Sony IR Remote

[Ioannis]

Are you sure your IR LED lights? I mean of course you cannot see it. But with camera or your mobil phone maybe you can see if the LED is lighting.

Do not trust this very much, since my SONY DSC-W17 does not see any IR at all! So test this first with a known IR transmitter to be sure.

Ioannis

[fratello]

I test the function of my schematic with two phones camera (Nokia & S-E) ; and with InfraX soft too. I capture the signal with TSOP 1738 on serial port, for "original" remote and for "PIC" remote...Works fine...but without results on my RC ! Thanks for support !

[Ioannis]

I see a 55us diffrence in the two shots. May be this is the problem.

Ioannis

[fratello]

...and I say in previous post :

          Cycles = 102      ' 102 * 26 = 2652 uS
          CALL Pulse38
          
          Pauseus 2580      ' accurate pause of 2580 uS ?!?
          
          Cycles = 25       ' 25 * 26 = 650 uS ; maybe must EXACTLY 660 uS - how ?!?

Suggestions ? Thank You for attention !

[Ioannis]

You may very well declare a 1234usec delay but this depends on the accuracy of the System Clock (Crystal resonator or what ever).

So you may have to trim a little the value of the pauseus to get exactly the time you want.

In general IR systems I eel are able to tolerate such skews...

Ioannis

[fratello]

After thousands of re-writing this code, I've got finally results :

@ DEVICE PIC12F675, INTRC_OSC_NOCLKOUT, wdt_off, pwrt_off, mclr_off, bod_off
DEFINE OSC 4

CMCON = 7               ' Comparators disabled
ANSEL = 0               ' A/D disabled

@ #define IRTX GPIO     ; Define port to use for IR out
@ #define PIN 1         ; Define port pin for IR out


 Puls_a         CON 112  ' 112 x 26uS = 2912 mS ( pulse with carrier ON)

InterPulse  CON 2800 ' 2.80mS (delay between pulses with carrier OFF)

Puls_b        CON 28   ' 28 x 26uS = 728 uS   ( pulse with carrier ON)





X        VAR BYTE ' Data bit loop counter & bit index pointer
Duration VAR BYTE ' Duration of button press
Loops    VAR BYTE ' Loop count
Cycles   VAR BYTE BANK0 SYSTEM' Number of carrier cycles to generate


trisio=%11111101
option_reg.7=0
wpu	=%11111101

but  var gpio.5

                        

    GOTO Main       ' Jump over pulse routine to Main
    
Pulse:              ' Generate "Cycles" number of 40kHz pulses
ASM                 ; Keep this routine in code page 1, and jump over to Main
   	BSF	IRTX,PIN		      ; 1 MAKE IR HIGH 35% Duty cycle = 9 uS
	GOTO	$+1
	GOTO	$+1
	GOTO	$+1
	GOTO	$+1
	BCF	IRTX,PIN		      ; 1 MAKE IR LOW 17 uS
	GOTO	$+1
	GOTO	$+1
	GOTO	$+1
	GOTO	$+1
	GOTO	$+1
	GOTO	$+1
	DECFSZ	Cycles,F	
	GOTO	_Pulse	      ; 2    26 uS
ENDASM
   return           ' Return to caller    
    
Main:

Duration = 2    ' Send it twice

IF BUT=0 THEN    
For Duration = 1 to 2
        Cycles = Synch         ' carrier on
        Call Puls_a             ' Send pulse

        PAUSEUS InterPulse    ' Pause (carrier off)

        Cycles = Logic0        ' carrier on
        Call Puls_b             ' Send pulse

		Pauseus 50000
		Pauseus 50000
Next Duration

ENDIF    
    GOTO Main                  ' Return for more

    END

This is command for Volume Up only ; instead 102 cycles * 26 uS = 2650 uS, I put 112 * 26 = 2912, etc. So, the lenght of one pulse is 23.5 uS ?! Maybe with this PIC... Anyway, it's good to see that working, after hard work... Thank You all for support; every advice it's further wellcome !

[Ioannis]

It seems that the internal RC oscilator is not precise at least for the receiver you use.

It cannot tolerate small differencies of the transmission pulse width.

Either use a crystal oscillator or trim your delays so that they get precisely the value needed.

Ioannis