利用SPI控制数码管显示,SPI接收按键执行响应操作-Control digital control using SPI, SPI implementation of response actions to receive keys

cc3200 spi_demo实现串口通信读取cc3200sd卡的功能，为下一步wifi通信做准备(Cc3200 spi_demo realize serial communication, read cc3200sd card function, for the next step WiFi communication preparation)

使用SPI总线读取芯片数据，和芯片进行通讯(Use the SPI bus to read the chip data and communicate with the chip)