I would like to make my Rpi Zero W execute a simple task (which takes an insignificant fraction of time to perform, <1s) using inputs from sensors exactly f times a day. I am wondering whether:

  1. there is a value f small enough to make it more efficient for me to turn the device on only for it to run the task and then turn off again, and

  2. if 1 is true, is it possible to schedule the Rpi to "turn off" (= make it consume the least amount of power possible) and "turn on" programatically? I assume that the process of powering the device on and off takes more power than keeping it turned on for the same amount of time it would take it to turn on or off, so what would the optimal threshold for f be?

  • 1
    Perhaps the Pi Zero is not the best choice for such a job. Why not make your own measurements when on and "off". I say "off" because the Pi Zero is powered while power is applied.
    – joan
    Dec 23, 2021 at 12:42
  • With as low as the power consumption is going to be on the Pi, what real problem would you be trying to solve? The reason that I am asking this is that any workable solution that you might find would add complexity, risk, and probably hardware cost to the solution and you need to fully consider what you gain in return for those costs.
    – Kyle Burns
    Dec 23, 2021 at 13:54
  • @joan I hoped that "periodic small jobs" is a common enough problem to be solved long before I happened upon it so that I found some help here easily, that's why I wanted to avoid making my own measurements before asking here. Dec 23, 2021 at 14:19
  • @KyleBurns I plan to make the Pi battery-powered, so adding a few extra days (?) can mean a lot to me. And as my question body specifies, I'd like to solve the problem programatically, that is, by scheduling some script on Pi to shutdown/reboot or reduce power consuption to the minimum possible amount which allows restoration to normal power consuption state without hardware intervention. Dec 23, 2021 at 14:21
  • @CaptainTrojan - turning off the device would be a bit of a challenge, but could be accomplished (but not without sacrificing your "without hardware intervention" goal) by triggering some sort of switching relay to cut off power to the Pi. Where things probably go outside the realm of making sense for your use case is that you would still need some second device always running to turn your Pi back on, definitely adding far more complexity and I suspect more power consumption than just leaving it on
    – Kyle Burns
    Dec 24, 2021 at 19:34


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