/****PIC单片机通过SPI串口可以读取TC77传感器的温度数值****/

/****通过串口与上位机连接在串口调试工具中可显示温度的数字值**/

/*****************主程序************************/

#include "p18f4620.h"

#define TC77_CS LATAbits.LATA2                //片选信号，低电平有效

//初始化

void initial()
{
 INTCON = 0x00;
 ADCON1 = 0x07;
 PIE1 = 0;
 PIE2 = 0;
}

//串口初始化

void EUSART_Init()
{
 TXSTA = 0xA4;
 RCSTA = 0x90;
 BAUDCON =0x00;
 TRISC = TRISC|0x80;
 TRISC = TRISC&0xBF;
 SPBRG = 25;
}

//发送数据到串口

void send_ch(int d)
{
 PIR1bits.TXIF = 0;
 TXREG = d;
 while(TXSTAbits.TRMT == 0);
}

//SPI配置TC77

void TC77_init(void)
{
 TRISCbits.TRISC3 = 0;
 TRISCbits.TRISC4 = 1;
 TRISAbits.TRISA2 = 0;
 SSPSTAT = 0xC0;
 SSPCON1 = 0x20;
 PIR1bits.SSPIF = 0;
}

//读TC77温度传感器

unsigned int Read_TC77(void)
{
 unsigned char temh,teml;
 unsigned int temp;
 TC77_CS = 0;                             //片选TC77
 PIR1bits.SSPIF = 0;
 SSPBUF = 0;                              // 读高8位
 while(!PIR1bits.SSPIF);
 if(SSPSTATbits.BF)
  temh=SSPBUF;
 PIR1bits.SSPIF = 0;
 SSPBUF = 0;                          //读低八位
 while(!PIR1bits.SSPIF);
 if(SSPSTATbits.BF)
  teml=SSPBUF;
 TC77_CS = 1;
 temp = temh;
 temp = (temp << 6)+(teml >> 2);     //换算为十六位数据
 return temp;
}

//延时函数

void wait(unsigned char t)
{
 unsigned char i;
 unsigned int j;
 for(i=0;i  for(j=0;j<10000;j++);
}

//主函数

void main()
{
 unsigned int T;
 initial();
 EUSART_Init();
 TC77_init();
 while(1)
 {
  T = Read_TC77();
  send_ch(0xFF);
  send_ch(T);
  send_ch(T >> 8);
  Nop();
  Nop();
  wait(10);
 }
}