IR problems

[Bruce]

Here's one example using a comparator. http://home.cogeco.ca/~rpaisley4/ATDetIR.html

[mackrackit]

Here is one I am using for a "Laser Fence". It will also work for IR.

And the simple code to go with it.

DEFINE OSC 4

Asm
    ERRORLEVEL -306
Endasm

include "modedefs.bas"

ANSEL=%00000000
CMCON=7

PAUSE 2000

TRAIN	VAR BYTE

TRAIN=$55
CNT	VAR BYTE
LP	VAR BYTE

START:
COUNT PORTC.1,100,LP
IF LP <> 1 THEN CHECK
HIGH PORTC.5
PAUSE 50
LOW PORTC.5
PAUSE 50
GOTO START

CHECK:
COUNT PORTC.1,100,LP
IF LP <> 1 THEN BREACH
GOTO START

BREACH:
FOR CNT = 1 TO 5
SEROUT PORTC.4,T2400,[TRAIN,TRAIN,TRAIN,TRAIN,TRAIN,9,3]
HIGH PORTC.5
PAUSE 100
NEXT
GOTO START

END

R2 will adjust the sensitivity of the Photo Diode. Ambient light does need to be shielded. Have used the same with IR but R2 was a fixed 10meg. (Total darkness for a parts counter on a conveyor)

Using 3 volts because of the radio transmitter.

[mackrackit]

Looks like I need a lesson on image tags!
<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=1904&stc=1&d=118608738 4">

Got it!!

[Snap]

I am happy there are more people out there building things for their .....ahem..childrens amusment. Mine is a slot car track for my son. Bruce small internet I used the exact same schematic you sent me for the lay out and it is the one that is giving me the problems but Im sure I am being too sticky about the details and tonight I will try it out with the pic with the fence circuit and see how it works (in sure it will be great).
Thanks again for the help I will post if it works or not.
Snap

[Pic_User]

Looks like I need a lesson on image tags!

Found this:
[html]<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=367">[/html]By: Darrel
Here:
http://www.picbasic.co.uk/forum/show...98&postcount=2

[mackrackit]

Found this:
[html]<img src="http://www.picbasic.co.uk/forum/attachment.php?attachmentid=367">[/html]By: Darrel
Here:
http://www.picbasic.co.uk/forum/show...98&postcount=2

Thank you Pic_User! Learn something every day.

[Snap]

Ok, I got my ir detect to work on a pic 16f84a the secret is to ignore all of the internet info out there that suggest op amps comparators. The pic is smart enough to read a slightly variable input (you might have to pull up of down the port). and job is done. After all was working It still bugged me that I could not get the 741 op-amp working so I spent the night playing with diffent combinations of resistors and leds untill I thought I figured this little sucker out of course I will be wrong ...but I can tell you that the fence circut works.
Thank again for the speedy help
Snap