This enables ARduino boards to connect to 802.11b/g wireless networks with Roving Networks RN-131C module. It uses the SC16IS750 SPI-to-UART chip to free up the Arduino s UART.

xrm117x spi 转uart驱动代码，可以将spi 物理接口扩展出两个uart 接口-xrm117x spi transfer to uart driver code，it can extend uart number in your project！！

基于WK串口扩展芯片实现，SPI接口转4个UART的驱动程序-Based WK serial port expansion chip, SPI Interface to 4 UART driver