Turn on PC with USB-device

Question

I want to be able to turn my PC on and off using an IR-remote sensor that is connected via USB to the PC. The sensor is a custom PCB implemented with an AVR microprocessor and V-USB software USB-implementation.

Now, turning off the PC is no problem with software, but is there any way to turn ON the PC using USB?

(Please note, I'm not talking about booting from USB-stick or USB-power supply ...)

Solution 1

There seem to be two problems:

1. keeping the USB powered on while the PC is off. It seems that most mainboard have a jumper for this functionality.

2. bringing the PC back to life. There seems to be no standard functionality for this. The solution is to "press" the PCs power button through the AVR on the USB board. I know, this means extra cable from the USB to the PC, but it seems to be the easiest solution.

Another workaround could be to send the power-on signal to the PC over ethernet. But I guess this will be more complicated than the power button solution and it involves extra cables too.

Solution 2

This Microsoft knowledgebase article describes how to enable "wake on USB" for a USB mouse. I just checked, and my keyboard device entry (on Windows Vista) has the same choice, already checked.

So, if your AVR is emulating a USB keyboard or mouse, it should be possible to wake the computer by sending the proper data.

Solution 3

there must be a way to do this with USB, since some PCs can be switched on with the keyboard. I think this will be some looking whether your mainboard/BIOS support it (it may be you need to turn it on in BIOS, this will probably also ensure your device gets power from USB although the PC is switched off), and whether that V-USB (unknown to me) can send the "wakeup"-signal.

good luck !

Comments

[Jonatan]

Keeping the USB device powered is no problem (a BIOS setting on my mainboard). I will go for a solution like yours, adding a transistor in parallell with the start button.

[Paul]

A relay might be cheaper than a transistor rated at the power you need... unless all you need is a control line that attaches to relays or power switching within the power supply.

[rdmueller]

it's only the start button, not the power switch. so a transistor should work.