FREQOUT - PWM question

[skimask]

Well here is the data sheet to the LEDs-

http://www.jameco.com/Jameco/Products/ProdDS/106526.pdf

It says the forward voltage drop is usually 1.2V so I should be able to drive two in series along with a 150 or 200 Ohm resistor right?

I just may not get a real far detection range.

Thanks again for the help

Sounds like it's easily done, should be able to drive 3 or 4 in series without a problem. I think you're main problem will be ambient light and how to filter that out without killing your detection light.

[Etcho]

Thanks again for all the help, the parts will get to my house next week - I will let you know how it goes.