The controller is undertsting phase. Success has been accomplished in send values to a display terminal. In our case this will be the boost pressure. The next step will be to used the onboard a/D converter to measure pressure from a three bar map sensor. The measure pressure will then be displayed on the terminal.

The Three Bar Map Sensor. This sensor should read approximatey 1.65 volts at at mospheric pressure. Sending this Pressure to the terminal should show a value around 1351.

3 BAR map sensors all share a common pinout, although the connector keying may be different: Pin A -- Ground Pin B -- Sensor output Pin C -- +5 volts

Apparently to implementt any form of control mechanism is pretty complicated. It almost like rocket science. These are are called PID controllers. Proportional,Integral Derivative controllers. This type of controller avoids ringing. Ringing occurs when the pressure for example oscillates about the set pressure. An error signal which is the difference between the set pressure and that actual pressure is used to bring the system back tothe set pressure.

The error used to feed to the control system is multiplied by gain.The Intergal part is the sum of the errors over given time intervals. This gives the history of the error. Once the controller know the history of the error it can can predict what to do to bring the system near the set point. The derivative function show the future state of the system. Whether it is increasing or decreasing. This is done by comparing current error with previous error. These additional controls can bring the system to its set point in half the time of a system without these features.

A good example of PID controller is the inverted vertical pedulum. A mass attached to the end of a rod is balanced by a microcontrolled motor system. This is somewhat like balancing a stick with your thumb. When the stick falls to one side you move your hand to compensate. In the case of the controller the base is driving left or right to keep the pedulum vertical.