Experience with Parallax GPS receiver module

aviator3.1

I just purchased the Parallax receiver module (Item code 28146) and was wondering if anyone had any experience with it. I copied over the demo code from the website and am communicating with the BS2 and getting all the right displays in the debug window.

Every now and then I will acquire a signal and get some readings but even in clear view of the sky it is jittery. I did some research on the module before purchasing it and noticed it used the SiRF III chipset which appeared to be a very well known and reliable chipset but why can't I seem to acquire a signal even after waiting up to 15 minutes. Would this have anything to do with the antenna that is mounted on the module? I'm running it with the /RAW Pin pulled low to continuously monitor incoming data. Also I'm only interested in monitoring speed, lat, and long, though I don't think that would effect how the receiver links up with the satellites.

Any ideas on how to obtain a stronger or more reliable signal? Would a different antenna help?

Thanks

Phil Pilgrim (PhiPi)

How close to your BS2 is the GPS module? I've found that physically separating the micro and GPS a little helps with signal acquisition. The signals received from the satellites are extremely feeble, and any RFI emitted by a very proximal microcontroller can adversely affect reception.

-Phil

hover1

I use the same GPS module on a GPS Data Logger, but with a Propeller on a Propeller Proto Board. I have found that readings will not be acurate unless you are moving. I have logged location information at a stand still for 30 minutes, and the readings, when plotted on Goggle Earth, can be off by hundred's of feet. But I'll take a half hour ride in the car, and readings will be at the advertised accuracy, while moving. The antenna seems to be good enough while sitting on the dashboard of the car.

Try and take some readings while moving.

Jim

aviator3.1 said...
I just purchased the Parallax receiver module (Item code 28146) and was wondering if anyone had any experience with it. I copied over the demo code from the website and am communicating with the BS2 and getting all the right displays in the debug window.

Every now and then I will acquire a signal and get some readings but even in clear view of the sky it is jittery. I did some research on the module before purchasing it and noticed it used the SiRF III chipset which appeared to be a very well known and reliable chipset but why can't I seem to acquire a signal even after waiting up to 15 minutes. Would this have anything to do with the antenna that is mounted on the module? I'm running it with the /RAW Pin pulled low to continuously monitor incoming data. Also I'm only interested in monitoring speed, lat, and long, though I don't think that would effect how the receiver links up with the satellites.

Any ideas on how to obtain a stronger or more reliable signal? Would a different antenna help?

Thanks

aviator3.1

Ok, the GPS seemed to work relatively well while moving. Since this product will be in the car and not necessarily on the dash does anyone think a more more powerful antenna will help in acquiring the signal? If so does anyone have any experience with using different antennas on this unit?

Thanks

kf4ixm

aviator3.1 said...
...·does anyone have any experience with using different antennas on this unit?

I asked the same question in the sensors forum a few days ago, with no responses. im sure theres someway to take the patch antenna out off the reciever circuit and replace it with another type of antenna·without damaging the module, i would just like to hear how someone else (if any) accomplished this succesfully.

Post Edited (kf4ixm) : 1/19/2010 10:24:00 PM GMT

aviator3.1

Thanks hopefully someone replies soon.

Franklin

You will have to find a different module or try it yourself. The GPS and antenna are designed to work together and you would probably destroy it just getting it apart.
If you try let us know how it went.

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