| Food security, which relates the quality of live and the international trade friction caused by it is becoming more and more frequent, is paid great attention by each county and regarded as public safety of nation. It is extremely important to sustainably improve and develop detection methods and technology and strengthen supervision to food security. Therefore, the development of an instrument, which can detect pesticide residue quickly and accurately, is of vital social and economic significance.Combined with development status of food security detector and development trend of embedded system, we adopted CPU based on ARMTDMI-S to develop the food security detector to meet the requirement to run embedded operating system. According to design requirements, the principle of the hardware design has been studied and a scheme is offered in this thesis. Module construction design makes the function extension of the detector easier. We make an intensive study of display interface circuit and design a configurable LCD controller, which notably improves the speed of graph display.Linux is ported to the detector, which shortens the cycle of development a great much and improves system stability. Comparing with other embedded graphics systems, MiniGUI has many advantages such as scalability, light-weight and low resources consumption, high performance and high reliability, and configurability. On that basis, basic graphics generation algorithms in computer graphics have been studied and new line generation algorithm and new circle generation algorithm, which replace the counterparts in MiniGUI, are presented in this thesis. The experimental results show that new Bresenham's circle generation algorithm averagely improves 11.05% in efficiency in the generation of circular arc in first quadrant and 7.68% in entire circle generation. MiniGUI-based graphical user interface offers a friendly human-computer interface and make operations easier and intuitively. |
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