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M1-ATX with a non-ATX computer?

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  • M1-ATX with a non-ATX computer?

    I'm using a single board computer (SBC) that simply uses a standard hard drive molex connection for power. It's not an ATX computer.

    I bought an M1-ATX psu from another forum member, and didn't even consider the fact that the M1 may not work with my SBC, and now I have a bit of a problem.

    Whenever the SBC gets power, it turns on. I was planning on having the M1 send a signal to the SBC (through one of its serial ports), and have the SBC shutdown and then have the M1 hardoff.

    Now I know that with normal ATX power supplies you can short out the green wire on the ATX connector with a black ground, and the power supply will turn on. I do not know if doing this will harm the power supply in any way.

    I also don't know a good way to do this. If I had the M1 hooked up to the battery in my car, the M1 would start powering the computer when the car's ACC line is switched on. When the car is turned off, would the M1 then send a signal to the SBC to shut down, and the hardoff after say, 45seconds. Would it still hardoff, and then power up like normal the next time I start the car?

  • #2
    I have a similar setup, in fact we may be using the same SBC. Mine's a Pegasus PC/104 SBC that came out of a hard disk tester.

    You can jumper the M1-ATX to turn on automatically. It's been a while but I believe you do it just like on a normal ATX power supply, which makes sense since the M1-ATX is supposed to work like one. I emailed the company and asked them and they said it was okay. I can double check the wiring this weekend if you want.

    For now I have a switch that kills the input power to the M1-ATX to force it off when I don't want to run it. When the switch is turned on, the M1-ATX and SBC power up a few seconds after I start the car or ACC is on. Unfortunately the SBC won't hibernate, so I need a way to initiate a shutdown when ACC drops before the M1-ATX turns off. I think I have the HARDOFF set to 45 seconds right now.

    I've been looking at the serial port shutdown software in another thread that will start a shutdown if pins 4 & 8 are shorted. I haven't tried it yet, but I plan on pulling the carpc out this weekend and starting to do some testing with it along with some other work.

    I was just going to connect ACC to a relay connected to pins 4 & 8 of the COM port, but it would be better to use J6/J8 from the M1-ATX to drive the relay. Maybe it could directly pulse the COM port but it depends on the signal.

    Zotac N630I-D-E M/B w/ Nvidia 7100, E5300 cpu, Xenarc 700IDT, M2-ATX, XP, RR & DFX 5.1.


    • #3
      I was wondering how you were going to use the COM port to sense the ignition switch. What software would sense that the 4 and 8 pins were connected?


      • #4
        There's a thread here somewhere that discusses it. Someone wrote a program to sense the COM port and it will trigger a shutdown. I believe the latest version is for sale at the mp3car store but there was still an early version in the thread that could be downloaded. I haven't had the time to try it yet.

        I think I searched for serial port shutdown or something like that. Sorry I can't find it for you right now, but if you look you'll find it.

        Zotac N630I-D-E M/B w/ Nvidia 7100, E5300 cpu, Xenarc 700IDT, M2-ATX, XP, RR & DFX 5.1.


        • #5
          As far as i know you could short the green/ground and turn the M1 on just fine.

          I think you may want to try a relay to short the green/grnd connection.
          Then use the serial to shut down the unit. The M1 should turn on just fine after the hard off

          Heres what i would do:
          Turn on:
          ACC is connected to relay and M1 Sense connection
          ACC is switched, PC powers up.

          Turn off:
          ACC is turned off
          USB Power maintains PC Power
          M1 sends signal to shut down board via serial port
          after 45sec M1 hard off

          i will attach one of my fabulous Paint diagrams in a minute as i need to perfect it so my crazy explanaition make sense
          Brown 2010


          • #6
            okay heres my fabulous paint diagram to help with my crazy explanation.
            Attached Files
            Brown 2010


            • #7
              Nice one, thanks. I'll give it a go when I get to this point in the next couple of months.

              I just got everything working and on my test drive it looks like the M1 is shutting off after a bit. I think it may be getting hot, although it's never been a problem in the past. And right before a long road trip. GRRRRR.

              Zotac N630I-D-E M/B w/ Nvidia 7100, E5300 cpu, Xenarc 700IDT, M2-ATX, XP, RR & DFX 5.1.


              • #8
                Was it on longer than normal when it got hot this time?
                It may just need better air circulation....

                good luck guys
                Brown 2010