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P1900 <> PC power sync

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  • P1900 <> PC power sync

    In my previous carpc setup I had a different PSU which had a problem:

    1. Ignition ON > PC startup
    2. After 5 seconds Ignition OFF > PSU waits 30s and fires "power signal" to the PC.
    3. If the PC was still in the startup procedure (after forementioned 30s), it didn't shutdown. Ever.
    4. Running PC, with ignition OFF > very bad!

    How's this handled in P1900 unit? I saw "startup" and "shutdown" lockout in the manual. Does this mean if I turned the ignition OFF while in "startup lockout" mode, the carpc would stay ON fornever?

  • #2
    I could be wrong as it was a while ago that I read the manual.. but I would guess that the lockout period just prevents the shut down signal being sent while it is still starting up. Once that timer has run out it should send the signal if any of the other shut down conditions are now met. IE the car is now turned off or worst case when the voltage drops below the low voltage threshold.
    But I would need to read the manual again to check:


    • #3
      Thank you for your input on the matter.

      I understand what "lockout period" is for. The problem is whether the "ignition OFF" signal is ignored completely and is not fired after the "lockout period".
      The question is: can P1900 detect that the ignition is OFF after the "lockout period"? Or does the PC keep running until the car battery gets below 10.6V or something.

      I checked the manual and support site, but the answer eludes me.


      • #4
        You are right the documentation is not really clear on that aspect.. I would hope it does as I would suspect that once past the startup lockout it goes into the run state and immediately starts monitoring the acc line which would be dead leading to a shut down..
        When mine arrives I will try to test this for you.


        • #5
          The P1900 constantly monitors the AUX/Stereo power signal (taken from the stereo plug, yellow?). If you start the car, then after it sends the signal to turn on the PC (5secs) you decide to turn off the car, the PC has a minute to turn on(lockout period). Then the P1900 detects that the AUX/Stereo signal isn't there and sends the shutdown signal to the PC, initiating another lockout period.
          After that lockout period it will depend on how you have the P1900 configured. I initially had mine set to give a constant signal to maintain standby, but found that after a weekend of not driving I'd have a drained battery as it wouldn't properly switch to hibernation. Now I've got it to completely turn off after the turn-off lockout period, standby is now maintained by the laptop battery rather than the car.

          Hopefully this helps out a bit more.
          03 Hyundai Elantra GT {Worklog}
          HP TC4400; 250GB SATA, WiFi, BT, 12.1" touch
          RideRunner; w/, OBDMPG, mediaart, RRMedia, DFXVoice and more...
          cmdRR tall skin creator

          86 Pontiac Fiero SE 2m6
          possible carpc install


          • #6
            To clarify: when ignition is turned OFF while in "lockout period", the shutdown/hibernate signal will still be transferred after the lockout. (p1900 monitors the +12v from the ignition ...).
            Yea, it seems only logical, but the problem is that m2 and a few other so called "car PSUs" aren't that smart and the PC-CAR sync gets reversed easily. Carpc stays ON and shuts down only after the battery was almost completely drained. Luckily tha p1900 goes a step further. yay.