Data Processing And Data Communications Of The Laser Gas Analyzer Based On FPGA

In order to improve the laser gas analyzer, the thesis selected AD7862in the AD sample piece, which was high-speed, low power, dual-core12-bit ADC, and processed the converted digital signai by the industry median average filteringprocessing to make the value of the measured gas concentrations more accurate. After processing data in the microcontroller, the thesis proposed serial communication between MCU and PC to make laser gas analyzer network.According to the AD7862principle of work and the work succession, the thesis designs this controller in the ISE software with the Verilog language. The design uses the way of the limited state machine, and then builds its test platform in the ISE software. The thesis judgments design controller is whether reasonable or not through droving of the test vector. According to the position value average filter method, the thesis designs this filter in the ISE software with the VHDL language. The design uses the way of the assembly line, and then builds its test platform in the ISE software. The thesis judgments design filter is whether reasonable or not through droving of the test vector. Serial communications between PC and AT89C51has been achieved by proteus software, and the next bit machine AT89C51was replaced with simulation circuit designed of proteus, using pure software to complete the communication. PC software has been achieved by Serial debugging assistant SComAssistant V2.1, and SCM software has been achieved by assembly language.ISE comes with ModelSim simulates the AD7862controller, and the simulation map is in full compliance with the requirements of the chip conversion. The filter module also uses ModelSim simulation. Simulation diagram and the filtering method are stable together, and it applys to any gas concentration data. In front two separated modules have been designed and simulated. When they communication between SCM and PC, the microcontroller transmits data to the PC and displays data in a virtual terminal. The PC transmits data to the microcontroller and also displays data in a virtual terminal, and back to the PC. The paper has analyzed the practical application of the two communicate with each other in the gas analyzers. Finally, the thesis has presented to compensate for atmospheric pressure of gas concentrations in the test results by a model with least square method.Through three aspect improvements, the laser gas analyzer can determine the more accurate gas density value, in order to take a better measure to protect our survival environment.