Study And Design Of Portable Digital Storage Oscilloscope

Oscilloscope is an important tool in debugging of the circuit. With the development of science and technology, an oscilloscope has become a kind of intelligent instrument with functions: parameter measure, detecting analyze, waveform display, storage. Digital storage oscilloscopes, one of oscilloscopes, are widely used in many testing domains, as the representative of intelligent testing instrument. However, the traditional digital oscilloscope is largely inconvenience in testing, due to its heavy mass, big volume and high cost, so a portable digital storage oscilloscope gradually developed. Currently, foreign portable digital oscilloscopes hold the dominant position in the market, however, it is relative later in domestic, and most for low-end products, and expensive in the market, which is unfavorable for their widespread application of production test. In this paper, based on the working principle of digital storage oscilloscopes, a design method of portable digital storage oscilloscope is proposed based on ARM and FPGA. This kind of portable digital storage oscilloscopes completely replacing traditional digital storage oscilloscopes, with low-cost, is greatly conducive to wide application in production and experiments.The ARM is used as the core in this paper. The FPGA is used as the data acquisition and preprocessing module, it complete the input signal acquisition and transmission. The ARM drivers the LCD display with external SSD1963chip, the SSD1963chip caches the input data, so as realize the control effect of the acquisition and display. The ARM peripheral FLASH completed the storage of program code, character and saving the waveform data, and other functions. External power supplies and built-in lithium battery can freely switch system power supply mode. This paper completed the ARM and FPGA circuit, power supply module, signal acquisition module, FLASH data storage, LCD liquid crystal display module circuit design.Secondly, this paper writes oscilloscope’s software system with transplanting FatFs file system and writing the GUI graphical display system. It realizes the results of oscilloscope’s test displayed on the LCD screen in real time. According to the use of the oscilloscope site requirements, the software system was divided into five function modules such as "basic function","trigger menu","menu","waveform storage","waveform playback" and so on. Each function module is independent, the software system‘s structure is clear, convenient for user operation, and improves the human-computer interaction.The experimental results show that the oscilloscope with input signal dynamic, low cost advantages, fully meet the demand of all kinds of field testing and outdoor testing.