Step counter very inaccurate

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  • Hello,

    I've received my BangleJS a couple of days ago and I'm very happy about how easy it is to program. Unfortunately, for my applications, I would need a rather good accuracy for both steps and heart rate. Let's discuss step counting here.
    I noticed that the accelerometer does not include embedded step counting and that steps are computed by the Espruino firmware (here?). The algorithm unfortunately is very inaccurate: it waaaaaay over estimates my activity.

    Do you have plans in this regard? Maybe include an accelerometer with an embedded step counter in the next model (if any) ?

    If it helps, we are working on a C implementation of this algorithm specifically for microcontrollers and wearables. I can tell you when it's ready so maybe you could include it in the next firmware.

    Cheers.

  • There's another discussion open about this, where @Purple-Tentacle seems to be having some success when testing new code for this. Here:
    http://forum.espruino.com/conversations/­345358/

  • And yes, I am working on it right now.
    Hopefully this leads to something, as I want to distinguish between arm movement and real steps. As much as this is possible with a device worn on a wrist.

  • I'll check the thread, keep us posted. Our algorithm should be ready in a month or so. I'll keep you updated.

  • Hi all,
    our open source step counter has been ported to C and can be used in your project!
    Here is the repo: https://github.com/Oxford-step-counter/C­-Step-Counter

    There are some constants that need to be optimised because they depend on the actual hardware you use and the sampling frequency (we used 50Hz, but probably 10Hz would do anyway). See the instructions in the README. If anyone here wants to try including this in the BangleJS firmware, I'll be happy to help!

  • Hello people!

    I've found a surprising way top count steps implemented in JS: https://github.com/alexgibson/shake.js/

    Some people did a validation study here: https://www.ncbi.nlm.nih.gov/pmc/article­s/PMC6219786/

    I have looked at the code and it's basically a threshold on the difference between two samples. I doubt this is generalisable. In fact, the authors of the paper had to manually calibrate the threshold on each phone and walking style.

    I'll leave it here as a curiosity.

  • Hi! Sorry for not replying to this earlier - I'd be really interested in trying to get your oxford step counter in. Not sure quite when I'll get time but i've just added it as an issue in the Espruino repo: https://github.com/espruino/Espruino/iss­ues/1846

  • great!
    There is a bit of calibration to be done, so it's not just plug and play unfortunately. Happy to help!

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Step counter very inaccurate

Posted by Avatar for user107850 @user107850

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