenna cable out of there to the rear window and under the weatherstripping up to the roof. No holes to drill.
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