issues with the HRM

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  • Hallo people, I got my bangles on the mail this weekend and I'm enjoying a lot playing with it. But, I can't get any meaningful HR signal, it's always saturated. Could it be that my unit has some issue or its normal?

    I'm adding a representative image of the kind of signal that I get. The raw data is always either 100 or -2.

    I'm using the 2.08.189 FW but even before updating to that it wasn't getting anything too different.

    Any help is appreciated!

    Mucha suerte!

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    • 20210301_190814.jpg
  • Hi, That's a tricky one - it definitely looks broken. However I just checked on a Bangle here and that HRM app does now seem to have some issue with graphing the data. I'll look into it and will get that fixed - maybe when it's sorted you'll be able to see slightly better data.

    You mention the raw data - you actually looked at the data from the HRM event and you're sure that the only stuff in there is -2 or 100? It seems pretty odd - and it'd be hard to imagine a hardware failure that caused those readings so it could just be software.

  • Many thanks for the reply! The raw values where from some of the HRM monitor apps, not me reading them from the event.

    I'm attaching a 1 min file that I just recorded with the HRM Data Exporter app, while my arm was resting on a table and trying to keep it as calm as possible. It's not -2, 100, has a bit more values, but still saturated data that doesn't look quite appropriate.

    Importantly, I'm almost totally sure that I'm still alive and that I have a pulse, will ask around just to be sure.

    Do you have any ideas about what could be happening?

    1 Attachment

  • Ok, thanks for that dump - yes, that does look wrong to me.

    Normally the heart rate monitor takes a few seconds (maybe 20?) to adjust itself and start getting correct readings, but it definitely looks like in your case it's not managing to do that.

    Where do you live? What I usually say when there's some problem like this is if you could take the straps off the watch (instructions here) and then just post it back to us, untracked, in a Jiffy bag (shipping is cheap that way), I'll get a new watch body in the post to you.

  • But, what's the procedure, wait for my unit to arrive and then sent the other?
    This is going to take a little longer than expected. I'm currently living in Lisbon, and from UK to here it took some 2 weeks and then customs, I guess if it's no tracked it could take less, but I can't assure you that it'll reach you soon.
    Unfortunate amount of messines, but thanks for the amazing response and availability!

  • Ok, no problem. As long as I know you're going to send it back I can get one out to you now, then you can swap over when it arrives. I'll drop you an email now

  • Already replied,

    Many thanks, I hope to be posting here soon enough with some code and more,

    Mucha Suerte!

  • Hope your new watch works ok when you get it, FYI on the HRM data exporter app specifically, the -2 doesn't relate to your heartrate directly but the signal from the sensor so it should oscillate somewhere between I think -4 and 4 in normal situations, so your log does look bad but only because it doesn't fluctuate much rather than there being low numbers. Sometimes with mine I do have to adjust the position etc to get good readings at times and it can be sensitive to movement.

  • Took me long enough to report back!

    After some emails with Gordon, I got a replacement watch that is working. I'm able to see a signal that looks quite like a pulsating heart!

    Many thanks for the help and prompt solution,


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issues with the HRM

Posted by Avatar for mauro.toro @mauro.toro