ir_8515.c

Atmel 8515 RC5 decoder

/************************************************************ 
* Program: AVRGCC - RC5 Test 
* Comments: RC5 decoder 
* target mcu: 8515 
***********************************************************/ 
#include <io.h> 
#include <interrupt.h> 
#include <signal.h> 
#include "lcd.h" 

unsigned int heartbeat=0; 

// RC5 variables & definitions 
#define PRSC1_SELECT 2 // timer CLK/8 
#define TRUE 1 
#define FALSE 0 
#define IRDet bit_is_set(PIND,PD2) 
volatile unsigned char RC5RxAddress, RC5RxCommand; 
volatile unsigned char RC5Avail=0, RC5Repeat, RC5PhaseErr; 

void delay(unsigned int p) 
{ 
	unsigned int i; 
	unsigned char j; 
	for(i=0;i<p;i++) 
		for (j=0;j<100;j++)
		  ; 
} 

/* signal handler for timer1 overflow interrupt */ 
SIGNAL(SIG_OVERFLOW1) 
{ 
	static unsigned char RC5BitCnt=0; 
	static unsigned int RC5Data; 
	static unsigned char OldValue; 
	static unsigned char ControlBit; 
	
	// Load Timer again... 
	outp(0xFC, TCNT1H); // set TCNT1 // 889us 
	outp(0x87, TCNT1L); // set TCNT1 
	
	if (RC5BitCnt==0) { 
		RC5Data=0; 
		OldValue=IRDet; 
		RC5PhaseErr=FALSE; 
	} 
	
	if (RC5BitCnt<24) { // sample 24 bits 
		if (RC5BitCnt & 0x01) { 
			if (OldValue!=IRDet) { // check for Biphase error 
				RC5Data <<= 1; // next bit; 
				if (IRDet) 
					RC5Data &= 0xFFFE; 
				else 
					RC5Data |= 0x0001; 
			} else RC5PhaseErr=TRUE; // biphase error 
		} 
		RC5BitCnt++; 
		OldValue=IRDet; // remember signal level 
		
	} else { // if >24 then finish 
		outp(0 , TCCR1B); // stop timer 1 
		RC5BitCnt=0; // prepare for next time 
		if (!RC5PhaseErr && !RC5Avail) { 
			RC5Repeat=ControlBit==((RC5Data & 0x0800)==0x0800); // if new controlbit=old then RC5Repeat=1 
			ControlBit=((RC5Data & 0x0800)==0x0800); // new controlbit 
			RC5RxAddress=(unsigned char)((RC5Data & 0x07C0)>>6); 
			RC5RxCommand=(unsigned char)(RC5Data & 0x003F); 
			RC5Avail=TRUE; // RC5 code is vailable... 
		} 
		RC5PhaseErr=FALSE; 
		outp(0x40, GIMSK); 
	} 
} 

/* signal handler for external interrupt int0 */ 
SIGNAL(SIG_INTERRUPT0) 
{ 
	outp(0x00, GIMSK); // disable external int0 
	outp(0xF3, TCNT1H); // set TCNT1 // 3111 us 
	outp(0xD9, TCNT1L); // set TCNT1 
	outp(PRSC1_SELECT, TCCR1B); // start timer1 
} 

/* initialize RC5 decoder */ 
void RC5_init(void) 
{ 
	cbi(DDRD,PD2); 
	sbi(PORTD,PD2); 
	
	outp((1<<ISC01), MCUCR); // raise int0 on falling edge 
	outp(0x40, GIMSK); // enable external int0 
	
	outp(0x80, TIMSK); // enable timer1 Overflow interrupts 
	outp(0x00, TCCR1A); // disable PWM and stuff 
	outp(0x00, TCCR1B); 
	outp(0xF3, TCNT1H); // set TCNT1 // 3111 us 
	outp(0xD9, TCNT1L); // set TCNT1 
} 

/* main routine for testing */ 
int main(void) 
{ 
	sei(); // enable interrupts 
	
	RC5_init(); 
	lcd_init(); 
	
	lcd_control(1,0,0); 
	lcd_putstr("RC5 decoder"); 
	lcd_goto(0x49); 
	lcd_putstr("PErr="); 
	while(1) 
	{ 
		lcd_goto(0x0E); 
		printhex(heartbeat++); // heart beat :) 
		
		if (RC5Avail) { // display new RC5 data 
			lcd_goto(0x40); 
			printhex(RC5Repeat); 
			lcd_putch( ); 
			printhex(RC5RxAddress); 
			lcd_putch( ); 
			printhex(RC5RxCommand); 
			RC5Avail=FALSE; // ready to get new one 
		} 
		lcd_goto(0x4E); 
		printhex(RC5PhaseErr); // error check 
		delay(1000); 
	} 
}


=========================================================


#pragma interrupt_handler IceInt:6 //中断程序说明
void ICEInit(void) //T/C1初始化
{
 TIMSK=0X20; //使能捕获中断
 TCCR1A=0X00； //T/C1时钟与系统相同，本文使用系统AVR内部自带1MHz振荡源.T/C1时钟周期为1μs
 TCCR1B=0X81； //使能噪音抑制，下降沿触发中断
}

void IceInt(void)
{
 static nint oldFall;
 uint temp,newFall;
 
 newFall=ICR1;
 temp=newFall-oldFall; //计算脉冲加间隔的时间
 oldFall=newFall;
 if(temp>1024 && temp<1225) // "0"信号
 {
  temp=0;
 }
 else if(temp>2145 && temp<2345) //“1”信号
 {
  temp=1;
 }
 else if(temp>13400 && temp<13600) //header信号
 {
  bitcnt=0;
  data0=0;
  data1=0;
  return; //返回，等待下次开始接收
 }
 else ///干扰信号
 {
  return;
 }
 
 bitcnt++;

 if(bitcnt<16) //开始接收前16位
 {
  data0=data0|(uint)temp;
  data0=data0<<1;
 }
 else if(bitcnt==16)
 {
  data0=data0|(uint)temp;
 }
 else if(bitcnt<32) //开始接收后16位
 {
  data1=data1|(uint)temp;
  data1=data1<<1;
 }
 else if(bitcnt==32) //接收完最后一位
 {
  data1=data1|(uint)temp;
 }
}