MetaBase does not create data files

I'm using 2pcs MMR sensors (grouped together) with MetaBase app (latest version installed May 5th). Recording mode is "Logging" + "Acc" + "Gyro". Everything goes now normally until the "Session" needs to named. When pressing "OK", the app "drops down" in Android UI. When reopened, in the "Session"-list there is the name of data with details, but the "Download" folder is still empty. See pictures attached.

Several trials have been made. Sensors reset etc. Firmware updated


  • Which Android and which device are you using?
    Starting with Android 10, using internal storage is no longer allowed. So you can only access the files through the App.
    This is 100% normal and is 100% the new google android rules moving forward for all Apps.

  • We are using Android 10 in Nokia 7-series phones. They are equipped with pure and clean Android, which should be most reliable version.
    Few weeks ago the data was stored in the "Download"-folder, which is very practical for our own use.
    Now there's still problem that trying to export data via MetaBase app, only one file can be send to Google Drive or using Gmail. The Drive sharing offers "... + 3 files", but only one is moved to Drive. Gmail sharing shows only one file and gives warning "Unable to attach file".
    We measure Acc & Gyro data from two MMR sensors at a time, so 3 out of 4 files remain in the app without use.

  • So the issue is when you bundle/group sensors?

  • Yes, we need to measure wrist movement parameters (angles, angular velocity, repetitions etc.) from two MMR sensors grouped together. MetaBase creates four separate csv-files (2Acc + 2Gyro), but only one of them can be exported. Therefore our algorithm can not calculate anything.

  • OK I will see if I can reproduce this issue.

  • It seems I have a similar issue

    I use a group of two sensors.
    At first attempt only one downloaded I got one green "V" and an invite to try again.
    At second attempt the second one downloaded. The I got a second "V"

    I was asked to give a name. But no file appeared in the bottom part of the screen I always have the "Download" tag at the bottom of the screen.
    When I press on it, I see the name of the two sensors with a green"V" on each line

    So I cannot get the data and I cannot start a new cession !

  • Hey i just released 3.4.19 Metabase. It should be available shortly. Please try it out and let me know if it works for you.

  • No improvement.
    It still have the "download" tag at the bottom of the screen and when I pressed on it at the first time after upgrading , Metabase
    I got "no logged data" for the sensor that downloaded at first attempt with previous metabase realease
    I got a transmission and was asked to give a name after the second sensor has downloded

    But when going back to the cession screen, no csv file and once again the "download" tag at the bottom of the screen

    so I have two problems :
    1) it seems my data are lost and it was valuable data collected on top rank athlete
    2) I cannot use the sensors for 10 days now

    So at least is there a way to "reset" the sensors ? Up date firmware 1.5.1 is installed) ?

  • edited May 2021

    Hi Eric,
    Did you make sure to delete the MetaBase App first? You need to delete in completely before you install the new version.
    Next try again with just one sensor doing something simple like stream acc data for 25 seconds at 25Hz. Then just export the data by emailing it to yourself.
    Tell me exactly what happens when you do that and try to export the data. Please include videos and pictures because right now other users are not reporting issue and neither am I so I need to know if this is something specific to you and your usage.

  • Yes I did delete the App prior to install new version.
    When I first open the App the devices are still in a group

    I cannot make any logging or streaming. The only proposal I have is "Dowload"
    and when I press on "Download"

  • Delete the group and gather data from just 1 device as per my previous instructions.

  • Here is what I get

    I can configure and obtain a log file from "E6" device
    when I go to "FC" device I am at the same point

    Notice this is specific to the app.
    I could configure and read data on both devices using Python API. At the end of API cession I rest both devices but this doesn't help when I go bask to the app.

  • Hey @ericf
    Sorry but I am having a really hard time understanding the issue. Maybe you can show me a video?

  • I had to delete the devices also and then connected them again.
    It works and I can log data on both devices now. Files are created
    But when logging accelerations on two devices with same parameters (range frequency). Downloading take 20 s from one device and about 10 mn from the other device.

  • Hi @ericf,
    That's normal because the latest Android SDK requires that each App have its own storage that is not accessible by other Apps.
    BLE is inherently slow so that is normal. It may look like 20s on one device and 10m on the other but it's not, it's about 5m per device.

  • No it was not 5 mn per device.
    I made a test with only one device active and logging. And for one of the downloading lasted about 20s and on the other one 10 mn.
    More surprising, problem has gone ! And now downloading (short) time is similar on both device.

  • @ericf,
    Based on your description, it seems more likely one of the sensors had some extra leftover data in the memory that it needed to download.

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