这个接口卡程序负责采集低频音频信号，USB控制芯片采用AN2131QC。软件包括3个模块：Keil51编写芯片固件程序，vc++编写USB驱动程序和用户程序-the interface card collection procedures for low-frequency audio signals, control chips using USB Peripheral. The software includes three modules : the preparation Keil51

USB2.0频谱分析仪是一种高分辨率的动态信号谱分析系统，既可用于中低频低通信号的分析和处理（最高频率不超过20MHZ），也可用于频率很高的带通信号的分析和处理。-USB2.0 spectrum analyzer is a high-resolution dynamic signal spectrum analysis system, which can be used in low frequency communication, analysis and processing (not mo

For USB program, low pass filter for audio,Audio low-frequency Pass filter.-For USB program, low pass filter for audio, Audio low-frequency Pass filter.

High volume USB 2.0 devices will be designed using ASIC technology with embedded USB 2.0 support. For full-speed USB devices the operating frequency was low enough to allow data recovery to be handled in a vendors VHDL code, with the ASIC vendor