On 9/14/07, <b class="gmail_sendername">David Brodbeck</b> <<a href="mailto:gull@gull.us">gull@gull.us</a>> wrote:<div><span class="gmail_quote"></span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div style=""><br><div><span class="q"></span><div>Just brainstorming here -- If your laptop has a "wake on ring" feature in its BIOS, you might be able to interface that device to the serial port and avoid opening up the machine. I think you'd just have to pull the RI (ring indicator) pin high. This is pin 9 on a DB-9 serial port. Note that RS-232 uses negative voltages to indicate a logic 1, so that means applying -3 to -12 volts. You could probably test it with a 9-volt battery before spending any money on hardware.
</div><div><br></div></div></div></blockquote></div><br>David,<br><br>I have been working on a solution for my desktop that doesn't seem to wake on USB events, even though it is supposed to, so I was testing the wake on ring feature myself. I was able to trigger a wakeup by applying +5v from one of the 5vsb pins on the motherboard, so it might not be necessary to come up with a negative voltage. Considering I was testing with a voltmeter probe as a jumper, it might just as easily have been the "disconnecting" of the +5v that did it as opposed to the "connecting", but does it matter which edge of a pulse? Not in my book ;-)
<br><br>I'd give that a whirl before I tried to come up with a negative voltage solution. It can be done, but why complicate things if you can get a voltage source from the laptop's ports (like a USB port with standby power?) ready-made for use to trigger the WOR.
<br><br>Craig.<br>