555 Contest

In case anyone hasn't seen this, there is a cool 555 timer contest going on. It is actually being judged by Forrest Mims! http://www.555contest.com/

Heh - that does sound like a cool contest - I'll have to check it out! Thanks for posting that!

:)

OK here's what we do.

Rub the Atmel writing off an Attiny85 and add something like NE555. Then write a nifty program that does something not too fancy (that will give the game away) but that will knock to socks off a 555 circuit ]:D

What's the first prize anyway, a tube of 555s.


Rob

What's the first prize anyway, a tube of 555s.

Nahh, a pretty hefty chunk of stuff probably

guaranteed winner design something that needs 555 of the little suckers! :)

I'm not sure what the actual prizes are, but they are being sponsored by DigiKey and Beagle Boards among others. Also just read Hanz Camenzind who created the chip is also judge!

I was thinking 555 LEDs in a project but that involves buying more...

Yeah the prizes should be pretty epic! :D

Very clever. Is Attiny85 pin-compatible with 555?

Graynomad: OK here's what we do.

Rub the Atmel writing off an Attiny85 and add something like NE555. Then write a nifty program that does something not too fancy (that will give the game away) but that will knock to socks off a 555 circuit ]:D

What's the first prize anyway, a tube of 555s.


Rob

Rub the Atmel writing off an Attiny85 and add something like NE555.

I predict that it will have trouble driving 200mA through an output from a 12V supply...

The AVR reset circuit discussed recently isn't totally out of the running, though. A bit on the simple side.

How else might a 555 be used together with a microcontroller? This would at least be an area that hasn't already had hundreds of 555 circuits already published!

liudr: Very clever. Is Attiny85 pin-compatible with 555?

not even close

The capabilities of the 555 IC have been way overrated for some reason :P BTW Do you get extra points for building a working 555 on a breadboard with discrete transistors from the schematic? :D

They now have a list of sponsors and prizes totaling over $6,000, including a Fluke 287 and a BeagleBoard-xM! http://www.555contest.com/prizes-sponsors/

Pauly: They now have a list of sponsors and prizes totaling over $6,000, including a Fluke 287 and a BeagleBoard-xM! http://www.555contest.com/prizes-sponsors/

I have to admit, I was thinking of entering but since that guy's done the self balancing thing with a 555, I'm not going to.

No way I can top that.

You know, mowcius, there are different categories - so you could submit something fundamentally different.

Does it have to be a working circuit? I have this idea of completely covering a baseball hat with glued on 555 chips. I guess if it does have to do something electrically I could glue leds on top of the 555s. Damn battery will probably give me a headache.

I'm sure that hasn't been done before, and don't none of you go stealing my idea, just because Arduino is open sourced and all.

There is also prizes just for participating, so it might be worth submitting an entry regardless...

jezuz: You know, mowcius, there are different categories - so you could submit something fundamentally different.

True but I can't think of anything! :D

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 31818

207.652 r2 = 33816
164.814 r2 = 42862
146.832 r2 47945
130.813 r2 53846
110.000 r2 63636
103.826 r2=67961ohm cap = .1uF

Good luck! :stuck_out_tongue:

-d

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 31818

207.652 r2 = 33816
164.814 r2 = 42862
146.832 r2 47945
130.813 r2 53846
110.000 r2 63636
103.826 r2=67961ohm cap = .1uF

Good luck! :stuck_out_tongue:

-d

You gettin’ a +1 for that. That’s one cool idea. Shame I don’t have enough 555s

I've been using 555's for A to D converters for over 30 years!

Just use the 555 in monostable mode, with your resistive sensor as the timing element, trigger the 555, count till it triggers. You can do the same thing with a capacitive sensor.

Every joystick interface that wasn't a switched stick, from the Apple 2 right up to the PC works this way.

Only bad thing is you have to wait, unless it's a bit of hardware doing the counting. The dual, quad and octal 555 variants can be tricky, they tend to interact with each other, so you gotta decouple the power rails pretty well.