基于MSP432的信号失真度测量仪设计

Design of signal distortion measurement instrument based on MSP432

针对常用的信号失真度测试仪设计复杂成本较高的问题,该文采用TI公司的MSP432单片机配合简单的外围电路设计了高集成度低成本的信号失真度测试仪,仪器利用单片机内部集成的高精度模数转换模块对信号进行采样后,通过快速傅里叶变换得到基波和各谐波分量,进一步计算出非线性失真系数并通过串口显示屏和手机APP实时显示。经测试,装置的测量信号在100~600 mV,1~100 kHz的输入信号范围内,THD测量的相对误差小于2%,实现了低成本高精度的信号失真度测量。

With the purpose of reducing the design complexity and design and manufacturing cost of the signal distortion tester of common signal measuring instruments,this paper proposes a high-integration and low-cost signal distortion tester scheme using TI’s MSP432 microcontroller and simple peripheral circuits,the scheme first uses the high-precision analog-to-digital conversion module integrated in the microcontroller to sample the signal,then obtains the fundamental wave and each harmonic component through Fast Fourier Transform,and finally further calculates the nonlinear distortion coefficient and displays it through the serial port real-time display on screen and mobile APP.After testing,the designed instrument has the relative error of THD measurement less than 2%within the input signal range of 100~600 mV and 1~100 kHz,which realizes the low-cost and high-precision measurement of signal distortion.