基于S3C44B0X的小车控制程序，通过不同的按键结构

代码说明：

基于s3c44b0x的小车控制程序，通过按键扫描判断不同方向指令，进而发出相应的PWM波驱动电机以及控制电机转动方向的I/O信号，采用中断实现换挡调速-Based on the car S3C44B0X control procedures, through the different buttons to scan to determine the direction of instruction, and then issue the corresponding wave PWM motor drive and control the direction of motor rotation of I/O signals, the use of interrupted realize Shift Speed