Cypress FX2LP系列的USB 控制芯片 例如CYPRESS68013型号。 本例程实现了HID KEYBOARD的功能，通过I2C与外部数据通信。 主要处理在periph.c中的TD_POLL函数-Cypress FX2LP serial USB control chip. eg. CYPRESS68013 type。 this sample program use i2c interface to communincate with external keyboard, and

Than 8 switch outputs Port B of the PIC18F2550 is used. Power gets the circuit from the USB port. Power supply is separate from the microcontroller and the computer galvanically. switching signals USB socket intended as a virtual serial port COM4. To