#include <REGX52.H>
#include "intrins.h" //_nop_();延时函数用
#define uchar unsigned char
#define uint unsigned int
sbit SO = P3^6; //P3.6口与SO相连
sbit SCK = P3^4; //P3.4口与SCK相连
sbit CS = P3^5; //P3.5口与CS相连
sbit wx = P2^6;
sbit dx = P2^7;
const unsigned char DevID = 1; //本机设备ID
unsigned char buffer; //串口接收缓冲区
unsigned char rcv_buffer[20];
unsigned char send_buffer[20];
unsigned char flag_ok = 0; //接收完毕的标识
unsigned int MAX6675_Temp;
unsigned char Flag_connect;
unsigned char CRCH,CRCL;
unsigned char wd[2]; //wd[]：BCD码的温度
unsigned char flag_dis; //显示刷新的标识
unsigned char dis[4] = { 0x00, 0x00, 0x00,0x00 };
unsigned char code SMG[] = {0xc0, 0xf9, 0xa4, 0xb0, 0x99, 0x92, 0x82, 0xf8, 0x80, 0x90, 0x88, 0x83, 0xc6, 0xa1, 0x86, 0x8e};
unsigned int MAX6675_ReadReg(void)
{
unsigned char i;
unsigned int dat;
i = 0;
dat = 0;
CS = 0;
SCK = 0;
for(i=0; i<16; i++) //get D15-D0 from 6675
{
SCK = 1;
dat = dat<<1;
if( SO==1 )
dat = dat|0x01;
SCK = 0;
}
CS = 1;
return dat;
}
/*
* 功 能：延时，若干毫秒
* 参 数：毫秒数
* 返回值：无
*/
void DelayMs(unsigned int i) //一个延时函数，这个函数在11.0592M晶振下的延时时间大概为1ms
{
unsigned int j,k;
for(j=i; j>0; j--)
for(k=114; k>0; k--);
}
/*
* 功 能：数码管在指定的位置显示指定的字符
* 参 数：place:要显示的位置，num:要显示的字符
* 返回值：无
*/
void SMG_DisChar(unsigned char place, unsigned char num)
{
unsigned char i;
i = 0x80 >> place; //根据显示位置选择相应的数码管
P0 = SMG[num]; //发送要显示的段码
dx = 1;
dx = 0;
P0 = i; //发送要显示的位码,只显示一位数字
wx = 1;
wx = 0;
DelayMs(1);
}
void Display(unsigned int temp)
{
if(Flag_connect==0) //Flag_connect为0 表示热电偶已连接，这时显示温度
{
if(temp > 999)
{
SMG_DisChar(3,temp/1000);
}
if(temp > 99)
{
SMG_DisChar(2,(temp00)/100);
}
if(temp > 9)
{
SMG_DisChar(1,(temp/10));
}
SMG_DisChar(0,temp);
}
else //Flag_connect为1表示 热电偶未连接，这时显示FFFF
{
SMG_DisChar(3, 0x0F);
SMG_DisChar(2, 0x0F);
SMG_DisChar(1, 0x0F);
SMG_DisChar(0, 0x0F);
}
}
void main(void)
{
unsigned char cnt = 11;
unsigned int t;
while(1)
{
t=MAX6675_ReadReg();
Flag_connect=t&0x04; //读出数据的D2位是热电偶掉线标志位，该位为1表示掉线，该位为0表示连接
Flag_connect=Flag_connect>>2; //MAX6675是否在线
t = t<<1; //读出来的数据的D3~D14是温度值
t = t>>4;
MAX6675_Temp = t/4; //测得的温度单位是0.25，所以要乘以0.25（即除以4）才能得到以度为单位的温度值
for(t=0; t<200; t++) //显示温度
{
Display(MAX6675_Temp);
}
}
}
