the prob with that is the associated voltage drop with the optoisolator or led say a led has a voltage drop of 1.5v (i dont know what a usual value is) then the 5v line of the usb will only be @ 3.5V because you have a big voltage drop theres also the fact that u limit the current with a resistor so that would probably stop lotsa stuff from working
Just use a comparator if you don't want a mechanical solution. If you're ok with the possibility of it wearing out or whatever - just use a microswitch.
You could do it by modding the USB socket. Cut the ground pin in half, so it is two separate parts that are electicly isolated. One part will still be connected to the system ground, so the USB device will be grounded. The other part will be used as the ground connection for your LED. When you insert a USB plug, it bridges the two parts of the ground pin, effectivly grounding the LED and making it turn on. As the LED would be connected in parallel with the USB device (probably directly to the 5V supply), there would be no voltage drop on the USB 5V line. Here is a bad diagram: ------------ USB plug GND pin ----- ----- USB socket GND pin LED USB GND GND Another way to do this would be if the USB socket case is also grounded, but not connected to the ground pin inside the socket. Either that, or just adjust the 5V regulation circuit to give 5V + the drop over the LED MoJo
It's been done already Here's a tutorial I found eariler when looking for some other xbox mod stuff. edit my link didn't work right so im trying again link /edit
Re: It's been done already It only works because the controller ports on the XBox have an extra 5V, to detect when the pad it plugged in and provide power for rumble packs etc. MoJo
I've seen that a long time ago already, that's why I revived the topic in the first place. It only works on the xbox because there is an extra yellow wire that is only used by light guns and possibly steering wheels. So that is connected to ground inside the controller and then the ground of the LED is connected to that yellow wire so it lights when you plug it in. The problem was that I was already using that wire for an on/off switch in the controller. Someone already found a way around it though, which is using the shielding of the controller port.
