msp430矩阵式按钮驱动程序

#include "msp430x14x.h"unsigned char LineScan[4]={0xef,0xdf,0xbf,0x7f}; //列值列举void ADD(){  P4OUT+=1;}void SUB(){  P4OUT-=1;}unsigned int key_check(void)  //检测是否有按键按下{ unsigned char temp;       P1DIR=0xf0;                  //定义P1.4~P1.7为输出 temp=P1IN & 0x0f;           if(temp!=0x0f)   return 1; else   return 0;} unsigned char scan_key(void)   //扫描对应按键的键号{P1DIR=0xf0;unsigned  char count;unsigned char i,temp,m,n;    //m为列的值,n为行的值unsigned int flag=0;for(i=0;i<4;i++)               //列扫描{  P1OUT=LineScan[i];             //获取扫描的列  temp=P1IN&0x0f;    if(temp==0x07)                //为第一行     {n=0;                       //记录按下按钮的行      flag=1;                    //标志检测出来      break;}   else if(temp==0x0b)           //为第二行     {n=1;      flag=1;      break;}   else if(temp==0x0d)           //为第三行     {n=2;      flag=1;      break;}   else if(temp==0x0e)           //为第四行     {n=3;      flag=1;      break;}} if(flag==1)  {m=i;  flag=0;  count=n*4+m;     switch(count)       {         case 0: {;break;}         case 1: {;break;}         case 2: {;break;}         case 3: {;break;}         case 4: {;break;}         case 5: {;break;}         case 6: {;break;}         case 7: {;break;}         case 8: {;break;}         case 9: {;break;}         case 10:{;break;}         case 11:{SUB();break;}         case 12:{;break;}         case 13:{;break;}         case 14:{;break;}         case 15:{ADD();break;}       }     return;    } else   return;}void Delay(char wDelay)  //延时子程序{  while(wDelay!=0)    wDelay--;}int main( void ){  WDTCTL = WDTPW + WDTHOLD;  P4DIR =0xff;  P4OUT=0X00;  while(1)  {   if(key_check())   {Delay(10000);      if(key_check())       {        scan_key();        while(key_check());        P1OUT=0x0f;      }   }  }}