I just took over a project for a person that left the company. The project was supposed to be fully documented, but the documentation seems to have come up missing. The application involves using a microcontroller as a PID controller. I will have a desired speed, and the actual speed. I will get an error signal by subtracting the actual speed from the desired speed. One of my colleagues says that the PID controller will just integrate, differentiate, and multiply the error signal and I should get what I want. I want to get a pulse width modulation factor so I will know how long I should run the device to lower my speed until the next sample.