一个多通道ADC转换DMA传输数据。程序是选择的通道0和通道1，各采集50次，然后滤波取其平均值，并发送到串口显示采样的电压值。-A multi-channel ADC conversion DMA transfer data. Program is selected channels 0 and 1, each collecting 50 times, then filtering the mean value, and sent to the serial display sampled v