main.c

C语言的KEY4X4的矩阵键盘,已经调试成功.可以很便移植,是本人自己写的.

//IO说明：P3 数码管 ， P4 按键4x4
//注意 ：时钟对程序扫描的影响很大 


#include <MSP430x22x4.h>
#define uchar unsigned char
#define uint  unsigned int
#define led   BIT7
const uchar  segment[16]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xf8,
                            0x80,0x90,0x88,0x83,0xc6,0xa1,0x86,0x8e};
uchar static key_flag=0;
uchar static  count=0;
uchar key1;

void int_clk()
{

}
delay()
{
   uint i;
  for(i=0;i<=1000;i++)
       ;
}

 
display(uchar data)     //数码管显示键值
{
  P3OUT=segment[data];
} 
//扫描一行根据参数line决定扫描具体那一行
uchar scan_key(uchar line)
{
  uchar key; 
  P4OUT=line;  
  switch (P4IN&0Xf0)
 {
  case 0xe0:key=1+line;break;
  case 0xd0:key=2+line;break;
  case 0xb0:key=3+line;break;
  case 0x70:key=4+line;break;
  default:key=0xff;break;
 }
 return(key);
}
void fast_scan()
{
  uchar temp; 
  P4OUT&=0XF0;//低位全部为0，判断有无键按下  
  temp=P4IN&0xf0;
  if(temp==0xf0)key_flag=0;
  else          
  {
   key_flag=1; //如果有键按下者标志为1，否则为0
  } 
}
void over()
{
  uchar temp;
  P4OUT&=0XF0;//低位全部为0，判断有无键按下
  do
  {
    temp=P4IN&0xf0;
    if(temp==0xf0)break;  //等待键盘弹起
  } 
  while(1);
 
}
//读取键值
uchar get_key()
{
  uchar key;
  
  while(1)
  {
    key=scan_key(0xe);
    if(key!=0xff){key|=0x80;P4OUT=0X0f; break;}

    key=scan_key(0xd);
    if(key!=0xff){key|=0x40;P4OUT=0X0f;break;}
 
    key=scan_key(0xb);
    if(key!=0xff){key|=0x20;P4OUT=0X0f;break;}
  
    key=scan_key(0x7);
    if(key!=0xff){key|=0x20;P4OUT=0X0f;break;}
  }
  switch(key)
  {
     case 0x8f:key=12;break;
     case 0x90:key=13;break;
     case 0x91:key=14;break;
     case 0x92:key=15;break;
     case 0x4E:key=8;break;
     case 0x4F:key=9;break;
     case 0x50:key=10;break;
     case 0x51:key=11;break;
     case 0x2C:key=4;break;
     case 0x2D:key=5;break;
     case 0x2E:key=6;break;
     case 0x2F:key=7;break;
     case 0x28:key=0;break;
     case 0x29:key=1;break;
     case 0x2A:key=2;break;
     case 0x2B:key=3;break;    
     default:key=0xff;break;
  }
  _NOP();
  return(key);
}
delay2()          //注意此处的延时对显示的稳定性影响很大
{
uint i=0,j=0;
 for(i=0;i<=200;i++)
{
  for(j=0;j<=100;j++)
        ;
      }
}
int main( void )
{  
 WDTCTL=WDTPW+WDTHOLD;//关闭看门狗
 int_clk(); //初始化时钟
 P4DIR|=BIT0+BIT1+BIT2+BIT3;//键盘初始化
 P3DIR=0XFF;
 
 display(0);  
 while(1)
 {  
   fast_scan();
   if(key_flag==0) continue;//判断是否有键按下，如果是者消抖，否退出本次扫描
   key_flag=0;
   delay2();
   fast_scan();  
   if(key_flag==1)
   { 
    key_flag=0;
    key1=get_key();
    over(); 
    delay2();
    display(key1);
   }
 } 
  
}