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Battery life, sleep mode, and LED usage

matt1matt1
in General
Hi,

In the sample metawear app, there is an option to set the colors and then hit a 'play', 'pause', or 'rewind' button as well as a 'save' button.

What is the affect of the activity flow as follows:

(device is advertising)
->Connect to device
-> set LED intensity level
-> hit play
-> hit pause or rewind ->light goes off
-> disconnect from device

will the metawear board go to sleep?

What I'm noticing is that my board is always dead. The battery lasts 3 hours at best on a full charge. It also takes FOREVER to charge back up (at least according to the mobile app the battery level is always really low unless i let it charge for 24hrs or so.

Am I doing something wrong? I soldered a 100mA battery that matched the product specs.

Thanks.

Comments

  • matt1matt1
    I have a feeling the board is just either a) continuing to cycle through some LED pattern even when the light is off or b) not actually going to sleep.

    Also, I'm using android to communicate with it - if that helps.
  • GuarneriGuarneri
    Matt,

    Are you using an aftermarket battery? I'll let our Android developer comment on your specific use case, but in general, we experience ~5 days of battery life with occasional usage of the accelerometer + vibrator + LED. The battery usually charges to full in about 2-3 hours for us.

    We plan to do additional power efficiency tweaks in the near future which will enable drastically increased battery life when the MetaWear is doing nothing, but it sounds like your issues are specific to your case.

    Thanks,
    Yu
  • matt1matt1
    Yu,

    I ordered my board and it did not come with a battery or any of the extra sensors. So I ordered a 3.7V 100mA battery on amazon (link below).


    The storefront has been updated since I purchased my board.

    At any rate, I soldered it on following the pin description in the getting started guide.

    A 100mA 3.7v rechargeable batter should be the same regardless of manufacturer. This battery is generally used on something like a quadcopter.

    Could you possibly explain the sleep process or direct me to some references I may have missed. I'd like to know how the device is supposed to be sleeping. It seems like it is always advertising (which means that bluetooth GAP is always on correct?) Is this working as intentional? 

    Thanks.






  • GuarneriGuarneri
    Hey,

    "A 100mA 3.7v rechargeable batter should be the same regardless of manufacturer. This battery is generally used on something like a quadcopter."

    Yes I agree that your battery should work. Is there any possibility that your battery is just defective if you're experience such a drastic difference in battery life? Have you used it for anything else or tested it in any way?

    "Could you possibly explain the sleep process or direct me to some references I may have missed. I'd like to know how the device is supposed to be sleeping."

    I sent your question to our hardware/firmware designer so they can give you an exact answer. I believe it currently uses the package and core power saving states available to the ARM cpu, but the device DOES always advertise.
  • matt1matt1
    edited November 2014
    Yu,

    I haven't tested it. I certainly haven't used it for anything else - I bought it new from amazon for the metawear board.

    I'm trained from a software engineering perspective - so I know hardware/EE basics (soldering, breadboards, basic circuits, EE fundamentals, writing some basic PLC code). I do have a multimeter, is there a certain kind of test to tell whether or not the battery is defective without detaching it from the board (I don't have a de-soldering kit)?

    This project is part hobby and partly for research purposes (I'm a professor). I just want to make sure that I can get a prototype working with metawear with a reasonable battery life before I buy a few more boards - so I appreciate you tracking down the hardware/firmware team to answer my questions 

    Thanks,
    MLH
  • GuarneriGuarneri
    Matt,

    I worked with our firmware/hardware team and found that the pause feature in the Android app does not put the LED into a sleep state and should not be used as a replacement for a "stop" LED function. We will work to address this issue ASAP.

    That being said, the power leak from this is on a much smaller scale than in the issue you are describing. So while I believe it could be contributing to your problem, it is certain not the only or even main determining factor.

    From the issues you are describing, we believe that you most likely have a defective battery. There are definitely tests you could do to confirm this, but it will be fairly time consuming and will probably require you to desolder the battery. I would like to propose a few options for you at this point. Please check your Private Message.

    Thanks,
    Yu

  • matt1matt1
    Good to know. I think the android UI is part of the problem then - since there are rewind (<<) play (>), pause (ll) and "Save" buttons. I was afraid it wouldnt be sleeping with those commands.

    Thanks a lot for the support - I'll check my messages.


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