DSATX and Standby

**HyperZulu** · 06-13-2007, 03:09 AM

So, I've done a lot of searching for an answer, but either my answer is unanswered or more likely I missed it in confusion.

What I am doing right now to do what I want is to put a a pulse switch on the MB power pins to put the system in standby and bring it out. I turn it on when I get in my car and turn it off when I leave.

First problem is that while this works, I would like the DSATX to do all this. So the first thing is I know this is possible by programming the DSATX to use VTURNON = 1 and set LOWVOLTS. One of my problems is that if I set LOWVOLTS, then that turns the PSU off completely (no standby). So, that's not the way it should work because LOWVOLTS should be the voltage at which the battery is in danger of discharging (so turn it off).

So, how do I get the DSATX to automatically shut down when I shut the car off and still have LOWVOLTS set to something like 1050?

Secondly I notice that the 5v rail is still partially on during standby. Brainstem shows 3v or something when PC is in standby. The usb sound card looks like it's trying to turn on repeatedly... it clicks like every ten seconds through the speakers. And if I pull the USB extension (which disconnects the sound card) from the computer while it's in standby, the 5v rail stops drawing power.

I have everything powered off the DSATX. There's a USB hub powered off the 5v rail which has a keyboard, touch screen and usb sound card on it. The touch screen and sound card are powered off the 12v and 5v rails respectively. All of this is connected to the computer with an active USB extension cord. That's basically how it is.

I've gone through hardware management, tried checking "allow windows to shut this device down to save power" on every USB root and such and it still does the same thing. I use devcon to disable the usb sound card before I go into standby mode. I don't know if I need to do a 'devcon remove' but seeing as how that takes forever to reload, I may as well use hibernate instead.

If I turn the computer off or go into hibernate, I don't have this problem. So, it partly seems like a Windows issue, but also I thought that the DSATX would cut power to the 5v rail anyway, but it's obviously drawing a lot of power in standby if the brainstem shows 3v on the rail.

Any ideas? Sorry for the long post.

**DarquePervert** · 06-13-2007, 04:39 AM

1 - The DSATX simplys a pulse to trigger startup/shutdown. If you set the PC's powere button to send the PC into standby, then the DSATX will trigger this. LOWVOLTS is designed to shut off the PC (hard shut off) if the voltage output from the battery is below the threshhold. It doesn't simulate a press of the power button. This is more of a battery protection feature than a convenience feature.

2 - There is a variable that you can set that will turn off 5v completely. It's too early in the morning to look it up.

However, you won't be able to maintain standby, as the PC needs the power draw to maintain standby state.

**HyperZulu** · 06-13-2007, 09:25 AM

1 - I understand how it works and it would work great except for the fact that the power supply won't send a second pulse for off/standby(in my case) unless I have LOWVOLTS set to something like 12.8V (meaning the car is off). If I use VTURNON=1 and LOWVOLTS=1050 then I turn on the car (PC starts up fine)... turn the car off... it keeps humming along unless the DSATX sees less than LOWVOLTS and then does a hard boot off. Is this how it's supposed to be or should it turn on after VINHIGHTHRESH and turn off when below VINHIGHTHRESH?... and then kill power after battery is below LOWVOLTS?

I'm unsure about how this works and it's possible that my yellow top battery is just not playing nice with everything because it holds a ridiculous charge after the car has been on for a while, so the 1300 default may not even trigger for a while. So, I'm just wondering what would trigger the "off pulse" from the power supply? LOWVOLTS or simply just when the battery is below VINHIGHTHRESH?

2 - ENABLE5VSBOFF... this is be default set to 0001(true) so the power supply should be turning off the 5v rail anyway. I've had it set to true and false with no change in behavior. So, I've left it at the default of true and have continued using standby mode. Now, I'm not sure if standby mode is being kept alive simply because of this side effect, but whatever...

This thread suggests I need the previous setting and ENABLESLEEP to false:
DSATX feature request

I haven't had any problems maintaining standby mode with them on though. I just don't like how the 5v rail is using way more power than it needs to if I have my USB peripherals connected to the PC during standby. It shows 3v running through the 5v rail if usb attached and 0-1v if usb not attached. Seems kind of sketchy.

**HyperZulu** · 06-14-2007, 04:33 PM

Maybe my motherboard is powering USB devices with the 5v rail rather than the 5vSB rail when in standby mode?

Anyone else have ideas? I'll dig around in BIOS to see if I find anything. But if anyone can think of something, holla back or something.