低频交流信号测量系统 采用12864屏幕实时显示交流信号波形，并测量Vpp和频率-Low frequency AC signal measurement system 12864 screen real-time display of AC signal waveform, and measuring the Vpp and frequency

基于LM3S9B92开发板AD模块实现交流小信号有效值的测量并能同时测量频率-RMS measurement of AC small signal and capable of simultaneously measuring the frequency based the LM3S9B92 boards AD module