4*4键盘扫描程序，本程序默认键盘总线接到P2端口，并且把P2口的低四位作为X坐标，高四位作为Y坐标。如不是用P2口做键盘总线，修改“KEYBUS”。-4* 4 keypad scanner, the program received a default keyboard bus port P2 and the P2 port four as the X coordinate of the low and high four as the Y coordinates. If it is not

IIC总线读取传感器的X,Y,Z三维加速度值，极大的方便与平衡机器人，状态保持，状态转移等设计开发。-IIC bus read sensor X, Y, Z three-dimensional acceleration value, great convenience and balancing robot, the state maintained, the state transition and other design and development.