Nebula Pi 开发板评测报告（十二）——红外通信功能测试

#ifndef _INFRARED_H
#define _INFRARED_H

#include "reg52.h"

#define Time_16ms 16000 //16ms

extern bit Flag;                        //定义一个接收标志，正确接收后标志置1
extern unsigned long infvalue;  //接收数据存放变量，32位
extern unsigned char *keys;
unsigned int Time(bit Flag);

void Int1_Init(void);
void KeyTrans(unsigned int keyvalue);
void KeyValue_Transform(unsigned char k);


#endif

#include "infrared.h"

sbit inf = P3^3;        //位定义红外接收引脚
bit Flag;                       //定义一个接收标志，正确接收后标志置1
unsigned char *keys;


void Int1_Init(void)
{
    TMOD &= 0xF0;   //清空定时器0的控制位
    TMOD = 0x01;    //定时器0工作在方式1，16位定时器
    
    TR0 = 0;            //关闭定时器
    ET0 = 0;            //关闭定时器0中断，采用查询模式
    
    IT1 = 1;    //设置外部中断1下降沿触发
    EX1 = 1;
    EA = 1;
    
    inf = 1;    //初始化红外接收引脚为高电平
}

unsigned int Time(bit Flag)     //输出低电平直接输出时间，高电平需要判断是否超过16ms
{
    TH0 = 0;
    TL0 = 0;        //定时器初始值清零
    TR0 = 1;        //开启定时器
    
    while( (inf == Flag) )          //P3.3引脚的高电平时间超过16ms时为超时
    {
        if( TH0 >= (Time_16ms >> 8) ) break;
    }
    TR0 = 0;
    return (TH0*256 + TL0);         //返回定时时间，单位为us  
}

//键值转换函数，将键值转换成按键字符
void KeyValue_Transform(unsigned char k)
{
    switch( k )
            {
                case 69:keys = "CH-";break;
                case 70:keys = "CH";break;
                case 71:keys = "CH+";break;
                case 68:keys = "PREV";break;
                case 64:keys = "NEXT";break;
                case 67:keys = "PLAY/PAUSE";break;
                case  7:keys = "-";break;
                case 21 :keys = "+";break;
                case  9:keys = "EQ";break;
                case 22:keys = "0";break;
                case 25:keys = "100+";break;
                case 13:keys = "200+";break;
                case 12:keys = "1";break;
                case 24:keys = "2";break;
                case 94:keys = "3";break;
                case  8:keys = "4";break;
                case 28:keys = "5";break;
                case 90:keys = "6";break;
                case 66:keys = "7";break;
                case 82:keys = "8";break;
                case 74:keys = "9";break;
                default: keys = "error";    break;
            }
}

#include "reg52.h"  
#include "LCD1602.h"  
#include "infrared.h"  
  
unsigned char key;  
  
unsigned long infvalue; //接收数据存放变量，32位  
  
  
void main(void)  
{  
    LCD_Init();             //LCD初始化  
    Int1_Init();            //红外初始化  
    LCD_WriteString(1,1,"Infrared Key:");  
    while(1)  
    {  
        if( Flag )  
        {  
            Flag = 0;               //接受标志清零  
              
            key = ( unsigned char ) ( infvalue >>16 );    //取出数据码  
  
            KeyValue_Transform(key);    //键值转换
            LCD_WriteString(2,1,"        ");  
            LCD_WriteString(2,1,keys);      //在第二行第一个位置开始显示  
        }  
    }  
}  
  
  
void Int1() interrupt 2  
{  
    unsigned int i;  
    unsigned int TL,TH;  
      
    TL = Time(0);  
    TH = Time(1);  
    /****下面语句判断引导码的正确与否****/  
    if( TL < 8000 || TL > 10000 || TH < 3500 || TH > 5000 )     //高、低电平的时间超过范围的话直接退出  
    {  
        IE1 = 0;  
        return;  
    }  
    /****引导码正确后进入数据的接收****/  
    for(i=0;i<32;i++)  
    {  
        TL = Time(0);  
        TH = Time(1);       //接收0或者1的数据，然后进行时间的判断  
        if( TL < 300 || TL > 700 || TH < 300 || TH > 1800 )     //高、低电平的时间超过范围的话直接退出  
        {  
            IE1 = 0;  
            return;  
        }  
        infvalue >>= 1;   //先接收最低位，因此先右移一位再接收  
        if( TH > 1300 )  //高电平时间大于1300us认为接收的为逻辑1  
        {  
            infvalue |= 0x80000000;             //接收为1时高位置1，否则仍然为0  
        }  
        Flag = 1;  
          
        IE1 = 0;          
    }  
      
}