基于MATLAB和usb外置声卡的信号回检，检测信号频率，幅值，功率等。-Based on MATLAB and usb external sound card signal back to check, test signal frequency, amplitude, power, etc..

STM3210B-LK1开发板玩USB的程序，包含固件、驱动和测试用的应用程序,上下位机通讯，很简单的实现。-The LK1 development board STM3210B-play USB-program, including firmware, drivers and test applications, the upper and lower machine communication, very simple to achieve。