| Data acquisition and processing system is widely used in data monitoring and analysis,As the modern major signal processing technology,DSP play a key role In data acquisition and processing system,This paper selects the high performance DSP chip,it makes the system has the function of collect data and real-time processing,The introduction of USB interface improves the data throughput between the data acquisition system and PC, eliminates the bottleneck.This thesis is aimed at issue"detect the grain diameter of phytoplankton under the water and measure the density of the phytoplankton"to design the part of data acquisition and real-time processing,we mainly need to collect the fluorescent signal and doppler signal,because of the phytoplankton under the water doesnot show up regularly , the emerging of both signals are unpredictable. The DSP program can detect the pretrigger of two channels'data, When the data exceed setting threshold value,the system will continue to collect the following signals,So we can get the whole envelope curve of both signals.This thesis mainly discusses the design of a data acquisition and real-time processing system with maximum acquisition rate at 5M,analysis the function of each part and implementation method.The overall design thought is : signal after sensor into analog electrical signal, using ADC to convert the analog signal into digital signal, with the control of CPLD,the data is collected into DSP and then became FFT, the data after Process should through the USB interface to PC and display real-time spectrum. In terms of hardware design,the thesis Specific introduces the Sensor module, analog conversion module, signal processing module, the logical module, the power modules,communication module and PCB design.In terms of software design,the thesis expounds on the design and development process ofDSP algorithm procedures ,based on USB2.0 protocol the thesis introduces the firmware of interface chip and the software design of PC. |
PDF Full Text Request