USB 3.0 (Device Descriptor Request Failed)

I had trouble getting started with my RexQualis UNO. I installed the IDE, then connected the power cord to my board and then plugged my board into the USB 3.0 port on my computer.

I got a USB error. The IDE didn't recognize my board. I tried and tried to reinstall the drivers, but nothing worked.

As I was going to give up for the night, I was taking my installation apart. I first unplugged the power cord from my board. When I did this, the LEDs remained lit up. The board was getting it's power from the USB cord. So I went back in to the IDE and now my board is recognized as COM: 3.

Everything works. So if you are having this problem, try hooking your board up to your computer without plugging the power into your board. Let the USB power up your board.

Good luck.

Use USB2.0.

Using USB as power source is what people normally do at first. That said, it really is supposed to work when plugged into USB and on external power... (not that it's unheardof for people to report that it doesn't work...)

What voltage were you supplying it with?

USB 2.0 does often work when USB 3.0 will not (many implementations of USB 3.0 do a halfassed job of backwards compatibility), but in this case, I doubt it's the problem at hand.

I'm using the power supply that came with the board. It is 9V - 1A. My laptop only has USB 3.0. I read about people using older multi-port USB extensions that would work. I have one somewhere but I couldn't find it.

Another thing to be aware of with USB 3.0 (and USB 2.0 to a lesser degree) is power management.

Laptops are the worst as they are often configured OOB to take full advantage of sleep modes and low power options.