智能车学习（七）——按键矩阵的实现

一、原理说明

就是按键矩阵代码书写的一个说明，就是讲K5到K7先输出高电平，而K1和K4则调成上拉输入，如果检测到K1到K4有一个变为0，说明有按键按下去，立刻进行转换，是的K1到K4设置为输出高电平，然后读取K5到K7为上拉输入，然后再读取到为0的点，通过这两个数据就能确定按下了那个按键。

二、基于KVL25代码书写：

1、头文件

#ifndef __KEYSQUARE_H
#define __KEYSQUARE_H

/***********宏定义************/

#define keySquare_K1 PTD7
#define keySquare_K2 PTD6
#define keySquare_K3 PTD5
#define keySquare_K4 PTD4
#define keySquare_K5 PTD3
#define keySquare_K6 PTD2
#define keySquare_K7 PTD1

#define Keynum1 1
#define Keynum2 2
#define Keynum3 3
#define Keynum4 4
#define Keynum5 5
#define Keynum6 6
#define Keynum7 7
#define Keynum8 8
#define Keynum9 9
#define Keynum10 10
#define Keynum11 11
#define Keynum12 12
/*****************************/

/***********函数神经***********/

int keyBoard_get(void);

/*****************************/

#endif

2、源文件

#include "include.h"
#include "common.h"
#include "OLED.h"
#include "gpio.h"
#include "KeySquare.h"
#include "lptmr.h"

int keyBoard_get(void)
{
   unsigned char tempdata=0x00;
   unsigned char bdata=0x00;
   int keyNum=0;

   //设置为输入，用于检测
   gpio_init (keySquare_K1, GPI , 1);
   gpio_init (keySquare_K2, GPI , 1);
   gpio_init (keySquare_K3, GPI , 1);
   gpio_init (keySquare_K4, GPI , 1);

   //设置为上拉
   port_init_NoALT(keySquare_K1,PULLUP );
   port_init_NoALT(keySquare_K2,PULLUP );
   port_init_NoALT(keySquare_K3,PULLUP );
   port_init_NoALT(keySquare_K4,PULLUP );

   //设置为输出
   gpio_init (keySquare_K5,GPO , 0);
   gpio_init (keySquare_K6,GPO , 0);
   gpio_init (keySquare_K7,GPO , 0);  

   lptmr_delay_us(4);
   tempdata  = gpio_get(keySquare_K1);
   tempdata += gpio_get(keySquare_K2) << 1;
   tempdata += gpio_get(keySquare_K3) << 2;
   tempdata += gpio_get(keySquare_K4) << 3;
   if(tempdata != 0xff)
    {
       bdata = (tempdata << 4) | 0x00;

       gpio_init (keySquare_K1, GPO , 0);
       gpio_init (keySquare_K2, GPO , 0);
       gpio_init (keySquare_K3, GPO , 0);
       gpio_init (keySquare_K4, GPO , 0);

       gpio_init (keySquare_K5,GPI , 1);
       gpio_init (keySquare_K6,GPI , 1);
       gpio_init (keySquare_K7,GPI , 1);

       //上拉
       port_init_NoALT(keySquare_K5,PULLUP);
       port_init_NoALT(keySquare_K6,PULLUP);
       port_init_NoALT(keySquare_K7,PULLUP);

       lptmr_delay_us(4);

       tempdata =  gpio_get(keySquare_K5);
       tempdata += gpio_get(keySquare_K6) << 1;
       tempdata += gpio_get(keySquare_K7) << 2;
       bdata    += tempdata;
       switch(bdata)
       {
           case 230:  keyNum=Keynum1;    break;
           case 214:  keyNum=Keynum2;    break;
           case 182:  keyNum=Keynum3;    break;
           case 118:  keyNum=Keynum4;    break;
           case 229:  keyNum=Keynum5;    break;
           case 213:  keyNum=Keynum6;    break;
           case 181:  keyNum=Keynum7;    break;
           case 117:  keyNum=Keynum8;    break;
           case 227:  keyNum=Keynum9;    break;
           case 211:  keyNum=Keynum10;   break;
           case 179:  keyNum=Keynum11;   break;
           case 115:  keyNum=Keynum12;   break;
           default:     break;
       }
    } 

   return keyNum; 

}

三、使用说明

使用的时候，在Main函数进行调用，每次会返回一个值，0表示没有按下去，否则就返回对应的按键值。