Research Of Modular Synthesis Digital Instruments

Automatic Test System(ATS) is used fornational economy and national defenseconstruction widely, has become the necessary ensure of the electronic devicesefficient reliable operation, and developmental level of will direct influence qualityandproduction life safety. However, the existing testing equipment have two-sideddefects: First, the systematic have only one function, unable to complete thenecessaries of detection of modern highly integrated product; Second, most of inprocess of apply of system based on PXI and VXI bus high production costs and havebig volume, those shortcomings cause equipment unable to widely used. So, one kindof carry convenient and multifunctional and low cost integrated test system is urgentneeded to meet the needs of complex testing tasks.The idea of modularized schemewas put forwardin this thesis, which have thecharacteristic of international dimensions and expansibility, users can make free withfunctional modules to complete test assignments, user will feel very facility. Thesystem contains master module and constant current source module and TFT_LCDmodule. There are two microprocessors in the master module, they organiccombination make use with the parallel bus, if the event needthe two microprocessorscommon to work the parallel will play a part. Master module leave rich externalinterface,40P cable is used for connect users can connect functional modules.Constant current ia gained from voltage converter, the current output range is0.00~24.00mA, user use STM32change the output current. TFT_LCD module useshigh-performance A/D display controller chip RA8875, LCD screen selectionEVTFT4.3to build a touch-interactive interfacewhich have the advantage oflow-power and high-resolution. Next, this paper design software systems of thedigitized instrument, transplanted μC/OS-II operating system in STM32is successfully,this can make the system can deal with many tasks real-time. This paper put into use ofFatFs file, for LCD module real-time display test results laid the foundation. Digitizedinstrument need finish many jobs, the software system divide into "module identification","current generation","LCD Driver","System Status Settings","Software System Information", thesoftware structure is legible, which offer facilitiesto user.The modular design is feasible through the proving of experiments, theexpandability of is outstanding. Experiments showed that: the parallel bus of this papermeet communications among modules and the requirement of data transmissionbetween modules. By applying the STM8microcontroller solved module identificationproblem; through experimental data to verify the accuracy of the constant currentsource is less than0.5μA and achieve the real-time monitoring to D3V3and D2V5voltage; TFT_LCD modules has advantages of high resolution ratio, which havelowerconsumption and higher reaction speed, these advantage make human-computerinterfacewidely used. The modular synthesis digital instruments has advantages ofportable, concentrated feature andthe cost ratio is high, user just about need suchsystem,the system not only make safe operation but also raise effciency.