I want to use one of my Arduino Unos to create a small "fence".
This fence will be about 25-30 feet total length.
It will be made up of a light beam... which, if interrupted, will trigger one of the Uno's outputs.
I was thinking of using a small laser for the fence, yet I hace two questions:
1- will normal daylight trigger the photodetector, so it's always triggered? (this is not desireable)
2- what light source could I use? I thought of using a laser, yet I have doubts if 24/7 operation would overheat it?
So, any thoughts on what light source could I use? And the photodetector, any suggestions?
There is no problem with 24/7 use of a laser. If you are using a laser and the detector is sensitive only to the frequency of the laser then day light will not be a problem.
What will be a real problem is setting up the laser a getting it on target.
WaxFlywheel:
1- will normal daylight trigger the photodetector, so it's always triggered? (this is not desireable)
2- what light source could I use? I thought of using a laser, yet I have doubts if 24/7 operation would overheat it?
Depends entirely on the distance travelled by the beam, the frequency of the light, the frequency the detector detects, and a few other things. Experiment with a variety of detectors. IR might be better than blue, for example. Try filtering the light falling on the detector to narrow the range of what comes through (check out the filters in the front og IR remotes). Modulate the beam, and look at the output of the detector, testing for that modulation.
A laser diode might be best, but life could be a problem. Experiment.
I have no idea if it will work, but it's worth trying things, I think.