说明：  IAR环境下，MSP430通用的无需上拉电阻4*4矩阵键盘驱动程序，IO口修改十分方便，延时函数调整到适合自己的检测效果就行。
(IAR environment, MSP430 versatile no pull-up resistor 4* 4 matrix keyboard driver, IO port is very convenient to modify, delay function to adjust to suit their own test results on the line.)