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How would i start with interrupt driven IR RC5 using AVR ?

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Terminator Electricity

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avr interrupt driven ir decode

Hi ,,,
I have successfully made a c code for reception of IR RC5 code using ATmega16 with the help of the avr application notes

BUT i dont know how to write or how to start to write an interrupt driven RC5 IR recever

I am using codevision ,, plz could anyone help me to how to start ? cuz i was totally lost here ,, cuz no reference found on that subject

Thanks
 

Terminator Electricity

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input capture in avr

This is my code for IR RC5 reciever using an ATmega16

Code:

Code:
/*****************************************************



Chip type           : ATmega16L
Program type        : Application
Clock frequency     : 7.372800 MHz
Memory model        : Small
External SRAM size  : 0
Data Stack size     : 256
*****************************************************/

 
void setup_AVR();
#define CHECKBIT(ADDRESS,BIT) (ADDRESS & (1<<BIT))
#include <mega16.h> 
#include <stdio.h>
#include <io.h>
unsigned char temp=0;
unsigned char command[10]={0};
unsigned char system[10]={0};
unsigned char timerH=0;
unsigned char timerL=0;
int bitcnt;                     //number of bits waiting to be recieved
unsigned char ref1;                     // 3/4 bit_time
unsigned char ref2;                     // 5/4 bit_time     
int i=6;   
int j=5;
int k;

interrupt [TIM0_OVF] void timer0_ovf_isr(void)
{
timerL++;                              //increments every 255* 1/7.372800 seconds
temp++;                             
if(temp==255) {temp=0;timerH++;} //increments every 255*255* 1/7.372800  seconds
}

void main(void)
{
setup_AVR();



#asm("sei")

while (1)
      { 

initialize:   temp=0;
      timerH=0;   
           
detect1:   timerL=0; 
             
detect2:   if(timerH>15)   //If no start bit detected within 132ms
                goto fault;
                               
      if(timerL>102)   //If line high for more than 3.5ms
      goto start1;   //then wait for the first start bit

      if(!CHECKBIT(PIND,2))           //If line is :
           goto detect1;   // PIND=0  low  - jump to detect1 and reset the timer
      else goto detect2;   // PIND=1  high - jump to detect2 and recheck for 3.5 ms of ideal high

start1:      while(CHECKBIT(PIND,2))//keep checking for the first start bit
                {
                if(timerH>15)   //If no start bit detected within 132ms
                 goto fault;   //then exit    printf("5");
                }

      timerL=0;   //Measure halflength of start bit     
      
start2:      while(!CHECKBIT(PIND,2))//Measure halflength of start bit (low level length)
                {
                if(timerL>26)   //If startbit longer than 1.1ms,
      goto fault ;   //   exit
                }
                //timerL = 1/2 bit time
      ref1 =3.0*timerL/2.0;        //ref1 = 3/4 bit time
      ref2 =5.0*ref1/3.0;        //ref2 = 5/4 bit time
                timerL=0;
               
start3:      while(CHECKBIT(PIND,2))//check if second starting bit is recieved
                {
                if(timerL>ref1)   //If rising edge is too long
      goto fault;   //exit
                }
               
      bitcnt  =12;   //Receive 12 bits
                j=5;            //For command
                i=5;            //For system
sample:      timerL  =0 ;
                while(timerL<ref1); // wait untill first 1/4 of next bit   
               
                while(bitcnt>0)
               
      {
      //Now recieving first 7 bits including the toggle bit
      while(bitcnt>6)
           { if (PIND.2==0){                             //The bit recieved is 0
                              system[i]=0;               //store the bit in system
                              i-- ;bitcnt--;             //prepare for the next bit
                              while(!CHECKBIT(PIND,2))   //wait untill the next edge
                                {
                                if(timerL>ref2) goto fault;
                                }
                              goto sample;               //wait for the next bit
                           }
                     
                       else          {                             //The bit recieved is 1
                                        system[i]=1;               //store the bit in system
                                        i-- ;bitcnt--;             //prepare for the next bit
                                        while(CHECKBIT(PIND,2))    //wait untill the next edge
                                          {
                                          if(timerL>ref2) goto fault;
                                          }
                                        goto sample;               //wait for the next bit
                                     }
                     }                 
                //Now recieving last 6 bits
                                                                                     
                if(PIND.2==0){                                     //The bit recieved is 0
                                command[j]=0;                      //store the bit in command
                                j-- ;bitcnt--;                     //prepare for the next bit
                                while(!CHECKBIT(PIND,2))           //wait untill the next edge
                                  {
                                  if(timerL>ref2) goto fault;
                                  }
                                goto sample;                       //wait for the next bit
                              }                                 
               
                else         {                                      //The bit recieved is 1
                                command[j]=1;                       //store the bit in command
                                j-- ;bitcnt--;                      //prepare for the next bit
                                while(CHECKBIT(PIND,2))             //wait untill the next edge
                                  {
                                  if(timerL>ref2) goto fault;
                                  }
                                goto sample;                        //wait for the next bit
                             }
               }       
               


   
printf("aa");
for(k=5;k>=0;k--)
printf("%d",command[k]);
printf("bb");
for(k=5;k>=0;k--)
printf("%d",system[k]);

fault:      goto initialize;

      };
}
void setup_AVR()
{
PORTD=0x00;
DDRD=0x00;
TCCR0=0x01;
TCNT0=0x00;
OCR0=0x00;
TIMSK=0x01;
ACSR=0x80;
SFIOR=0x00;
}
how do i change it to be interrupt driven ? plz help
 

firmware

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avr ir capture and

Two way can do.
First :
Use input capture pin to detect the IR signal, I'm not sure AVR already provided this feature or not, try to check on data sheet.

Second :
Use one external interrupt plus one timer, start the timer counting when a IR signal come to the external interrupt pin.
 

Terminator Electricity

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interrupt driven rc5

i think input capture is a very fine method,,, got any resources plz?
 

segmex

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rc5.h+avr

kittythai said:
http://www.wara.com/modules.php?name=News&file=article&sid=610

Sony Protocal

thanks


BUT this is an indian web site POST the english one .thanks
 

firmware

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rc5 by avr

Terminator Electricity said:
i think input capture is a very fine method,,, got any resources plz?
Checked on 16bit Timer, already provided the input capture function via ICP1 pin, try to use this to decode IR signal.:D
 

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