[Resource Download] The download address is as follows:
https://docs.qq.com/doc/DTlRSd01BZXNpRUxl
Function description and design principle:
First, a microphone (microphone pickup sensor) is used to collect the audio signal. The audio signal is too small, which is not conducive to the direct acquisition of the single-chip ADC. Therefore, the audio signal is amplified by the LM358 amplifier circuit and sent to the single-chip ADC port for collection.
The collected audio signal is quantized and Fourier transform is used to obtain the frequency spectrum distribution of the AD value in the audio signal, and the frequency spectrum distribution array in each segment of real time is displayed on the OLED screen in the form of dots. You can intuitively experience the spectrum display obtained by Fourier FFT analysis.
Hardware system composition = STM32F103C8T6 + microphone microphone + LM358 audio amplifier circuit + 0.96 inch OLED screen + buttons.
Information description:
The STM32 program is written in C language, compiled by Keil5 software, and the file is the project source code.
The circuit diagram is an AD format schematic diagram PCB project file, which is opened with altiumDesigner.
Tips:
This design has been verified in kind. The source files and source programs of the circuit diagram are successfully verified and usable. It can be said that it is a good material for learning the design and production of MCU! Hope this sharing is helpful to everyone!
