Don't fear the 50/60 Hz noise - Use it
January 1, 2009
I am sad to say that I do not get much time to build any robots these days.. However, every now & then I get a few moments in my workshop.
Thanks to OddBot I got myself some phototransistors a while back, and now I had some time to play. I was thinking of making 2 robots send little signals to each other via a light beam.
Unfortunatly it's winter time in Denmark, and so I had to work under indoor light bulbs. And as you may know; Working with pulsating light under a such can be a pain!
So I thought.. hey - if these 50 Hz are so over all dominant, and the darn phototransistor, hooked up to a Picaxe spinning 16 MhZ is so happy to pick up this "noise".. well then, why not make use of it?
So I just used a phototransistor, and wrote a few lines of code that I thought would be really "bad" for what used to be a problem.. and ended up getting myself a new sensor with an amazing thin beam, working at up to 40 CM's - as long as the target is hit by a light from an indoor lamp :)
I haven't done much testing on it, have little time, and want to do something else.. however, thought it was a quite funny thought; Let the "lightbulbs" work as a "sub-carrier" instead of trying to avoid them :)Perhaps one of you out there have more time, and wants to pick this up?
Readadc10 (read analouge in with high resolution), have a light bulb on, and read the numbers that you are getting. They are extremely steady, so the rest should give itself - the sensor could be programmed any way you'd like..