I need to detect a device in my car. It has audible tones that I am building a lm567 circuit for now. However the same trigger can be achieved if I could find a way to detect that little yellow led with the same accuracy. ONLY the yellow led, not the green red or anything else, without obstructing it and must be VERY reliable.

Can it be done inexpensively?

Thanks.

 

Hi Pablosan
You can use optical detector for detecting yellow led.

 

Thanks. I was looking for an inexpensive solution to detect the exact wavelength of my yellow led ONLY. Not all the ambient light. I found this cell phone spectrometerhttp://www.asdlib.org/onlineArticles/elabware/Scheeline_Kelly_Spectrophotometer/index.html
about the same as photoshop I think.

May not be accurate enough....

I was looking to build something like this http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&ved=0CHgQFjAI&url=http%3A%2F%2Fwww.first-sensor.com%2Fsites%2Fwww.first-sensor.com%2Ffiles%2Fdownloads%2Freferencesolutions%2Fentwicklungsmodule%2Fws756pcba2_500008.pdf&ei=EFdnT-WGMuPZiQLVl5SjDw&usg=AFQjCNGezdbNJ76OFVMWBsk8q_E0-wi3pQ&sig2=XxhFX2Pw9pevcwuNC41Fww

 

You can use another yellow LED as a photodetector.

http://www.parallax.com/Portals/0/Downloads/docs/prod/robo/LEDLightEmitterandDetector7-31-07.pdf

 

Are you trying to detect the indications from a concealed remotely mounted radar detector?

 

Same idea ! Its for a Ignition interlock device.

I can't hear the tones with the stereo on and the led is anything but attention grabbing.

Its actually dangerous because I'm ALWAYS taking my eyes off the road to check if its yellow not green and you can't hear it.