Exercise Machine GUI © 2003. I programmed a driver .dll in C++ that established communications with a custom hardware controller, wrote a stress-test application to test it, and then interfaced it with an attractive user interface using Visual Basic. The front-end GUI was designed to be used on an excercise machine currently in the r-n-d phase. The prototype consisted of a custom circuit board attached to a huge metal chassis. The GUI had to interface with an 8-bit processor through the serial port. A protocol was designed which allowed the Windows front-end to help with the computationally expensive tasks such as spline curve editing (you can drag control points around to create a custom smooth torque curve) and hardware diagnostics.