This driver was developed using a USB keyboard from Cherry,as indicated by the VID and PID codes. These IDs must be set for the device you intend to support. Similarly, you will need to set Class to the appropriate string for your device class.
PID calculations for the _pid structure *a. This function uses the positional form of the pid equation, and incorporates an integral windup prevention algorithim. Rectangular integration is used, so this function must be repeated on a consistent time basis for accurate control.