The Design And Implementation Of Embedded Digital Oscilloscope

As great progresses have been seen in the development of integrated circuit and modern digital signal processing technology,digital oscilloscope has become a kind of intelligent measuring instrument capable of displaying,measuring,calculating,analyzing,recording and other features and has gradually replaced traditional analog oscilloscope.In order to solve the key technical problems in designing digital oscilloscope system,many domestic and well-known foreign oscilloscope manufacturers and experts have proposed various methods and have made many breakthroughs.Dedicated digital oscilloscope highlights itself with excellent digital signal processing abilities,as well as FPGA being parallel and their smooth working mechanism,which made them the core of modern oscilloscopes.However,DSP and FPGA in the digital oscilloscope system focus on the algorithm of processing discrete signals,as the result,the sampling of input analog signals and the multitask scheduling had become their weaknesses,and these increased the complexity of the peripheral circuit designing and software programming.With the development of ARM technology,the microprocessor have integrated the DSP instruction and the floating point arithmetic units which made them prominent in digital signal processing.Also,their flexibility and rich peripheral resources are also superior to those of DSP and FPGA’s.In this paper,in order to reduce both the cost and technical difficulties of digital oscilloscope,and to improve the real-time performance of spectrum analysis and ameliorate the human-computer interaction ability.STM32 microprocessor was used as the control core,combined with external signal processing unit to design the embedded digital oscilloscope system.The paper proposes timer control methods of A/D sampling,used the system timer PWM output mode as the trigger source of A/D sampling part,and the use of DMA technology to deliver the sampled value.With all parts above we made an embedded digital oscilloscope system with timer control A/D sampling,DMA data delivery,window function processing,FFT algorithm analysis and waveform information display.In this paper,the μC/OS-II operating system is transplanted in the embedded digital oscilloscope system to implement multitask scheduling so that the stability of the system can be improved,the μC/GUI is transplanted to design the man-machine interface and grant it with a good appearance.