Design of simple oscilloscope and spectrum analysis system

To design a simple voltage signal analysis system and realize waveform measurement and spectrum analysis on voltage signals inputted, adopt STC12C5A60S2 single-chip microcomputer (SCM) as core processor and, in combination with waveform shaping circuit, realize the function of period measurement on voltage signals measured, and then have the measured voltage signals transformed into digital signals using the 10-digit high-speed analog-digital converter provided within the single-chip microcomputer itself, followed by the storage of digital signals, thus finally realizing the functions of oscilloscope in combination with the function of period measurement. Realize the function of spectrum analysis on the measured voltage signals by FFT algorithm, and realize the function of display using LCD (liquid crystal display). The test reveals that for the oscilloscope, its frequency measurement scope is 1Hz ~ 5KHz, amplitude measurement scope is 0V~5V, the largest periodic error and amplitude error are respectively 12us and 19mV, and what shown in the frequency analysis chart of sine wave and square wave is basically consistent with corresponding theory.