键盘扫描函数HD7279,#define HD7279_RESET 0xa4 //复位 #define HD7279_TEST 0xbf //测试 #define HD7279_RLC 0xa3 //循环左移 #define HD7279_RRC 0xa2 //循环右移 #define HD7279_RL 0xa1 //左移 #define HD7279_RR 0xa0 //右移 #define HD7279_DECODE0 0x80 //译码方式0 #define HD7279_DECODE1 0xc8 //译码方式1 #defi