Design Of A Portable Spectral Analysis Digital Storage Oscilloscope

The response to the national on innovation talents, colleges and universities are actively promoting the inside and outside of class, school and comprehensive practice teaching mode, students used to develop extracurricular innovation practice activity time ratio compared with the past has greatly improved. But the equipment conditions often restrict the practice of extra-curricular activities is more extensive, effective development. A selection of papers for electrical and electronic engineering students extracurricular practice characteristics, development of a spectrum analysis function of the portable digital storage oscilloscope, to effectively meet the electricity class specialized students in extracurricular practice needs.This paper analyzes the electricity class specialized students in extracurricular practice demand, the domestic portable device, and conducted extensive research of College Students' extracurricular practice, combined with the actual demand, research and development will be targeted in the waveform display, spectrum analysis and low cost, fill the portable waveform display device in the extracurricular practice application blank.Research on portable oscilloscope signal processing system, using SOPC technology route, building FPGA+Nios II soft core design scheme of the system, to achieve high system integration, design the power, volume and cost.System selection of Altera Cyclone FPGA ( EP1C6G240 ) as the hardware core device, to realize the system function of digital signal process. Study on FPGA combined with ADC, to achieve the time-base circuit under the control of the data acquisition and storage; and the use of Nios processor and Avlon bus technology, implementation of TFT LCD screen display control and other key technologies were discussed in detail. Study on the system front end signal processing circuit is researched, focus on the use of the relay structure, solve AC / DC switch and the signal to be measured amplitude attenuation problem. The paper introduced in detail in the Nios II integrated development environment IDE, using the SPI mode development SD card read write function; and the butterfly operation and the Hanning window treatment, achieve the function of spectrum analysis process. The thesis completed the system design and Realization in hardware and software function development, making a prototype. After the prototype hardware circuit debugging and testing, the test results meet the expected indexes.