IR Counter

[partime]

Thanks again for your help Dave. I pretty much used your RF receiver code and modified it for use with the IR signal. Here is the code I used on an 16F84A with a 4 MHz crystal. I used it to test if the channel up button was pressed on the remote.

define PULSIN_MAX 968

IRPIN           var     PORTB.0
LED             var     PORTB.1
LED2            var     PORTB.2
RF              var     byte[4]
Header          var     word
PULSE_LENGTH    var     byte
i               var     byte

INIT:   RF[0]=0
        RF[1]=0
        RF[2]=0
        RF[3]=0
        i=0
        Pulsin IRPIN, 0, Header
        if (Header < 792) then INIT
        while irpin = 0:wend
        repeat
            pulsin IRPIN, 1, PULSE_LENGTH
            if (PULSE_LENGTH < 40) or (PULSE_LENGTH > 175) then INIT
            if (PULSE_LENGTH > 90) then 
                RF.0(i) = 1
            else
                rf.0(i) = 0
            endif
            i=i+1
        until (i>31)
        if (RF[3]=230) then 
        high LED
        pause 500
        low LED
        else
        high LED2
        pause 500
        low LED2
        endif
        goto INIT
end

I get LED to go high when I press the channel up button.

It took me awhile to figure out how the data was arranged in the array. I started out using RF[0]=10 to light LED, but kept getting LED2 to light up. So, I thought there was something screwed up with the values pulsin was generating. Finally, I read through the FAQ on arrays and figured out my problem. I used RF[0]=80 and got LED to light up. However, LED would light up with any button I pushed since all the buttons used the same starting code. So, I ended up using RF[3] to test if channel up was pressed.

Is testing RF[3] going to be the best way to determine which button is pushed? I plan to use channel up/channel down for one team and volume up/volume down for the other team.

[dhouston]

Is testing RF[3] going to be the best way to determine which button is pushed? I plan to use channel up/channel down for one team and volume up/volume down for the other team.

The way most use this protocol, RF[0] indicates a device (e.g. TV, CD player) and RF[2] indicates a button (e.g. number, Vol+). RF[1] is the bitwise complement of RF[0] and RF[3] is the bitwise complement of RF[2]. So, you are probably safe using either RF[2] or RF[3].

I would suggest a change...

        while irpin = 1:wend

That merely waits until the initial space part of the header passes. With RF I found that was necessary.

[dhouston]

Also, since the array elements are reset to zero at the top of the loop, you can simplify this...

            if (PULSE_LENGTH > 90) then 
                RF.0(i) = 1
            else
                rf.0(i) = 0
            endif

to this...

            if (PULSE_LENGTH > 90) then 
                RF.0(i) = 1
            endif

And, while errors are less likely with IR, you can detect them buy adding RF[2] and RF[3]. They should always sum to 255 or $FF.