dc-dc power supply. they have a startup/shutdown controller built in.
So i was curious, and wondering about the boot processs and shutdown process with a CarPC. Well for example its not good to just shut a computer down without the proper shutdown..So how do you go about having the CarPC shut down correctly, even though the power is cut from it when you turn off the car? Secondly, whats the most efficiant way to have your carPC boot? Fastest and most convienent?
My OLD 2001 Mitsubishi Eclipse GT:
"The Project That Never Ended, until it did"
next project? subaru brz
If this is a laptop, then you'd probably want something like the carnetix. No need for the ebay'd car power adapter. This can then hibernate, sleep, or shutdown the unit (and of course start-up) via the usb connection once wired up, and set up properly(wake on usb needs to be set in bios). You will of course still need the proper power connector for your particular laptop to solder with the right polarity to the carnetix's 19v output(once set via jumpers).
See the extended information tab on this page here for videos and further specs and howto's for this particular unit.
The usual method is ACPI via the power button pins on the motherboard (usually mini-itx anymore) used for the carpc application from an automotive DC-DC power supply such as the M2-atx, or in my case an OPUS 360. So long as the polarity on the pins are observed(ACPI proper pin is marked as Pwr button + usually, and any of the others on that motherboard header section marked as ground will do for -), the unit will get it's turn-on and shut-down signals from the automotive power supply the same as if you pressed the button on your desktop. Usually, and in my own case, a momentary switch(NO, normally open) is wired in parallel to this to manually trigger this when needed, same again as the power button on a desktop, or laptop should something funky happen, or futzin' around with something causes it to hang on shut-down. Hope for the best, plan for the worst as the saying goes. It's not needed often, but it is needed on occasion, and sometimes I just don't wish it to power up for a quick trip, a simple tap of the button...done.
All of which usually give you many choices as to how and when it will turn on, and shut-off, including just putting it in standby mode, or hibernation, or fully off. Hard cutting power is not what happens. At least not if thought out and executed correctly.
The fastest and most convenient method is using standby mode of course. This keeps the 5v rail powered as everything is stored to RAM, so depending on how much is being kept powered, this can be a considerable battery drain issue.
Many, including myself have quite a laundry list of usb devices connected, in addition to the RAM, so I opted to just have my own straight shut-down and turn-on. Resuming from hibernation(RAM saved to file) is most times pointless IMO if you use 2gigs or more of RAM, doublely so with an SSD. It might be up by like half a second faster with hibernation rather than straight booting with mine.
I have a remote line turning on all related peripherals, including the audio amplifier, so everything stays on and shuts off with the OPUS PSU. This PSU is set with jumpers to stay on for 10minutes after the ACC(accessory) line is turned off. So with my mustang, as soon as I turn off the car and open a door the timer starts(car has a delayed accessory timer of it's own). This gives me time to get my coffee, make a convenience store run, or pump gas and not have to go through startup/shutdown. As well as letting me just leave the ACC line powered with the key the same as if I had a stock head-unit still. Albeit with a far shorter window of running without the engine going in my case.