I am current running Windows 7 Home Premium and I'm using usb power on my nerdkit. I was wiring up the morse code decoder when i ran into this problem: I want to get the code on, but the nerdkit isn't appearing on the device list. What i really don't understand is that it was just appearing about 20 minutes ago when I put the blinking LED code on it. Now, Windows is showing absolutely no sign of connection. Did I really just fry my cable?

One more thing, this probably doesn't have to do with the usb cable, but before I tried getting the code on the nerdkit, I replaced the temperature sensor with a transistor. When I turned it on by plugging the usb cable in (while in programming mode), the transistor got really hot and started shooting out smoke. I replaced that transistor with another, and now its not smoking, but I'm at the problem described above. Hopefully this didn't damage the MCU, but I have no idea if this could be the source of this problem.

Hi Kareemroks101,

Why did you replace the LM34 with a transistor? What are you trying to accomplish by this?

If you were powering your circuit off your computer and you managed to make a transistor start smoking, that means that you were pulling all that current (enough to fry a transistor) from your computers USB port through your cable. This is very dangerous for both your computer and for your computers USB port. It is very likely that you fried your USB-Ser cable, or it is possible your USB port shut itself down due to the over current.

If you are not perfectly sure what you are doing I highly suggest you switch back to battery power, to electrically isolate your sensitive electronics while you are still getting the hang of things.

Try restarting your computer, the USB Port might come back after that.

Humberto