howell.c

这是一个用于视频切换的控制程序,采用AT89C51芯片,KEIL 51开发

#include " reg52.h"
#include "main.h"
#include "string.h"

unsigned char data dvr_set;                           //cumputer set or cancel alarm
unsigned char data t;
unsigned char data s;
unsigned char tbuf[8];
extern bit flag_ea;





unsigned char code My_Array1[6]={0x4a,0x44,0x41,0x43,0x46,0x4b};
void delay1ms(unsigned char  count);

//extern void com_isr(void);
/*------------------------------------------------------------------
                send the data sbuf
  ------------------------------------------------------------------*/
void send_char_com (unsigned char ch)
{ 
  	SBUF=ch;
	while(TI==0);
	TI=0;
} 
/* -----------------------------------------------------------------
             deal with the dvr inquire command
   -----------------------------------------------------------------*/
 void alarm_in (void)
{
 unsigned int i=0;
 RT_CON=1;
 delay1ms(1);
 tbuf[0]=0xf6;
 tbuf[1]=0x01;
 tbuf[2]=0x4b;
 tbuf[3]=0x08;
 tbuf[4]=(~P0 & dvr_set); 
 tbuf[5]=0x00;
 tbuf[6]=tbuf[1]+tbuf[2]+tbuf[3]+tbuf[4]+tbuf[5];
 
   
	do
	{
		send_char_com(tbuf[i]);
	//	delay1ms();
		i++;
	} while(i <7 );
 RT_CON=0;
 } 
 


  


extern void howell(unsigned char rbuf1[8])
{
 unsigned char data i;



/*	  if(r_out!=7)
      {
	  
	  r_out = 7;
	  r_in = 1;
      EA=1;
      }*/


	   s=rbuf1[2];
	   for(i=0;i<5;i++)
	   {
	    t=My_Array1[i];

        if(t==s)
         {
		  switch(i)
		  {
		   case 0:alarm_in();
		          break;
		   case 1:P2=~rbuf1[4];
		          break;
		   case 2:dvr_set=rbuf1[4];
		          break;
		   case 3:
		          break;
		   case 4:
		          break;
		  }
                    break;
	    }
	  }
//      LED=0;
	//  r_out=7;
     // r_in=0;
	  flag_ea=1;
	 
     }