Design And Development Of WDXRF Main Control Board Using LPC1766

The sequential wavelength dispersive X-ray fluorescence spectrometer is a highly complex and large scientific instrument. As the main means of elemental analysis, it has been widely used in many fields such as archaeology, geology, metallurgy, petroleum, chemical engineering, biological, medical treatment, environmental protection and so on. And the market demand is increasing year by year. However, it all depends on import currently in our country, and huge capital flows overseas, so the domestic independent research and development are imperative. The main control board is a key part of the sequential wavelength dispersive X ray fluorescence spectrometer. In this thesis, the WDXRF main control board is designed and developed based on LPC1766 microprocessor. And it has great application value in the control system.Firstly, according to the system control requirement of the instrument, a control scheme of the sequential wavelength dispersive X ray fluorescence spectrometry is developed by using LPC1766. This scheme is composed of three parts, including the motion control system, the AD/DA data acquisition and processing system and the upper and lower computer communication system. Motion control system can control the selection of key moving parts in the instrument. AD/DA data acquisition and processing system can achieve the function of data signal acquisition and control. And the communication between PC and WDXRF can be realized by the upper and lower computer communication system.Secondly, the specific implementation of the hardware and software of the control system is introduced in detail. Based on LPC1766 microprocessor, the motor of the motion system is controlled by making full use of the rich GPIO port and powerful PWM module with the photoelectric switch, and the data are collected and processed with the configuration of the external AD7606 and DAC8831 conversion chip, and the communication between the upper and lower computer is realized by setting the UART module with RS485 chip.Finally, the main control board is debugged and tested, and the rationality and feasibility of the design are verified. The test results are in accordance with the requirements of the JJG 810-1993 wavelength dispersive X-ray fluorescence spectrometer verification regulations. The main control board can control the instrument to complete the qualitative and quantitative analysis of all elements from Be to U successfully, and have high performance price ratio.