Quote Originally Posted by Tissy
With this previous suggestion, this will be only to detect whether or not the device is plugged in or not. As with this device it will always be plugged into a USB port, whether the machine is powered on or not. If the PC is off, 5v will still be on the USB ports to keep this device powered up as usual.

Hope this makes sense. Any other suggestion?

Steve
Not sure if this is for a commercial application, but stealing power from the USB bus without a properly enumerated device being attached is a blatant violation of the official USB spec...

To do this properly, you'd want either (a) the device to be enumerated and active at all times or (b) receive power from a source external to the USB bus.

John