这是一个音频信号发生器，信号频率可以调节，适用于ios系统，用XCode，OBjective-C语言开发。

基于LabView的信号发生程序，能调节波形和频率等-The signal based on LabView program can adjust the waveform and frequency

通过调节载波频率可使外差法产生的差频在零频率点附近变动，从而使得双稳系统的输出信号发生特征极为明显的变化，为频率检测提供可靠的检测依据。(By adjusting the carrier frequency, the difference frequency produced by the heterodyne can be changed near the zero frequency point, which makes the output signal of the bistable s