DIY High-Speed Book Scanner from Trash and Cheap Cameras

Step 59 Handle/Electronics: Hub 2.

Open it up. We are going to cut off the USB connector, but we need to determine which pin is positive and which is ground. The easiest way to do this is to plug it into your computer and use a multimeter to see which pin has +5V on it. In this case, +5V turned out to be the leftmost wire -- the red wire -- and ground was the brown, rightmost wire. This is probably pretty consistent between hubs, but you should test yours anyway.