Aim of the book: To show the ability of proportional integral (PI) and proportional integral derivative (PID) controllers to compensate many practical industrial processes has led to their wide acceptance in industrial applications. The requirement to choose either two or three controller parameters is perhaps most easily done using tuning rules. In the present industrial fields, auto-tuning algorithm software packages are widely used and successfully applied with the aid of computers. This is showing the design and the development process of the handheld controller for PID Auto-tuning system. It describes on the software and hardware development of the handheld controller with reference to the hardware features.