I'm not sure if this is the correct place to be asking this question, but here goes. I'm trying to interface a device that will use one sensor and control one actuator. The actuator I think will be analog from 0 - 5V and I'm not sure on what sensor I'm going to use yet. At any rate, I would like to connect this device to a computer eventually, and my preference is USB...as its a growing standard. I downloaded the spec for USB 2.0 and saw that two signals D+ and D- are used to send or recieve signals...but I don't know how I can change the voltage level or record from the sensor using these two signals? If anyone has done something similar, or can provide some insight...that would be greatly appreciated.