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  • Powering BelaMini from LiPo or 3x AAA

what I am experiencing is slightly different from Robin and its more related to battery than microphone(I think) because I am able to get a healthy signal from MEMS using this circuit diagram. The DC offset is adjusted with low pass filter in my super collider patch to be clear, and Here’s to an example recorded yesterday with the same MEMS microphone.

I think my issue is more power related because I am experiencing unexpected shutdowns before bela is properly booted When it’s powered by Lipo battery or 3 AAA BATTERIES. When the booting starts, I can hear a short click in the audio, probably indicating that there’s power running, but the bela doesn’t stay on. A similar thing happens when I use three AAA batteries with a battery pack Like this https://www.allekabels.nl/batterij-houder/1062/1283175/aaa-batterij-houder.html

A short video on problem I am experiencing here.
https://www.dropbox.com/scl/fi/nvv4uhttnk0fogpr8ki8f/Video-26-02-2024-8-56-34-PM.mov?rlkey=69ott7cyhuhtti47ljwluw5l5&dl=0

Do you have an idea what the cause might be?

Thank you!

    scmint The DC offset is adjusted with low pass filter in my super collider patch to be clear, and Here’s to an example recorded yesterday with the same MEMS microphone.

    OK that sounds fine.

    scmint When the booting starts, I can hear a short click in the audio, probably indicating that there’s power running, but the bela doesn’t stay on.

    Is the short click in the audio as soon as you plug the power in or does it come in about 10 seconds later? The latter would be the Bela program actually starting.

    As to what's causing the power issue, it's hard for me to see how your battery is connected. Can you please follow the instructions here : connect the battery's + to P2.14 and the - to any GND pin on P2. Remove your control panel for now and only plug the battery directly to the board. Ensure the battery is fully charged. If the problem persists, you'll need to access the boot log via UART. Have you got a USB-UART adapter and/or another Bela that you can use for that purpose?

        Hi Giulio, thank you for this quick response.

        I don’t have usb to UART adapter but I have another bela on beagle bone but not sure how to access the boot log with this? Would you mind further describing how this might go about? Also, just to double triple check, what are correct way of indicating the pin column numbers? Maybe I am reading it not right but the diagram here only has pin names… https://learn.bela.io/pin-diagram/

        Much thanks again!

        Hi Giulio,

        thanks again for this instruction. just to double check I understand you correctly about this
        "connect the battery's + to P2.14 and the - to any GND pin on P2"
        So PB is actually plugged to the + of battery? This was confusing to me in the bela lipo battery instructions page.
        And I have been just jumping that to another ground to just get the bela booted

        Sorry my mistake, let me fix that:

        The battery's + should go to P2.14 and the battery's - can go to P2.15 or, equivalently, P2.21.

        Hi Giulio, I am trying out options with booster + lipo. In this case the powering voltage is 5v and wondering if I can still use the bat+ terminal or should I use vin terminal to power the bela mini?

        Thank you!

        5V into the BAT+ input is OK. Unless there is some charger support in your booster, you should not connect the 10k resistor to BAT.TEMP , or that would try to charge it when powered via USB, with unknown consequences.

        Ok so not to charge it internally via bela through usb with 10k resistor or not to connect through usb when it’s charging simultaneously with the booster/charger . But using the charging function of the booster alone is OK, right? Just to be clear.

          scmint Ok so not to charge it internally via bela through usb with 10k resistor or not to connect through usb when it’s charging simultaneously with the booster/charger .

          Do not install the resistor so that it doesn't try to charge it as that could damage things if the booster is not designed for that.

          scmint ut using the charging function of the booster alone is OK, right? Just to be clear.

          I guess so? What booster are you using?

              The pdf and pictures that come with that one cannot be called "documentation".

              It seems that battery charging takes place via the USB of the booster itself; you connect the battery to BAT- and BAT+ of the booster and the booster's VOUT- and VOUT+ to GND and BAT.VIN of BelaMini.

              @scmint also CRUCIALLY, verify the voltage between VOUT- and VOUT+ and make sure it's not higher than 5V before you plug those into BelaMini. The trimpot on the boards seems to be used to adjust that voltage across a very wide range.

              Also, check with a multimeter while everything is unplugged whether the VOUT-, VIN-, BAT- and the USB port's case are all connected together.

              Yes there is a trimpot that regulates the voltage there. Will make sure the voltage is at 5vdc before plugging the bela in

              5 days later

              Hi Giulio,

              another question that is kind of related to lipo battery. what is power consumption of bela mini?

              thank you

              on its own of is this with pocket beagle?