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Distance totally wrong

viliharb
over 4 years ago

Hi,

I did a short hike (I was walking, not bilking, Garmin Edge 830 was on the top of my backpack) and the distance displayed by Edge 830 was totally wrong!. I know that correct total distance is about 11 kilometers, but Edge 830 displayed 4,75 km. I compared this to my daughters Garmin watch and her distance was about 11 km (which is correct!). The distance calculated by Edge 830 is also displayed in Garmin Connect and in Strava. I believe that this data is written in FIT file and transferred elsewhere. 

And now the surprise. I exported GPX data for the hike and import the file in different GPX viewers - they all calculate the correct distance (which is 10,9 km). So I can conclude that the GPX points are stored correctly (I use 1 second interval), but Edge 830 for some reason does not  sum the distance correctly.

To summarize:

1) Garmin Edge 830 displays wrong distance on several occasions (I have described  in detail just one instance -  4.75 km instead of 10,9 km. 

2) This (wrong!) distance is transferred to Garmin Connect and Strava (very probable by FIT file)

3) All GPX points are correctly recorded by Edge 830 and the distance calculated from these points using  different apps on www is correct.

Any suggestions? Advice? 

Best regards, 

Viljem  

  • 0 over 4 years ago

    Do you have auto-pause enabled? The Garmin will then not register below a certain speed, which might well happen when walking?

  • 0 over 4 years ago

    I would guess this has something to do with auto pause as mentioned. Can you please record a cycling activity with your Edge 830 with auto pause disabled and post a fit file if you are still having issues?

  • 0 over 4 years ago in reply to Garmin-Duncan

    For walking I use Activity profile named Hoja (which is Walking in Slovenian). This profile has AutoPause=OFF, AutoSleep=OFF, TimerStartMode=Manual.

    I have attached ExportOriginal from Garmin Connect.

     4505605443 (1).zip

  • 0 over 4 years ago in reply to viliharb

    Any word on this? I have the same issue. It happens both when I use a profile with auto-pause off, or walk without choosing a profile.  I lose 20-50% of the distance. Happens with walks in my small town, and in the woods. I've tried it with both GPS, only, and with GPS+Galilao; all with the same inaccuracy. Looking at the speed profile, its constantly dropping to zero, though I'm not stopping. I, too, have it set to 1 second. Biking works fine.

  • 0 over 4 years ago in reply to patsdiner

    My guess would be that this happens when the GPS signal is not well captured by the Edge (device not well exposed when walking, or when reception is not good due to environment, like trees). I had exactly that with a Garmin Edge 810, when biking in the woods - except in winter when the trees didn't carry leafs.

    I suspect/conclude that such drop-out of GPS signals are not properly compensated in the Garmin software. If the device e.g. doesn't get a signal for 50m, it simply doesn't count that distance - while the software should be clever enough to conclude that I have effectively moved 50m when I am 50m further away when signal reception is again OK a few seconds later. I have seen exactly the same issue while biking with my Edge 830: it showed the correct distance in open air, but too short in the woods. Until I mounted a speed/cadence sensor. From that point on, the Edge relies on that sensor (i.e. the wheel rotation) to determine the distance, and no longer the GPS position.

    So if for you the Edge reports the right distance for biking but not for walking over the same route, it either means that the way your carry the Edge while walking is not as exposed as while biking, or that you have a speed sensor mounted on your bike. But as I said, I suspect that Garmin could go a long way in its software to compensate for poor GPS reception, but so far it doesn't ...

  • 0 over 4 years ago in reply to patsdiner

    I would say that is correct. I uploaded the activity and it appears to be through a heavily wooded area. The GPS track is visible in the .fit file but hardware on the device appears have been having a difficult time recording it. Our solution would be to install a speed sensor on your bike when using your Edge device in heavily tree covered areas. However since you are walking with the device that is not an option.

  • 0 over 4 years ago in reply to Garmin-Duncan

    The "small town walking" I speak of is in a Jersey shore town. There are probably more seagulls between me and the satellites than trees.  Viliharb reports its a file interpretation issue.  How does this get moved beyond "my guess..." and go to actual troubleshooting/fix? Do I really have to buy a wheel magnet to do what my $400 device can't?

  • +1 over 4 years ago in reply to patsdiner

    p.s. If I were to guess, the 830 developer never considered the device would be used for walking (hence the inability to pick "walking" when creating a profile).  That being the case, the programmed interpretation of the file is probably assuming 6+ mph speed. When below that, it assumes the user has stopped.  It the program allowed for a slower pace, it would probably work.  I've programmed for 30 years, and there's nothing better than fixing a bug for us guys, if someone reports it to us...

  • 0 over 4 years ago in reply to patsdiner

    p.s.s. (sorry) Original post said Garmin watch correct, Garmin 830 incorrect. Same path, different results. Compare and contrast, fix the latter.

  • 0 over 4 years ago in reply to patsdiner

    p.s.s.s. Viliharb, here is the (unfortunate) work-around.  Once the activity is in Garmin Connect -

    1) display the activity, click on the gear icon

    2) download the activity as a .gpx

    3) go to your dashboard, click on "activities"

    4) click on import, browse, and upload the file you just downloaded.

    The distance is now correct.