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I have a very strange problem that I cannot understand.

I am trying to put together a demo-laptop with QGIS and gps.

On other computers I have it working as expected, but on this particular box something is strange.

What I get is a gps position about 680 meters south east of my position. The position is fixed in QGIS, it is not "walking around" as expected. I see the altitude is changing though, but not lon lat.

I have tried both connecting directly through /dev/rfcomm0 and through gpsd, same result.

In other clients everything looks ok, like Foxtrot GPS and gpsmon. In gpsmon, and Foxtrot gps I get another position than in QGIS and the position in the other clients is moving around.

I have moved the laptop and tried at another location and I get the same behavior but with another position some hundred meters away.

I did get desperate and re installed the laptop, but get the same behavior.

I am totally confused. It cannot be a hardware problem I think since it is working on other clients in the same laptop. It shouldn't be a software problem either since I have re installed everything including the OS.

As mentioned I get it working on other computers with the same software.

My setup is: OS Ubuntu 11.04 QGIS compiled from trunk a few days ago

I can think of two reasons, but don't know how to search: 1) Something in my hardware gives another configuration when I am compiling QGIS than on the other computors 2) I have some software-package present (that I apparently also re installed in that case) that is interfering.

Any ideas is highly appreciated


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Based on my experience it could be the laptop is reading the gps data wrong. I have to use a serial to usb converter for my old garmin12. On my Win7 laptop sometimes it will connect the serial device as a mouse, which indeed operates as mouse, jumping around the screen and even grabbing things. QGIS is specific about the type of gps input. hth

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But then, why is it working on other clients on the same laptop? – Nicklas Avén Apr 24 '12 at 21:15

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