ir.c

建立在AVR基础上的测试LED数码管电压表

/******************************************************************************
*	Compiler:		WinAVR(GCC)
*	Device:			ATtiny13
*	File name:		IR.c
*	Description:		IR

*	Programmer:		Liansen.Wang
*	Revision:			1.0
*	Modification Time:	2005-08-22	14:43

******************************************************************************/
#include "IR.h"

/*===========================================================



===========================================================*/
unsigned char IR_Time_detect(unsigned int time1,unsigned int time2)
{
unsigned int i=0;
unsigned char j=0;
while((PINB & (1<<IR))>=j)
	{
	i++;
	if((PINB & (1<<IR))!=0)	{j=1;}
	if(i>time2) {return 0xFF;}
	}
if(i>time1){return 1;}
else {return 0;}
}
/*===========================================================


============================================================*/
unsigned char IR_Value_Read(void)
	{
	unsigned char i,j,k;
	unsigned char	IR_Value_time[4];

	if (IR_Time_detect(2400,3360)!=1)
		{
		GIFR|=(1<<PCIF);
		return 0xFF;
		}

	for(i=0;i<4;i++)
		{
		for(j=0;j<8;j++)
			{
			IR_Value_time[i]>>=1;
			k=IR_Time_detect(800,1440);
			if(k==0xFF) 
				{
				GIFR|=(1<<PCIF);	
				return 0xFF;
				}
			if(k==1) 	
				{
				IR_Value_time[i]|=0x80;
				}
			}
		}

	if((IR_Value_time[2] & IR_Value_time[3])==0)
		return IR_Value_time[2];
	else
		return 0xFF;
	}