Being able to measure open circuit battery voltage is great, but it would also be useful to measure current while the light is running. That in turn can map to battery runtime and/or lumens. I wonder if any existing boards can do this, e.g. if they have adc pins connected to the relevant sense resistors. If not, it could be a cool feature in future boards.

  • solrize@lemmy.worldOP
    link
    fedilink
    English
    arrow-up
    2
    ·
    edit-2
    1 year ago

    Thanks both of you. It was intended as a pure hardware question since I can make the software changes myself in principle. So I wanted to know if there were adc inputs on usable places for this on existing boards, and it sounds like there are not. Oh well.

    As for the FET in turbo mode, good point. I’m mostly interested in the lower levels though.

    I guess tailcap current measurements with a DMM are good enough for my purposes. It would just be cool if it were built into the light.

    • SammysHP@feddit.de
      link
      fedilink
      English
      arrow-up
      3
      ·
      1 year ago

      I guess tailcap current measurements with a DMM are good enough for my purposes.

      Only as long as you use a clamp meter.

    • thefreeman@lemmy.world
      link
      fedilink
      English
      arrow-up
      2
      ·
      edit-2
      1 year ago

      if you have an emisar light and can disassemble it, then you can try soldering an airwire from the sense resistor to the button LED pad (sacrificing it for that) or a free ADC pin, but that’s more difficult. If that cause problems with the current regulation, add a 10k resistor or the likes.
      with a linear driver Iout=Iin so it’s simple, with a boost driver Iin=(Vout x Iout)/(Vin x efficiency), thankfully Vin is already bein measured, Vout and efficiency need to be guesstimated.