Cannot detect GPS Signal

**sanjaym** · 09-11-2007, 07:40 PM

Hi,

I have just installed CF and am having problems getting gps to work.

I am using a sirf gps receiver on com 6. I tried leaving it on for a while and still no luck.

Could someone point me to any programs which i can use to test the receiver? I see a lot of people use xport, what exactly will that do?

Thanks

**NiSlo** · 09-11-2007, 08:23 PM

Try GPSinfo. Open it up and select your comport and then start. You shoudl see the raw data coming in in lower most text box.

Xport basically creates a copies the data coming in on the physical port (com 1) and provides a second virtual port (com 2) so that you can have two applications reading the gps data at a time. If you try using two gps programs reading one port, one of the applications won't be able to read what's coming in.

**veetid** · 09-12-2007, 11:00 AM

also try NMEA mode at 9600 baud, you should be able to switch your receiver to NMEA mode, if it didn't come that way by default...

david

**sanjaym** · 09-12-2007, 03:50 PM

I have tried gpsinfo and freegps. Xport is also seeing the data from the GPS, but i still cannot lock onto any satalites. Is there a specific port that works best (although i am using low ports). Also the GPS is a usb device if that makes a differance.

Thanks

**sanjaym** · 09-12-2007, 04:02 PM

How can i switch it to NMEA Mode? Do you mean in CF?

I have tried xport, gpsinfo and free gps and all see the data from the gps but cannot lock to the sats??

**veetid** · 09-12-2007, 04:14 PM

I mean in CF... you receiver might be Sirf, but it might have come in NMEA mode by default, many do... Also NMEA mode in CF is more compatible...

if it is already set to NMEA, try switching it to SiRF, also best to save changes, exit Centrafuse, and load it again...

then try some Baud Rates, try 9600 with NMEA first, but you can also try 38400

david

**sanjaym** · 09-12-2007, 05:19 PM

Still no luck. Its not a prob with cf i dont think, because i cannot get a fix using gps info. Any other idea's?

**NiSlo** · 09-12-2007, 09:37 PM

Where are you testing this? (Home PC or in the car)
If in the car, is the car in the garage or outside on the street?
Where is the gps receiver located?
How long are you waiting before you decide it's not going to get a lock?

You will see 'empty' raw data coming in even if the receiver isn't getting any signals from any of the sats.

**sanjaym** · 09-13-2007, 10:29 AM

I am testing in the car. I have the GPS receiver outside the car on the roof. I have left it on for around 15 mins while driving around.

Could it be a faulty receiver?

Thanks