Design, U-disk-based Multiple Process Data Acquisition

This paper taking AT89C series microcontroller as the core, integrating modern storage technology, USB technology, Visual Basic development technology, designs a data acquisition system, which is based on U disk, Multi-channel, low-power, take-easely.The system has multi - microprocessors, the main microprocessor is responsible for reading data from U disk, writing data in it and exchanging data with the sub-microprocessor, the sub- microprocessors is responsible for collecting and processing data. The multi-microprocessors communicate through parallel port under appropriate clock control. Multi- microprocessors greatly reduce the burden on the host processor, make system consisting of functions modulars possible and increase the system's ease of debugging. In course of lab testing, take two way temperature signals' collection as examples.The main microcontroller is AT89C55WD chip, produced by ATMEL Company. USB interface chip is CH375,produced by Nanjing Qinheng electronics Co. Ltd.,The sub-microcontroller is STC12C5412AD chip, produced by Hongjing science and technology Co. Ltd., with 8-channel 10-bit A/ D being responsible for data collection built in. Temperature sensors are glass-packaged MF58 thermistor.Read and write U disk documents with the FAT32 format. Data communication software is programmed in C language. The sub-microprocessor collects two signals under set sampling intervals, strain and converse the original collected temperature data, and communicates with the main microprocessor. Develops sampling parameters (such as sample interval) choices of data and applications software modules such as reading and writing U disk in Visual Basic language. The collected Multi-channel data is written into U disk with ASCII format. The data in U disk can be analysis and processed in PC off-line. At the same time, software and hardware design have adopted effective anti-interference measures.In this paper, the whole system design, system board, debugging process and the results of experiments are descripted in detail.