System Of Ⅴ-Ⅰ Data Collecting For Capacitive Screen Based On FPGA

With the popularity of phones and other multimedia devices,people’s life occurred great changes,most multimedia equipment screen is the capacitive touch screen. In this thesis, based on touch screen manufacturers of industrial grade online measurement requirements, to screen capacitor detection whether good product design of capacitive current and voltage signal sampling and processing system, the final screen capacitance voltage and current data.With the rapid development of FPGA technology, the advantages of FPGA in signal acquisition has become even more prominent. A new type of FPGA generally are integrated DSP module, and FPGA in the parallel signal processing excellent performance, the realization of FPGA signal acquisition system based on fully possible.This thesis studies the design of the three systems:First, FPGA gates any point on the matrix which has 256*256 aisles through a combination of FPGA and multi-channel analog switches.Second, the section of acquisition and processing includes the signal acquisition module and the filtration module and the algorithm processing module. The signal acquisition module controls A/D converter to convert the analog signal that output from the points of matrix into a digital signal. After that, the module put the collected data into the FIFO buffer. The filtration module filters the data of the FIFO by using the smoothing filtration and put the data into the RAM of the FPGA. Third, the design makes MCU write and read special registers and RAM of the FPGA by using the agreement of MCU.The completion of each part of the hardware and software design of the system, and analyses the whole simulation. The simulation results show that the design of capacitive screen at any point in the current voltage data of digital collection, storage and processing, can meet the touch screen manufacturers online measurement application requirements, and has good application value.