Along with technical progress, the development of the small and intelligent PID control is becoming more and more important. MCUs with 8-bit CPU, cannot afford large quantity of data processing, especifically with the demand of real time，multi-task. While MCUs, with 32-bit CPU and the high performance-price ratio and outstanding performance, is becoming the first choice for electronic products recently.
Embedded PID controller's hardware system design is detailed introduced in this thesis. The signaltranslation electric circuit is used in this hardware system to transform the signal to another which can recognized by processor or the external devices, through the touchscreen. we can carries on the man-machine interaction, simultaneously display the real-time data and obtain the setup parameter. ARM processor S3C2410 is also used to enforce PID calculation and demonstrate kinds of man-machine contact surface. The data, which can be used in the PID computation and the system, must be obtained from the external device though the underlying devices drviers. So it is necessary to develop device driver for the hardware. This article detailed introducts the electric current voltage switching circuit、voltage electric current switching circuit and lowpass filter . Also the AD driver, the PWM driver and the touchscreen driver programming process is introduced in detail.
Keywords: Digital PID, Embedded Linux Systems, Linux Device Drivers , Signal convertion
