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Power up PC (SageTV) with a COM(x) dongle idea.

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blueroomelectronics

Well-Known Member
I've been playing with DVR software (SageTV) and although it supports wakeup from suspend it got me thinking about a simple PIC device that runs from a 3V coin cell with a 32768Hz crystal RTCC and a simple software serial port (slow baud rate for sure)
Most motherboards still have an internal COM header and you can have power up by modem ring.
So with a simple command string from the PC it could set the time it wishes to power on, set the clock, everyday alarm (like the bios has)
I've got a home server that automatically wakes up via the BIOS alarm. A DVR requires a more flexable solution.
Of course it's all moot if I could find software that let's you set the motherboards internal alarm from within XP.
 

Sceadwian

Banned
I've used SageTV, BeyondTV, and the DVR software that came with my Hauppauge card. They all have nice fluff interfaces for it, but all it does is create Windows scheduler events. My last XP machine would wake up for recording from any of the three softwares, as well as schedualed defrags.
 
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Sceadwian

Banned
No. But if you're in standby the machine is not shutdown. If there is a power failure you can set the bios up to automatically power the machine back up depending on your bios. I'm not sure how windows would react to scheduled events passing before the scheduling process starts, but I think it can. Not to useful for TV recording.

You'd need a DAMN good reason to need to turn a machine off from a 'powered off' state on schedual to want to do such a project, can't think of any reasons myself, if you have one though go for it, wouldn't be too hard, the power button on a PC is nothing more than a basic logic switch nowdays, VERY easy to interface to a 5V external logic.
 
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blueroomelectronics

Well-Known Member
I'll have to toss the Watt meter on the PC when it's in standby (yep the fans still spin on the CPU). The machine could power on a couple of minutes before and Sage is set to autorun.
 

Sceadwian

Banned
From shutdown to standby with compatible hardware not going to amount to much.
 

Sceadwian

Banned
I TRY to only post when I know what I'm talking about, I know, it's grab bag with me.
 

Sceadwian

Banned
I did say I try, never said I succeeded. I fail at least.... 50% of the time. Anything past 50% is just a best guess. But I do try to keep it lively, again that's at best 50-50
 

LiquidKernel

New Member
The simplest way to do this, which lots of carpc PSUs use, is to just use an NPN transistor to bring the motherboard's power bottom pin low.

You can hook it up in parallel with a switch, so you can still retain the ability to use it.
 

Sceadwian

Banned
I didn't like the prices, I haven't tried Sage or Beyond recently. If I need TV on my PC I use Windows Media Center in Vista, don't need the other features and my tuner is crap anyways so it'd be a waste. My experience with BeyondTV trials were completely flawless. SageTV experience was so short I don't remember it. It didn't floor me like BeyondTV did at the time, mind you this was like 5 years ago.
 

mpep

New Member
I agree with LiquidKernel. The power switch control is usually required to be pulled low. Therefore a NPN transistor being driven is all that is required. Yes it does mean hacking the hardware, but oh well. Only you will know.:D
 
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