Design Of FIR Linear Phase Digital Filter Based On Microcontroler

The information of weather, hydrologic was needed while making a decision of economic development programming or some idiographic project. All the above data is helpful for analysis only if it is collected through long time. It is needs a huge manpower and material resources to obtain these valuable and enormous data. The constitution of the system of non-man watching, long-distance control, auto-measure is needed.Under the development of the computer and the network technology, establishing a distribution hydrologic measure system of long-distance control become possible. However, during the measurement of water level, it is always contaminated by any stochastic disturbance signal caused by passing ships or flurry, all these disturbance signal should be filter. In the digital signal processing field, FIR filter has been used widely in speech process, image process, communication systems, measure systems, etc. Microcontroller is one of the key automatic system of industry, which has been used widely in the collection of information, auto-control, smart-instruments, etc.In the thesis, we have designed a filter system based on MCU using the technology of the digital signal processing. The target of filter is to remove the disturbance signal from the measure data. The method of the realization of linear phase FIR filter by AVR series MCU is discussed in detail. We have finished the design of filter algorithm, display of LED, series communication of UART, A/D transform, low power. At the same time, the low-pass filter is realized by means of the simulator and the developed board. At the last, the thesis gives the simulation result of software and hardware. Digital filter in MCU prove to be feasible and it can meet the needs of middle sampling frequency field. The whole system proves to be simple, low cost, easy extensibility.