The Proportional/Integral/Derivative controller or PID controller or just PID, is a proccess' control techinics that join Proportional integral and Derivative actions, thus causing the error signal is minimized by proportional action, integral action and cleared by a speed obtained with the preemptive derivative action.
It is based on mathematical modeling of the response of a loop process to be controlled.
In practice the PID controllers are found inside electronic controllers called "single-loop", often with microprocessors, and also through software on programmable logic controllers (PLC) and other control equipment.
In this project, we will simulate a brightness control with Arduino.
The Arduino will be running the PID library which can be found at: http://playground.arduino.cc/Code/PIDLibrary
In addition to the PID library for Arduino, will also need the PID Front End for processing, which is a GUI in order to configure the control parameters, such as P, I, D, Set Point and ways of working, etc. .. .; performing a user-friendly interface with Arduino.
You can also download the PID_FrontEnd from the link above.
As we will work with Arduino and Processing, we need to have the Arduino's IDE and Processing 1.0.1 2.0b8 installed in our computer.
To the Processing software, run properly with PID_FrontEnd, we also need the library "ContorlP5" for Processing installed in our computer.
You can Download the library "ControlP5" directly from the related link below: http://www.sojamo.de/libraries/controlP5/#installation
For details on PID control processes, I advise you to visiting the PID_V1 Library's creator website. http://brettbeauregard.com/blog/2011/04/improving-the-beginners-pid-introduction/
Also access the "Control Guru" website for more details about automation and control. http://www.controlguru.com/pages/table.html
Details about "Control Systems" can be found in the website: http://www.facstaff.bucknell.edu/mastascu/econtrolhtml/CourseIndex.html