ATX Raspi is a smart power source for Raspberry Pi


One aspect of the Raspberry Pi that has always challenged us is the power supply. It was a great idea to power the board from a standard micro-USB port because economy of scale makes phone chargers (even in the 1A range necessary for stable operation of the RPi) cheap and easy to acquire. The thing we miss is the ability to power the device on and off using the built-in hardware. The quandary has given rise to many different solutions, and the ATX Raspbi smart PSU is one of the better ones we’ve come across. It’s a nicely packaged take on the PIC-based version we saw earlier in the year.

The device is a small PCB that acts bridge between the micro-USB power supply and the RPi board. It offers several breakout headers, one of which is used for a power button. The button is monitored by a microcontroller that switches the on-board relay accordingly. But it won’t just kill the power when you want to shut down. It first signals one of the RPi GPIO pins, causing the OS to execute a shutdown script. It then monitors the RPi for the shutdown tasks to finish before cutting the power.


  1. no says:

    ATX is a power supply standard. This is not ATX, and should not be called ATX. It’s interesting, but soured by the poor choice of a name.

  2. Per Jensen says:

    ATX (Advanced Technology eXtended) is a computer case spec. and has NOTHING to do with this!

  3. Alex says:

    I love the lack of constructive commentary, great project, AND GREAT NAME!

    • MrX says:

      Saying that the project name does not make sense because reasons X and Y and suggesting a name change is constructive criticism.

      Ironically, it is YOU that did not provide a constructive commentary.

      To prevent me from falling in the same fallacy: I love the form factor of the board. To make this even more awesome, I would add a RTC to the board and allow it to power on/off the RasPi at specified times. The bootup time could be set, by bitbanging a GPIO, for example.

      • Luke says:

        Unfortunately, we live in an era where word meanings no longer matter, It’s as if many people seem to think that Humpty Dumpty’s statement that “When I use a word, it means just what I choose it to mean — neither more nor less.’ is some sort of gospel. Clarity and understanding are irrelevant.

        • smilr says:

          Clarity and understanding indeed, when I first heard this name I had expected it to be some sort of adapter that would allow one to connect a raspi directly to the main power header of an ATX power supply, and use the raspi to soft power on / off said supply.

          This name leads to confusion, I agree with those suggesting it be changed.

        • There are also metaphors. Not everything is literal. Imagine that.

        • David says:

          Just yesterday I was perusing the TV listings and saw a program whose description included “ACM Awards.” REALLY???? On ordinary TV???? Oh wait… somebody didn’t care that “ACM” was already taken.

  4. jh says:

    I just want the button

  5. Blorgassmorg says:

    This inspires me to use an arduino as a power supply for a 555.

    Anyone have a sketch I can use for that?

  6. lwatcdr says:

    Since you have a mpu anyway why not add a clock and a real bidirectional interface? You could do things like have the pi power up at a specific time.

    • Greenaum says:

      I’d hope that the mpu itself is powered off once the relay opens, with the pushbutton temporarily bridging the relay’s contacts to allow it to switch on. Otherwise, if the power circuit’s never truly off, it’s kinda pointless.

      Tho to be true to the principle, the relay should switch the power at the mains, before the phone charger or whatever.

    • treymd says:

      Or provide the ADC that the Pi is without.

  7. blade says:

    While I agree that calling it “ATX” has the connotation that it complies with that standard, I’m not sure there is anything else that gets the point across. It’s a neat project that I may end up getting a few of for my collection of Raspberry Pi’s

  8. Ian says:

    If I remember correctly won’t this bypass the main polyfuse? A USB B socket wouldn’t take up much more space than that SIL header and then you could use the conventional power input with protection.

  9. JimBob says:

    Hmmmm…I always considered the power connection the worst feature of the Raspi, followed by the dearth of I/O pins provided. To each his own, I guess.

  10. VeeBee says:

    This isnt anything close to anything ATX.
    its pretty much the idea of an ACPI shutdown though.

  11. Harvie.CZ says:

    What if i want to kill frozen raspi? I need to hold button even longer? Most PCs are issuing shutdown sequence at short press and forcefully disconnect power when holded for few seconds…

  12. Alex says:


  13. Andrew says:
  14. Addidis says:

    I made something similar. I just took a standard cd-rom power connector and a usbA and a nice big cap. The Pi is in my printer, so the PI is the 5v load (even though I have an expensive ATXpsu and don’t need a load) Rather than worry about shutting down the Pi I just get it all set up and image it. It autoloads octoprint , the web cam, the pi, the lcd, printer, and 100w stereo amp all from the ATX switch. I usually never do more than boot it on and print and power it off. If/when it corrupts the SD I will just reload the image.
    I had called mine the Pisupply, but I think I will change it to the ATXPiSupply. :D

  15. Karen says:

    It is just what I need. Bought two for current projects in the nick of time. Personally – I don’t care what you call it if it works.

  16. fartface says:

    It seems that people just dont get what the RasPi is for. You dont NEED to “shut it down” just yank the power. At least not if you did things right. If you did the newbie mistake of leaving a filesystem open as read/write on the raspi, I can see that.

    • NewCommentor1283 says:

      for once i agree with you

      everybody listen to what he just said.

      this is why assembler andor linux andor dos
      are so damm valuable in million dollar robots.
      instead of “breaking” and needing a service call
      once every few (*%!@*%) breaker-trips,
      it just needs to be powered back up and started!
      easy 20 grand saved.

      we’ll buy the maintence-free ones thank you!

      PS: a mantence call for a 1million dollar robot is NOT 100$ … lol

    • thedoktorj says:

      A Raspberry Pi is FOR whatever the hell you want to use it FOR. Just because you use it in projects that don’t require write access to the SD card, doesn’t mean everyone will. Many applications NEED to write data out without a separate server somewhere to send it to.

  17. bty says:

    and they also forgot the poly-fuse, which is bypassed when powering via the expansion header.

  18. Nova says:

    There are IC’s designed exactly for this exact application. Pushbutton interface, a momentary push asserts an interrupt signal, holding forces a power-off of the supply. It actively monitors the device and can latch off power once it signals it’s down. LTC2951 and LTC2955 are good examples.

    It’s actually a bit sad the PI has been lacking such a critical element since it’s introduction. What’s the point in small form factor and low power if you need to change the form factor in order to not pull idle power 24/7?

  19. MattS8 says:

    an alternative solution would be ,
    this allows you to switch the power of the Raspberry Pi using an infrared remote

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