dania25:
Too bad I don't have more time this month! I'll put my crazy Idea out there for some brilliant and bored member here to undertake...Basically, I want to use 555s to play "fur elise" with no logic involved. With enough 555s, you could run each of them on a precise cycle to control two or more 555s which would be the tone generators outputting through speakers. By using other 555s to control several (dozen) resistors to vary r1/r2 values, it would be possible to send the correct frequencies to the tone generating 555s- at the correct time. One master 555 could control the whole loop, repeating the tune every minute or so!
hmm, here are the frequencies and r2 values for the tones for the notes during the first 30 seconds of 'fur elise' These would assume an r1 value ~1/10th of the r2 value, and a .1uF cap.
frequencies needed:
329.628 r2= 21236ohm, cap=.1uF
311.127 r2 = 22508
293.665 r2 23890
261.626 r2 26819
246.942 r2 28455
220.000 r2 31818207.652 r2 = 33816
164.814 r2 = 42862
146.832 r2 47945
130.813 r2 53846
110.000 r2 63636
103.826 r2=67961ohm cap = .1uFGood luck!
-d
You gettin' a +1 for that. That's one cool idea. Shame I don't have enough 555s