It uses an IR photo resistor inventorArtist » Blink Detection for ALS
inventorArtist:
It uses an IR photo resistor inventorArtist » Blink Detection for ALS
Neat idea - does daylight/sunlight cause problems?
Not sure yet. I think it might.
But it all depends on the application and how much the sun is shielded...
MarkT:
Neat idea - does daylight/sunlight cause problems?
Not necessarily - as with most analog detectors, you are looking for relatively rapid changes, so you use a "high pass filter" of some sort in the software. And someone using this device is rather unlikely to be moving about in chopped sunlight. Being in sunlight would of itself, simply be a supplementary source of IR radiation to the LED; as long as the detector can handle the levels, that need not be a problem.
Good point.
My software (which was written only in a few minutes for proof of concept) only responds to rapid change. So the sun might be a constant.
But what I wasn't sure about was if it would wash out. Perhaps the sun could be very bright compared to the LED and the change due to the LED would bet lost in noise...
But MarkT, the sensor is 20 cents and the circuit is trivial so you could try it. If you want the sensor, send me an email (from my contact page at my web site). I have a few extra. I can even print you the glasses if you want.
If only I had time...