Hi,

I am working on a GPS logger. The data is logging and writing to an SD card and everything is well and good in that regard.
The issue i am encountering is that the Latitude is repeatedly jumping around, but the Longitude is always correct. I am Seeing the latitude numbers jump from 45.0xxx to 45.5xxx and then also throwing in random groups of 53.9xxx. the 45.5xxx is correct but most of the data is logging at the 45.0xxx locations. The pattern of points matches how i'm walking around with the GPS during tests but i can't seem to rectify the issue with it wanting to log a bunch of points with the wrong latitude values but always the correct longitude. I am walking around in open areas with fine GPS reception on a Survey grade unit so the location shouldn't be the issue. It has been turned off and on many times, i tried leaving it in a single location for 10 minutes before walking it around to see if that helped and its the same.

Anyone else ever experience this? Anyone have any ideas as to what could be causing this?

Thanks!
Brandt

Update:
I set the device up for one hour intervals of data logging and drove it 10 miles away going home. It did some more of the half degree jumps in latitude as it has been but also made a nearly one degree jump in longitude on one logging point. Out of 18 or so logs it never put a point in the right place and always had at least one of the Lat/Long numbers screwed up.

Probably doesn't add much to the story, but i thought it was worth noting that the longitude now also has shown signs of jumping around. The interval at which data is set to log doesn't seem to really make any difference. It has been acting the same at 2 second, 10 second, 30 second and 1 hour logging intervals. The first six or so points also don't log any data no matter what the logging interval is.

Just sharing a little new info from yesterdays test in case it helps anyone think of anything.

Thanks!
Brandt