AS PER THE REQUEST OF THE ARDUINO TEAM, THE ARDUINO PID LIBRARY HAS BEEN MOVED TO GIT-HUB ( https://github.com/br3ttb/Arduino-PID-Library ) THESE FILES HAVE BEEN LEFT HERE FOR REFERENCE PURPOSES ONLY, AND ARE NOT TO BE CONSIDERED USABLE

PID Controllers are found everywhere in industry, controlling all sorts of things: Temperature, Level, and Flow, among others. The reason they're so prevalent is because they're simple and effective.

There has been a Barebones PID algorithm available for the Arduino for some time now. The goal of this library was to create a more modular pid controller on-par with those found in industry. All of the standard industrial error checks are in there. The main improvements that this Library brings are:

• Speed of implementation. you still have to tune it, but the coding/debugging piece is easier.

• The ability to change tunings on the fly (i.e. while in Auto)

• The Addition of output limits

• Being a Library, multiple PIDs can be easily created within the same program

• The option of putting the controller in Manual (turning it off / reinitializing it)

• Reset-Windup mitigation (the previously published Arduino PID addressed this somewhat. This library does it in a more comprehensive way)

Documentation can be found at http://www.arduino.cc/playground/Code/PIDLibrary