I have posted a new version of GPS-Speedreader at github.com/prichterich/GPS-Speedreader that supports posting of Garmin 255 (and 255 Music) results to the GPS Team Challenge web site. Only results from .fit files that were recorded with the required settings (all GNSS systems + multiband, activity with minimal filtering) can be posted. This release also contains other improvements and bug fixes; more details are at github.com/prichterich/GPS-Speedreader/blob/main/CHANGELOG.md

If you plan to post results from the Garmin 255 watches to the GPS Team Challenge using GPS Speedreader, please update to this version. Older version may give incorrect results, in particular for the 5x10 second category, since they did not take some peculiarities in the Garmin data into account.

Some basic help is at github.com/prichterich/GPS-Speedreader/wiki/GPS-Speedreader-Help

Thanks Peter, great stuff

Warning!
Apparently the 255 has it's antenna on the rim, wetsuit material next to the edge of the watch can ruin the satellite reception


This is enough to give bad readings, or none. Where the watch on top of any clothing, don't roll your sleeve up alongside the watch.

I've released a new version (3.0.2) that fixes a number of bugs, and handles "repeated" points (as seen in Garmin data) by interpolating the coordinates for single repeated points with speed above 2.5 knots. If speeds are repeated for these points, they are also interpolated from the neighbor points.

One of the bug fixes is for alpha proximity circles, which are now drawn to show exactly where the alpha is calculated. For 5 or 10 hz data, the change is quite small, but for 1 hz data, it can be quite visible (for the curious: the distance from the first selected point in the alpha run to the preceding point is included in the run, so the circle is centered on the first point before the first selected point in the alpha run; this means the crosshair, which is at the first selected point, is not in the center of the alpha proximity circle). This affects only the graphical display, the alpha calculation has not changed. Thanks to Daffy for bringing the issue to my attention.

Downloads are at github.com/prichterich/GPS-Speedreader

I have just uploaded a new GPS Speedreader version (3.0.4) to github.com/prichterich/GPS-Speedreader
This version has a new option to set the text size when exporting to Google Earth, and bug fixes and improvements for turn analysis. That includes the option to change the type of misclassified turns (e.g. jibes to tacks), and bug fixes regarding turn radius (was wrong if exit length was more than 50 m) and minimum turn speed (was wrong in some foiled tacks).

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decrepit said..
Warning!
Apparently the 255 has it's antenna on the rim, wetsuit material next to the edge of the watch can ruin the satellite reception


This is enough to give bad readings, or none. Where the watch on top of any clothing, don't roll your sleeve up alongside the watch.

I've just bought a velcro wrap to secure mine and haven't noticed any problems with the results ( very similar to the motion. )

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boardsurfr said..
I have just uploaded a new GPS Speedreader version (3.0.4) to github.com/prichterich/GPS-Speedreader
This version has a new option to set the text size when exporting to Google Earth, and bug fixes and improvements for turn analysis. That includes the option to change the type of misclassified turns (e.g. jibes to tacks), and bug fixes regarding turn radius (was wrong if exit length was more than 50 m) and minimum turn speed (was wrong in some foiled tacks).

There are a lot of downloads on the page.. which one do I use to update for windows?