MSP430 矩阵键盘 if函数问题

2019-08-06 14:09发布

我写的矩阵键盘的程序有个问题
int KeyProcess()
{
  int nRes = 0;;

  //判断S1~S4
  P1OUT = 0xe0;
  if (m10IN == 0)       我按下了这个对应按键，我一步一步仿真到这边了，这条语句也执行了为真
nRes = 1;          然后就执行了这条语句，这条语句执行完之后我发现  监视里面  nRes  是个无效的值压根没有赋值，  最后nRes 的值是到最后没有按键按下的时候通过  else  赋值为0。请叫各位大神这是个什么情况（我先没有用中断做）

//下面是程序全部类容

#include "io430.h"
#define led20 P2OUT_bit.P0
#define led21 P2OUT_bit.P1
#define led22 P2OUT_bit.P2
#define m10IN P1IN_bit.P0
#define m11IN P1IN_bit.P1
#define m12IN P1IN_bit.P2
#define m13IN P1IN_bit.P3
#define m14OUT P1OUT_bit.P4
#define m15OUT P1OUT_bit.P5
#define m16OUT P1OUT_bit.P6
#define m17OUT P1OUT_bit.P7

void Delay(void)
{
  unsigned int i;
  for(i=0;i<100;i++);

}

void Display(int i)
{
  int j;
  for(j=i;j>0;j--)
  {
led20 = 0;
led21 = 0;
led22 = 0;
Delay();
Delay();
led20 = 1;
led21 = 1;
led22 = 1;
Delay();
Delay();
  }
  return;
}

/******************************************
端口初始化
*******************************************/
void int_port()
{
  P1SEL = 0;  //将P1设置成IO口功能
  P1DIR = 0x00;
  P1DIR = 0xf0;  //将P1.0 1.1 1.2 1.3 设置成输入IO,将1.4 1.5 1.6 1.7设置成输出方向
  P1OUT = 0x00;

  P2SEL = 0;
  P2DIR = 0x07;
  P2OUT = 0x07;
  return ;

}

/******************************************
键盘扫描程序
*******************************************/
int KeyScan()
{
  int nRes = 0;
  P1OUT = 0x00;
  for(;;)
  {
//读取各个管脚的状态
if(m10IN == 0 || m11IN == 0 || m12IN == 0 || m13IN == 0)//检测是否有按键按下
{
   break;

}
  }

  Delay();

  if(m10IN == 0 || m11IN == 0 || m12IN == 0 || m13IN == 0)//检测是否有按键按下
{

   nRes = KeyProcess();

}
  else return -1;

  return nRes;
}

/******************************************
键盘分析程序
*******************************************/
int KeyProcess()
{
  int nRes = 0;;

  //判断S1~S4
  P1OUT = 0xe0;
  if (m10IN == 0)
nRes = 1;
  if (m11IN == 0)
nRes = 2;
  if (m12IN == 0)
nRes = 3;
  if (m13IN == 0)
nRes = 4;

  //判断S5~S8
P1OUT = 0xd0;
  if (m10IN == 0)
nRes = 5;
  if (m11IN == 0)
nRes = 6;
  if (m12IN == 0)
nRes = 7;
  if (m13IN == 0)
nRes = 8;

  //判断S9~S12
  P1OUT = 0xb0;
  if (m10IN == 0)
nRes = 9;
  if (m11IN == 0)
nRes = 10;
  if (m12IN == 0)
nRes = 11;
  if (m13IN == 0)
nRes = 12;

  //判断S13~S16
P1OUT = 0x70;
  if (m10IN == 0)
nRes = 13;
  if (m11IN == 0)
nRes = 14;
  if (m12IN == 0)
nRes = 15;
  if (m13IN == 0)
nRes = 16;
  else nRes = 0;
  P1OUT = 0x00;


  //按键释放
  for(;;)
  {
   if (m10IN == 1 && m11IN == 1 && m12IN == 1 && m13IN == 1)
   {
   break;
   }

  }

Display(nRes);
return nRes;


}

int main( void )
{
  WDTCTL = WDTPW + WDTHOLD;
  BCSCTL1 = 0x47;  //最高时钟
  BCSCTL2 = 0x80;
  int_port();
  while(1)
  {
KeyScan();
  }
}

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5条回答

lujiangyuan

1楼-- · 2019-08-06 18:36

受字数限制，我删掉了函数的声明，和一些注释

yirongfu

2楼-- · 2019-08-06 19:54

  //判断S13~S16
P1OUT = 0x70;
  if (m10IN == 0)
nRes = 13;
  if (m11IN == 0)
nRes = 14;
  if (m12IN == 0)
nRes = 15;
  if (m13IN == 0)
nRes = 16;
  else nRes = 0;
  P1OUT = 0x00;

红 {MOD}部分有误吧，你的代码是顺序执行的，这样只要m13IN不等于0，就都会把nRes赋值为0。