直接频率合成器 (DDS)ad9954 单点频功能程序，利用单片机控制ad9954,通过串口设置不同频率字，即可设置不同的频率。-Direct frequency synthesizer (DDS) ad9954 single frequency function procedures, the use of single-chip control ad9954, set a different frequency of the word through the serial port, you can set a different frequency.