555 synthesizer

Vintage ? Hush that tongue, I and many others still use those in new designs.. They work just fine, although many are sliding over to the CMOS versions and for good reason, but still the same in the end.

Jamie

As Joerg would say, too expensive. Usually you don't need much more than an oscillator or monoflop, and you'll get six of it with something like 74HC14 for the same price as one NE555. And of course, building an e-piano with 36 pots is really vintage, but then there is no way to create such authentic sound with a digital piano :-)

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

LOL

Hello Frank,

What contest did you build this for ?

What was the prize ?

Did you win ?

hamilton

It is this contest:

There are many interesting prizes:

My favorite would be a C64 Direct-to-TV :-)

I guess the winners are choosen next month. All entries must be submitted by March 1st, 2011.

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

"Frank Buss" schreef in bericht news:1b0skrzw3bcos$.1wtd8wupo58x1$. snipped-for-privacy@40tude.net...

Last januari, Elektor published an article which stated that the 555 was becoming obsolete and said them to be replaced by Atmel ATtiny25. I cannot agree even if I tend to use micros (PICs) for tasks that were done by 555s in the past. It's for sure that micros can do a lot of things that 555s cannot but still there are many things that can be done using a 555 that cannot be done using a micro. The price performance ratio may also favor the

555. I wrote pretty long a comment on the Dutch Elektor forum you may like to read. (If you can read Dutch that is.)

petrus bitbyter

The 555 works up to 500 kHz. Modern microcontrollers have many MHz internal clocks, so if jitter doesn't matter, it should be possible to do most 555 projects with an ATtiny25.

But you are right, the ATtiny25 looks a bit expensive. Maybe take a look at the MC9RS08KA2CSC or the 12F-PIC series.

But one drawback will be that you have to program the microcontroller and it can become obsolete, something which would never be the case for the 555 for the next some decades. And the flash of a microcontroller can lose data.

I can try it, it is not that much different from German. Do you have a link?

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

On a sunny day (Sun, 27 Feb 2011 19:34:26 +0100) it happened "petrus bitbyter" wrote in :

I sort of disagree, have not read your comment, as you give no link. I looked at that organ, and just went 'OK', but why do it? For the prize money? A little while ago I threw away lots and lots of old electronics I build, because it was too heavy for my spacecraft. Sure if you want to make a VFO controlled by a pot, then 555 is nice. But it nothing original, I would not award the prize for it, of course I would not bother with 555 contest either. Many if not most applications can be done with a PIC or some other micro for perhaps less, as you likely need less external components, use less power, need only one part in stock, and can do more in software than the a 555 hardware ever can. I also threw away tubes of cool old TTL and HC / HCT 74 chips... Even micros... Z80, stuff like that. Same for all those old books about assembly language programming on old micros like that, my ADA book, all books that had MS on it one way or the other, including the disks, like for example Visual Basic, all that shit, it is a bit with all that old stuff like if you have a harddisk crash: "Oh well it is all gone, life goes on, let's do something new." No tears, goodbye 555 no problem. I may still have one (not sure). There is one as timebase in my old Trio analog scope, replaced it once.

There is no money, but some cool gadgets from the sponsors. But the PCB, the parts and the hours I've spent on it are worth more than most of the prizes, I've done it for fun.

Of course, with a PIC you can do it much more simpler, without all these pots. If you use one with PWM output, it is no work at all and changing the duty cycle could result in more interesting sounds.

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

And thatis a nice application for a 555 I think:

I hope the website works, it is hosted in the US, but comes from a server in the Netherlands now...

On a sunny day (Sun, 27 Feb 2011 20:16:31 +0100) it happened Frank Buss wrote in :

I was much more impressed with your nice video reporting :-)

Thanks, but I think I have to learn to speak better English :-)

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

On a sunny day (Sun, 27 Feb 2011 20:29:25 +0100) it happened Frank Buss wrote in :

LOL, I have ben all over the US, and trust me, in Florida / miami they speak all Spanish :-) Even large parts of LA, same thing.

Jan,

Please take a lesson about schematics, prototype construction and presentation.

hamilton

You have to balance it: It needs time to do a good presentation. Jan's projects are cool and personally I don't care about presentation. My project is nothing new, but with a good presentation. Doing both needs too much time.

But for some schematics I would be happy if Jan would at least create a clean drawing of it with a black pen on white paper before scanning.

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

This is the whole link:

petrus bitbyter

In engineering there are three criteria:

Time, Cost, Works

( I know, pick two)

In open source or open designs:

Works seems to be the only criteria.

Thanks, the Google translator did a good job for translating it to German. But I didn't found an application in your article which the 555 can do and a microcontroller can't do. From your detailed comparison with a PIC, the only advantages of the 555 are higher power output and higher possible operating voltage, and that you need to program the PIC. And of course the

555 is manufactured by many companies.

--
Frank Buss, http://www.frank-buss.de
piano and more: http://www.youtube.com/user/frankbuss

It's not only the higher voltage, it's the range in which the 555 functions. A 555 will keep functioning even if it's supply voltage is changing by volts due to load or powersource variations. As a simple, cheap timer in a non- stabilized supply voltage environment it cannot be beaten by a PIC.

In a monostable configuration a 555 has a short, fixed reaction time. A PICs reaction time can hardly be shorter and will always vary as interrupts will generally not be synchronous with the PICs clock.

As an oscillater a 555 will beat the PIC in higher frequencies. A 555 also will be tunable at this higher frequencies while a PIC will be bound by multiples of its machine cycle.

petrus bitbyter

200mA output current too IIRC (haven't used one for 20 years...).

--

John Devereux