利用定时器触发ADC采集语音信号，存储到FLASH中，读回后用SPWM输出，经过低通滤波后可以还原出原始信号波形，效果还不错-Use a timer to trigger the ADC capture the voice signal stored in the FLASH, read back with SPWM output after low-pass filtering can restore the original signal waveform, the results were