Analog leakage control system based on embedded Linux
                                                           XIONG Sichang, MAO Guobin, TANG Haoran
（The Ministry of Education Key Lab of Mechanical Manufacture & Automation,Zhejiang University of Technology, Hangzhou 310014, China）

Abstract: Aiming at calibrating the detection accuracy of gas leak detection equipment, the traditional calibration platform has the problem of complicated process, large measurement error and poor portability, the principle of simulation leakage was studied and analyzed, and the relationship between simulated leakage rate and speed of stepper motor was established, a kind of leakage control system simulation based on embedded Linux was designed. The hardware circuit of the system was designed around the function of the system, and the control program and manmachine interaction interface based on the development environment of Linux+Qt was designed. Through the pulse width modulation on the TOUT0 port of S3C2440, the stepper motor speed was controlled accurately, and used the external interrupt EINT0 of S3C2440 count the number of pulse from photoelectric encoder accurately, realtime obtained the measured simulation leakage rate, and its error and stability were analyzed. The experimental results show that the system meets the requirements of simulation leakage accuracy and stability when calibrating gas leak detection equipment, and provides a convenient and reliable calibration platform for gas leak detection equipment.

Key words: stepper motor; embedded Linux + Qt; pulse width modulation; simulation leak