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What about Gradient Lag?

keoltag
over 1 year ago

Can anyone report if Garmin have fixed the issue that the 1030+ has with ridiculously long responses to changes in gradient?

  • 0 over 1 year ago

    I have decoded a .fit that had "Data Recording" set to 1s and went up the same hill. I went round a loop 4 times, but will only show 1 example here:

    TiSt 1025264248 s distance 2665.45 m altitude 604.8 m speed 3.592 m/s cadence 70 rpm
    TiSt 1025264249 s distance 2669.35 m altitude 605 m speed 3.9 m/s cadence 0 rpm
    TiSt 1025264250 s distance 2673.53 m altitude 605 m speed 4.18 m/s cadence 0 rpm
    TiSt 1025264251 s distance 2678 m altitude 605 m speed 4.479 m/s cadence 0 rpm
    TiSt 1025264252 s distance 2682.92 m altitude 605 m speed 4.908 m/s cadence 0 rpm
    TiSt 1025264253 s distance 2688.09 m altitude 605 m speed 5.179 m/s cadence 0 rpm
    TiSt 1025264254 s distance 2693.64 m altitude 605 m speed 5.552 m/s cadence 0 rpm
    TiSt 1025264255 s distance 2699.58 m altitude 605 m speed 5.934 m/s cadence 0 rpm
    TiSt 1025264256 s distance 2705.91 m altitude 605 m speed 6.336 m/s cadence 0 rpm
    TiSt 1025264257 s distance 2712.76 m altitude 605 m speed 6.849 m/s cadence 0 rpm
    TiSt 1025264258 s distance 2720.2 m altitude 605 m speed 7.437 m/s cadence 0 rpm
    TiSt 1025264259 s distance 2728.26 m altitude 605 m speed 8.062 m/s cadence 0 rpm
    TiSt 1025264260 s distance 2737.16 m altitude 605 m speed 8.892 m/s cadence 0 rpm
    TiSt 1025264261 s distance 2746.62 m altitude 605 m speed 9.461 m/s cadence 0 rpm
    TiSt 1025264262 s distance 2756.78 m altitude 604.8 m speed 10.17 m/s cadence 0 rpm

    As before I stopped pedalling at the top, which was 605M. You can see that it was recording every second. However it took 12-13 secs for the elevation to change, so basically no change from "auto" data sampling. The distance covered at 605M is approx. 75M, which I also watched on the screen during the decent. The reality it's not even 10M (you can see the pick-up of speed due to the descent).

    I haven't included all the other data as I think this is sufficient to prove that the data sampling frequency is not the problem.

    I think the conclusion must be that the GPS/GNSS chip(s) or possibly the main processor chip are not up to it. I do not see how Garmin can fix this to reduce the time-lag.

  • 0 over 1 year ago in reply to MikeF-Swiss

    For what I know is using the barometer/altimeter for this misure, like for the VAM, anyway It's not possible that the GPS is so poor, there should be some kind of filtering here.

  • 0 over 1 year ago in reply to Garmin-Matthew

    Hi Matthew,

    Didn't see you FAQ. However you cannot calculate the Gradient if the elevation is incorrect. See the examples of my rides posted earlier.

    Also note that computer processor chips work in nano-seconds, certainly not 5-15 seconds.

    On the GPS/Navigation side, you are not collecting very much data at all. In "auto" sampling mode it is often only after 20secs and more before a new data record is logged. If you look at all the .fit files, they are only Bytes & Kbytes large. 

    I think Gamin needs to come up with a proper answer to this problem, it is certainly not the amount of data you have to process. The problem lies in the fact that you do not have the correct altitude to be able to work out any change in elevation and subsequently calculate the Gradient.

  • 0 over 1 year ago in reply to MikeF-Swiss
    MikeF-Swiss said:
    The problem lies in the fact that you do not have the correct altitude to be able to work out any change in elevation and subsequently calculate the Gradient.

    That‘s the problem! Absolutly right!
    I did a test one year ago with my 1030+

    forums.garmin.com/.../1280179

    I did a test to show how big the delay is until the barometric altitude display on the Edge 1030 PLUS reacts.
    To do this, I used IQ Data Field HM's DIY to create an Elevation Graph recording layout.
    Then I put the Edge on the ground floor, waited for the elevation reading to settle. Then I started the data field and went up the stairs to the top floor. There I placed the device on a table.
    The duration of the climb was about 10 seconds.
    The Edge was already on top on the table when after another 10 seconds the elevation display rose.
    This resulted in a delay of about 20 seconds.

    A test on the iPhone with the phyphox app shows that this can be done much better with mobile devices.
    As you can see on the screenshot of the iPhone, the barometric altitude change reacts immediately.

    This is now only the delay of the barometric altitude display.
    For the gradient display, another delay is added.

    And the Garmin Edge models work with BOSCH barometric sensors, which are incredible sensitive! (1030: BMP390)
    www.bosch-sensortec.com/.../
    (I don‘t know which one is built in 1040…)

    PS - only by hearsay:
    iPhones use BOSCH, too…
    https://cliffmass.blogspot.com/2014/09/the-iphone-6-has-barometer.html

  • 0 over 1 year ago in reply to mcinner1

    In other words we can't do nothing about???!!!, if nothig has changed from the edge 1030+ until now, after over two years, what we can do?

    It's clear to me that someone in garmin has locked his mind to the idea that 10-15 sec it's good enough, even if all the other competitor do so much better!, after all they have been even stated officially that they can't do better than 10-15 sec to have a good slope reading.

  • 0 over 1 year ago in reply to Tecamach

    FWIW: As a possible workaround, there are a couple of IQ gradient fields that I've used on other Edge units that work significantly better than the native gradient field.  IDK about using them on the 1040, but it might be worth a look.  One is Sensible Grade but I don't think it's compatible with the 1040 yet.

  • 0 over 1 year ago in reply to MikeF-Swiss

    Interesting - does anybody know what the hardware (or methodology) shift was after the Edge1000?  I presume it is hardware or it would have been fixed by now. 

  • 0 over 1 year ago in reply to Tupolev144

    The 1000 used another barometric sensor.

    Curiously, the gradient lag on the regular 1030 Edge (with the current software upgrade) - while not as good as on the 1000, is nonetheless significantly better than on the 1030 Plus.

    Meaning that likely, it had a different hardware sensor.

    Too bad, so sad for 1030 Plus and now, 1040 owners. Unless one lives in the UK, where a class action suit against Garmin is proposed

  • 0 over 1 year ago

    This is really sad... have ordered the 1040 Solar especially to get rid of the gradient lag and now it is still an issue. Any chance to get the awareness of garmin with the 1040 again when they did nothing on the 1030 Plus?

  • 0 over 1 year ago in reply to tom.weiler

    The official position from Garmin it's clear, you can read about  from the post of @Garmin-Matthew, a lag of 10-15 it's the norm....

    Problably at Garmin would like the earth to be little flatter :-)