Metal Detection System Based On Cortex-M3

In modern society, with the development of people living standards, people pay more and more attention on their own life safety, especially food, medicines and so on. Maybe there is a lot of hidden danger in these fields. So, it is essential for the products to detect the metal impurities in the factory. Accordingly, various kinds of metal detection system for drugs and food appeared.As metal detection equipment, the metal detection system detects metal through the electric, magnetic, and other physical principles. It collects and manages the detection signal, and then removes the contaminated products. At present, the market of the metal detection system is occupied by foreign products. The imitation of the domestic products is serious. Therefore the study of metal detection system has broad market prospects and certain social value.The metal detection system was designed in this article. The main core was STM32F103ZET6which was based on the metal core ARM Cortex-M3from STMicroelectronics. The functionality of the system can be achieved, such as, sending the single drug out, sending drug into the detector head through the transmitting unit, removing the contaminated drug, and collecting the good drug.In this article, detailed analysis and design of metal detection systems for drugs was given out. It was designed from the four aspects of the mechanical structure, the detection head, hardware and software. In the mechanical structure part, the design of them was given, such as a new type of drug sending apparatus, the transmission apparatus and the automatic removing apparatus. The principle of detector head was analyzed. The coaxial coil mode was selected through comparing of multiple design options. The sinusoidal oscillation circuit schematic was also given out. In the hardware part, starting from STM32, the schematic of power and minimum system peripheral circuit is given out. And DC motors, DC motor drives, servos, current sensor are all selected. So did the typical circuit. In the software part, the function and parameters of main control chip was introduced. The main program flow chart was given out. And the functions include DC motor drive and control, servo control, detection signal acquisition, analog-to-digital conversion and so on.Finally, aimed at the achieving metal detection system, the article summarized the physical prototype and design process. It put forward those needs to be improved or strengthened, the development direction of the metal detection system and the outlook on the future development.