Port Access

[JohnAnderton]

I'm working on a senior project for my college which uses a computer to process video data and control a robot based on the image processing calculations. The program will be written in C++ and will output a pulse-width modulated (PWM) signal to a relay. I am familiar with microcontroller development and access through different pins, however I am unsure how to go about sending a simple signal from the laptop to the relay. It will also have to read from one switch. Only two wires are needed for the output, so I would like to be able to use a USB port but not use the USB communication protocol. Is that the best solution? If so, how do I send bits to the USB lines?

(I am using Microsoft Visual Studio 2010 on a Windows 7 32-bit machine)

Thanks for any input about my output!