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.

55 thoughts on “ATX Raspi Is A Smart Power Source For Raspberry Pi

    1. ATX is actually not just a PSU standard, but a set of standards that define many things in PCs like screw hole location, extension card placement or power connectors etc. This might be great but I see no similarities between this board and ATX PSU. It definitely need some new name, Maybe RTX or something.

    2. they call it atx, due to “ATXRaspi solves this problem by allowing you to have an ATX style shutdown button that will issue a shutdown signal to RaspberryPi for you.”

      but I agree, should have been called softstarter or softpower or simlar.

      1. PiTX, RaspTX, PiPo (PiPower)… Just throwing some good ones out there to chew on – Agree with the rest, awesome device, can’t wait to get my hands on one, but definitely needs a name change, regardless of the original intent/thought behind that name for the device…

        1. EXACTLY!

          without the ACPI ***_DRIVERS_*** loaded into CPU/RAM
          there IS NO SHUTDOWN BUTTON!!!!!!

          instead the chip would abruptly shut OFF power
          if HELD DOWN for 5 seconds, maybe even
          a suspend event notice if pressed momentarily,
          check your BIOS/CMOS settings…

      1. I’m not one to chime in among that group, but there’s a reason we have standards. If people deviate from standards just because “they like it better that way”, then everyone loses. I don’t see this as being a know-it-all vs. everyone else thing. I see this as a “be a professional” thing. I’ll not apologize if that doesn’t suit you. Your only actual solution is to write a new standard and convince the industry to adopt it.

    1. 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.

      1. 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.

        1. 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.

        2. 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.

    1. 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.

  1. 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

  2. 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.

    1. i power mine with a hobby ubec that i got off ebay for $3. it plugs into the power pins on the gpio header and bypasses the poly fuse entirely. and since it can deliver many times the current than the pi needs, i also power a usb hub with it (i got the first version and dont want to bypass the usb fuses). all that fits in a tiny case made out of lego.

    1. Looking at the PCB it should be possible to add the function to the IC seeing it knows its on.. it would just have to check milis() to see if the button is pressed longer than x time.. also it wouldn’t really interfere with rebooting with the GPIO reboot/shutdown

  3. 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

  4. 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.

    1. 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

    2. 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.

  5. 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?

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.