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Pitmairen / bryton-gps-linux

An attempt to read Bryton GPS devices on Linux
GNU General Public License v3.0
29 stars 14 forks source link

Distance value from speed sensor in Strava (or tcx #14

Open pstasek opened 11 years ago

pstasek commented 11 years ago

Hello,

first of all I would like to thank you for a great support for bryton gps devices on linux.

I have a Rider 40T (includes a speed/cadence sensor), and I noticed a different distance value of my last workout shown by a "--summary" parameter and a computed value that Strava shows on activity page. The difference is about 4 km on a 74 km long track. Data from speed sensor are more acurate with proper wheel size setting. Is there any possibility to upload the summary values if they are present?

The dump file including these data can be downloaded here: https://dl.dropboxusercontent.com/u/2708715/dump

it is the last workout with number 0.

Thanks, Petr

Pitmairen commented 11 years ago

The values uploaded to strava is the values that are recorded by the device (the same as in the summary). I think strava ignores the distance value that is uploaded and calculates the distance from the gps trackpoints, but i haven't tested it that much.

But i thinks there is a bug on the device when recording laps, the last lap summary sometimes seems incorrect. Currently when uploading to strava the lap summaries are included, it's possible this could cause the difference in the distance if the lap info is wrong. I will tests this after my next ride to see if removing the lap info will make a difference on the distance on strava.

pstasek commented 11 years ago

I'll try to test laps recording on some short multilap track, and see, if the distance will be the same, and post a dump here.

Strange thing is, I tried to sum distances of laps in this particular activity, and it shows 76.2 km, so it is 10% difference, so it really looks like strava ignores the distance uploaded, and computes this value from trackpoints :(