用于地铁系统闸机剪式门的开关控制程序，内有原理图及PCB、源代码。-Switch control program for scissor doors of the subway system gates, schematic and PCB, the source code.

USB雷达——看牛人如何架设自己的导弹防御系统（附电路图&PCB、雷达+导弹程序、纯雷达程序）-USB radar-- see expert how to set up its own missile defense system ( with circuit diagram &PCB, radar missile program, pure+ radar program )

AT91SAM9G20开发板原理图和PCB, 该开发板可运行LINUX程序，网口，串口，SPI和USB扩展接口-AT91SAM9G20 development board schematics and PCB, the board can run LINUX program, network port, serial port, SPI and USB expansion interface