Warranty after fix for GTA02 GPS rework for SD card interference issue

-stacy slm3095om at Millions.Ca
Tue Aug 5 20:03:21 CEST 2008


Andy Green wrote:

> |                                                          Has anyone
> | figured out how to kick the GPS receiver into UBX mode? I would be
> | curious to see if that changes anything.
> 
> It's actually documented by Ublox in here (Okular eats it)
> 
> http://www.u-blox.com/customersupport/gps.g3/ANTARIS_Protocol_Specification(GPS.G3-X-03002).chm

I've been reading that, but have not had any success in getting any UBX 
output... I have managed to disable NMEA (both using $PUBX NMEA 
extensions and your UBX generator) but then I get no data on the tty.


> | Additional test results (from 20080802) are up at
> | http://www.millions.ca/~stacy/neoFreeRunner/gpstale.html

> Doesn't look a million miles away from being right... there are two
> outliers shown and I guess the filtered  NaN(s), but basically all the
> other samples are in a decent place.

Atleast one of the outliers had multiple samples, but I am suspicious of 
those being synthetic as well.

 From the bit of testing I have done so far, it would seem that heavy 
use of the SDCard can cause the CEP to increase by 25%-50% but it is 
still typically better than the reference receivers. I had hoped to do 
my next round of testing in UBX mode (if that solves the issue with 
samples coming faster than once a second). If I can't get that figured 
out soon, I will just configure the GPS to only emit GGA sentences, then 
I will only get one fix per second from gpsd.

-stacy




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