[sdiy] CPLD shield for arduino/AMANI 64/AMANI GT

Brock Russell brockr0 at shaw.ca
Tue Mar 27 21:44:27 CEST 2012 

They can buy them from Organ Service, http://www.organservice.com/

At 12:27 PM 27/03/2012, dan snazelle wrote:
>i would think a lot of people would be happy to buy a TOG replacement
>
>just think of all the projects that require them (like the PAIA EGG)
>
>
>
>
>
>On Mar 27, 2012, at 3:00 PM, Brock Russell wrote:
>
> > I agree there is probably no need to design a modern TOG. As I 
> said in my last post, while it's possible, it's probably not 
> practical to make an MK50240 clone. For me, this has been a simple 
> design exercise to learn the Silego design tools and see what the 
> parts are capable of. Some people like to flash an LED on and off, 
> I prefer to make sounds when I'm trying out a part for the first 
> time. In this case, the basic counter/divider operation is a very 
> small aspect of what the parts can do, but once I saw it was 
> trivial to get four notes from a part and they are so crazy small I 
> decided to see if it was possible to place all the parts required 
> for TOG clone in a 16 pin DIP form factor and it was.
> >
> > I'm not actually a fan of TOG instruments, I find they are noisy, 
> mine certainly is and I've got an old Wurlitzer combo organ that's 
> a wheezy thing too. I think the entire concept of a large number of 
> oscillators always on is flawed, it just happens to be something 
> really easy to design. You could put a dozen individual oscillators 
> on a board but that's not really any different. My Wurlitzer uses a 
> dozen LC oscillators.
> >
> > These parts do operate fast though, about 100MHz internally at 
> 5V. With a fast clock and a 14-bit counter I'm pretty sure you 
> could tune these things to your satisfaction.
> >
> > What am I going to do with these chips? I don't know. I'm an 
> embedded system designer with a reputation for designing the micro 
> out of small designs and that's exactly what Silego advertised 
> these parts suitable for so that's the most likely use. But I'll 
> probably make sound with it too. I just found the development board 
> is limiting for prototyping, especially for battery powered designs 
> which these parts seem ideally suited for, so that's why I decided 
> to make a dip adapter.
> >
> > Brock
> >
> > At 03:09 AM 27/03/2012, Tom Wiltshire wrote:
> >> Whilst I applaud the effort and ingenuity that is going into 
> these attempts to build modern top-octave generators, I don't 
> understand the need.
> >> The switch from separate master oscillators to one master osc 
> and a top-octave generator chip caused a notable flattening in the 
> sound of the instruments that did it, since everything got 
> phase-locked together.
> >> Wouldn't we be better off putting twelve surface mount 
> oscillators on a chip? Or are you guys so far ahead of the original 
> clock speed that it stops being such an issue? What are you 
> intending to do with these chips? Just curious, not criticising.
> >>
> >> T.
> >>
> >> On 26 Mar 2012, at 23:23, Brock Russell wrote:
> >>
> >> > I see, you're not making an MK50240 clone exactly, but making 
> a usable top octave generator. That still seems to be quite a trick 
> to get the design done to that few cells. I've been thinking of 
> going in the opposite direction, using a higher frequency clock and 
> a ten bit counter, but the MK50240 type clones I designed use the 
> same divisors as the original.
> >> >
> >> > I haven't soldered the Green PAK2 DFNs. I haven't made any 
> boards yet as I can't make boards myself with toner transfer that 
> have 0.4mm pitch parts and I didn't really want to make some single 
> design boards. I finally decided over the weekend to make some DIP 
> adapter boards that have battery back up so I can prototype with a 
> bunch of devices without having to permanently program the OTP 
> parts. The Silego development kit is two parts, the socket board 
> plugs into the main board, so I'm making a different socket board 
> with a DIP ZIF socket to handle the adapter boards. I should have 
> that up and running in a couple of weeks.
> >> >
> >> > Brock
> >> >
> >> > At 10:12 AM 26/03/2012, nvawter at media.mit.edu wrote:
> >> >> Heya!!
> >> >>
> >> >> Glad you noticed- it took a lot of work.  49 was my estimate, but my
> >> >> first draft uses 56 of the cells.  Cutting it close!  It has not been
> >> >> simulated yet, because I need to learn how to simulate in Quartus.
> >> >> The two approaches I used are to compute the minimum accuracy needed
> >> >> and to organize the dividers into a tree of chains that have common
> >> >> divisors!
> >> >>
> >> >> hmm checking out Silego programmable parts now.  interesting.  some
> >> >> nifty analog components inside those little devices, including an ADC.
> >> >> They might not be so bad for DIY..  they have free development
> >> >> software for Win as well as OSX.  They also sell dev sockets.  And,
> >> >> they have lots of how-to videos and a $50 dev kit.  They haven have a
> >> >> design library for OrCad and Eagle!  Intriguing!
> >> >>
> >> >> Did you end up solder-mounting your Silego DFNs?
> >> >>
> >> >> Quoting Brock Russell <brockr0 at shaw.ca>:
> >> >>
> >> >>> I'm kind of late picking up this thread but I have to ask, how do
> >> >>> you create a top octave generator with only 49 cells in a CPLD? The
> >> >>> Altera EPM3046A has one flip-flop per macro cell so it seems to me
> >> >>> you'd need two of these devices to generate 12 notes.
> >> >>>
> >> >>> I designed a few MK50240 clones a few months ago using 3 and 4
> >> >>> Silego SLG46400 Green PAK2 devices and some CD4504 level shifters.
> >> >>> It's actually possible to make a DIP sized plug in replacement. The
> >> >>> Silego parts aren't really DIY friendly as they are 2.5mm square 12
> >> >>> pin DFNs, but they are very cool devices containing a ton of
> >> >>> features in a 28 cent part.
> >> >>>
> >> >>> Brock
> >> >>>
> >> >>>
> >> >>> At 08:27 AM 15/03/2012, nvawter at media.mit.edu wrote:
> >> >>>> Oh, heck yeah!
> >> >>>>
> >> >>>> My friend and I are currently obsessed with recreating 
> chromatic clock
> >> >>>> divider chips.  I think a CPLD would be great for that.
> >> >>>>
> >> >>>> The Altera EPM5064 on that Arduino CPLD shield has 64 macrocells.  My
> >> >>>> estimate for a single octave MK50240 clone is about 49 cells.
> >> >>>>
> >> >>>> anyone have any other ideas for MK50240 clones that are 
> available in stock?
> >> >>>>
> >> >>>>
> >> >>>>
> >> >>>>
> >> >>>> Quoting dan snazelle <subjectivity at hotmail.com>:
> >> >>>>>
> >> >>>>> are there any SYNTH DIY uses for a CPLD/programmable logic?
> >> >>>>>
> >> >>>>>
> >> >>>>> http://majolsurf.net/wordpress/?page_id=368
> >> >>>>>
> >> >>>>>
> >> >>>>>
> >> >>>>>
> >> >>>>> http://majolsurf.net/wordpress/?page_id=1663
> >> >>>>>
> >> >>>>>
> >> >>>>> _______________________________________________
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> >> >>>>
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