On/off button for Raspberry PI 2

    This site uses cookies. By continuing to browse this site, you are agreeing to our Cookie Policy.

    • On/off button for Raspberry PI 2

      I have been using OMV 3.0.76 for a few weeks now and wanted to say that it been great.
      Love the easy setup and the user friendly GUI.

      I’m doing a project at the moment which is probably a bit different from the normal use case for OMV.
      I’m planing to have an headless raspberry PI2 which will be embedded into devices and running on battery.
      I already have the basic setup but now I’m trying to find a way to safely shutdown the PI by pressing a button, like an on/off button.

      What would best way to approach this?
      I’ve been looking some external board like this ATXRaspi but not sure about the compatibility with OMV.

      Any nudge in the right direction would be greatly appreciated.

    • Since my time is a bit limited just quick pointers:
      • Raspberries are the wrong devices for the job, choose A20 based Allwinner devices instead (these are tablet SoCs with a Power management IC companion that deals with batteries)
      • An Olimex A20 Lime2 provides full UPS functionality: you need only an attached LiPo battery, the board is designed with buck converters to provide power to a connected disk even when running on battery. Most other A20 devices simply suck here
      • On these Allwinner thingies you can use every GPIO to power down a board, just do a web search for 'acpid shutdown site:armbian.com' to get the idea. Most probably even the power button on the Lime2 can be used to generate the shutdown event (can be tested, just check the Armbian forum links)
      • The AXP209 PMIC provides you with detailed battery access so you can easily implement an emergency shutdown when battery capacity/voltage falls below certain tresholds
      See also: Which energy efficient ARM platform to choose?
    • Addendum: Since performance is not relevant for you (since thinking about Raspberries) the A10 Lime board would be an alternative. Only Fast Ethernet (350mW less idle consumption) but unfortunately Armbian phased out support for this nice little board recently and I also have no idea about an EOL date for it. Lime2 with A20 will be available for a long time since used in a lot of commercial devices.
    • Thank you for you answers @tkaiser.
      That Olimex lime2 looks interesting and acpid shutdown looks like the way to go.

      This board will be one of the component of this device and my battery pack will be manage separately, basically this board will only be used to access the files on a usb flash drive connected to it.

      My main concern are:
      - Heat, want to avoid having to cool down the board which is why I was using a RPI2
      - Size, for this setup i only need the board to have 1 usb and ethernet port and will need
      to desolder anything else that take to much space
      - Power button, being able to turn on/off the board from physical button
      Do you know any compatible board that match this?

      I had a look at NanoPi and Orange PI zero plus from your other thread but based on
      what i could find they both require a large heatsink and I wouldn’t have the space for this.


      The post was edited 2 times, last by modgeek ().

    • RPi 2 uses in the meantime the same SoC as RPi 3 which is simply allowed to clock up only to 900 MHz instead of 1200 MHz (to remain compatible with thermal and power budgets). The same 'strategy' works everywhere else too of course (on all OMV ARM images except Raspberries you simply adjust /etc/defaults/cpufrequtils to adjust clockspeeds).

      The NanoPi SoC placement is made with 'metal enclosure as giant heatsink' in mind (works very well -- see my ODROID HC1 review -- and I really wonder why other board manufacturers still use the stupid placement on top PCB side).

      Besides that I would still choose a design that can manage battery itself (so no need for a separate microcontroller), there are also A20 SoMs available if space is a concern and obviously this forum isn't the best place for embedded hardware discussions anyway :)

      The post was edited 1 time, last by tkaiser ().

    • Nice, didn’t think of this but underclocking the SoC make sense.
      I also came across another of your thread from armbian forum where you discuss underclocking a H3 board. In that case I’m considering going for a NanoPi M1 Plus which seems to have by default a power and reset button and is quite compact.

      The only issue now is by looking a the OMV source forge I couldn’t see an image for this board, do you know if there is a way to run OMV on it?

    • 'Power buttons' on boards that are not equipped with a PMIC (power management IC) are fake and there's a reason I babble all the time about Allwinner A20 ;)

      If you choose H3 board a power button doesn't work as expected since the vendor's idea how to fake power button functionality is to never really poweroff the board but instead do a reboot that ends up with the bootloader (u-boot) sitting there in a low power state waiting for someone pushing the button. Armbian (which OMV is now based on) replaced the vendor's outdated u-boot with most recent one and this functionality doesn't work there for a reason.

      So either follow the recommendation and choose an A20 board (or anything else you find with PMIC support) or be aware that stuff doesn't work as expected. OMV for any device where Armbian runs on can be built by using the build system: forum.armbian.com/index.php?/t…ges-for-sbc-with-armbian/

      In a few weeks when next Armbian major release is out it's also possible to do an armbian-config --> software --> Install OMV (way better than following outdated scripts that are shared here and there since taking care about maximum performance).

      BTW: In case further questions arise I think chances for good answers are higher in Armbian forum than here.