Thomas Henry Keyboard & sMs Integrated Keyboard Controller

Scott Stites · Posted: Thu May 10, 2007 1:50 pm Post subject:

Right - the CV and modulation are summed before the portamento.

Aha! I see a chink in the armor - what if I want to program the part 200,001 times? Then what? Very Happy

Cheers,
Scott

Dan Lavin · Posted: Thu May 10, 2007 6:56 pm Post subject:

Bill/Scott:

Thanks for the PLCC to DIP suggestion. I had checked my Mouser catalog and Digikey, but hadn't made it through the Jameco one yet....those are about the only 3 companies I use for components.....98% anyway. I was thinking about bandsawing up a couple regular breadboards to make this work!!!!

Bill: yeah, I'm still up for breadboarding this. When it's ready, let me know and i'll post my mailing address. Must do something with these keyboards piling up in the basement!

Thomas: now if you could just incorporate fingered portamento into the design......
No! save yourself for more module designs!

State Machine · Posted: Fri May 11, 2007 6:23 pm Post subject:

Here is a schematic of a "proven" downloader cable that will program many Xilinx devices, including the 95xxx series CPLD's. I know it works because I built one and it works great!

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State Machine · Posted: Fri May 11, 2007 6:30 pm Post subject:

Dan Lavin · Posted: Sat May 12, 2007 6:12 pm Post subject:

Bill:

yeah, I can get the cable. Although it wouldn't be too bad to build, I just don't need another project on top of the keyboard breadboarding..so I'll just buy one. Let me know your timing or give me a week notice and I'll make sure I time delivery.

I just got a new studio amp and a rack mount PC case this week, so I'm redoing my studio desk. Of course, that gives me an excuse not to record and work on circuits!

State Machine · Posted: Sat May 12, 2007 7:47 pm Post subject:

State Machine · Posted: Sun May 13, 2007 2:38 pm Post subject:

Guys,

Here is what looks to be a good website for prototyping adapters!
The prices are not that bad either.

The Keyboard circuit "integration" project is what the reason is for this post.

http://smt-adapter.com/Site/Wire-wrap-sockets,,PLCC.htm

Bill

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Dan Lavin · Posted: Sun May 13, 2007 6:52 pm Post subject:

Bill:

Thanks for all the technical support. If you are able to squeeze the circuit onto the 44 pin chip, you've have at least one thankful DIYer. Yeah, the midi option would be cool...down the road of course. I got to thinking about the fingered portamento. I think it might be easier to implement than I initially thought. The gate and trigger signals obviously already indicate legato vs staccato playing. A trigger could be derived from the gate signal and if both this trigger and the usual trigger is there, then no glide. If the normal trigger is there and the gate derived trigger is not there, then the glide is turned on. Glide is turned off by trailing edge of the usual gate signal. Glide turn on/off is a cmos switch in parallel with the glide pot. Well, that's just some initial thoughts and probably needs a lot of refining. I'm going to call that TH Kbd Rev 2 and the midi version Rev 3.

State Machine · Posted: Tue May 15, 2007 11:54 am Post subject:

Dan Lavin · Posted: Tue May 15, 2007 6:57 pm Post subject:

Bill:
Let me give you my email address for forwarding files, correspondence with Blue Hell, etc.: lavins49456 (/at/) yahoo dot com. Obviously replace the (/at/) with @ and the dot with the .

Thomas:
I was just scanning your book BABMS and just noticed there is no mention of diodes at the matrix points of the keyboard. Is that because of the low note priority is just looking at whatever is the lowest key or am I missing something? I should probably drag out John Simonton's Friendly Stories book and figure it out for myself but it's been a long day. I'm guessing as long as the diodes have the same orientation they shouldn't matter if I already have them on my kbd.

Scott Stites · Posted: Wed May 16, 2007 9:09 am Post subject:

If I may...

One unmentioned benefit of Thomas' keyboard circuit is that it frees you from the inevitable oppression of the powerful diode cartel Very Happy

In other words, with this app, you don't need diodes in the matrix. What you're looking for is a particular row and column to be connected together to provide a path to ground, or, in the case of membrane type keyboards, close enough to ground potential to pull R6 low enough to cause G4 to go high.

Notice the common input of IC8 is connected to ground - when IC8 is addressed to look at a column that is connected by a pressed key to a row addressed by IC7, it provides a path to ground from R6 through IC7 and IC8. So, in this config, no blocking diodes are needed.

Cheers,
Scott

State Machine · Posted: Wed May 16, 2007 10:11 am Post subject:

State Machine · Posted: Wed May 16, 2007 10:12 am Post subject:

Scott Stites · Posted: Wed May 16, 2007 10:16 am Post subject:

Dan Lavin · Posted: Wed May 16, 2007 10:46 am Post subject:

Scott: being in the component business myself, I can personally vouch that no one making diodes is making any money! We're doing them a favor by not using any! I did pull out my 2 books this morning and figured it out, but thanks for the good explanation for the rest of the forum members. But you do realize we are sacrificing John Simonton's 'orgasmatronic glide' arpeggiation feature!?!

Scott Stites · Posted: Wed May 16, 2007 11:03 am Post subject:

Dan Lavin · Posted: Wed May 16, 2007 1:36 pm Post subject:

Scott: on the "O"glide option, JS adds a cap between the strobe and scannot pins and runs a pot to gnd from scannot and basically creates an arpeggiator function. A parallel front panel switch turns it off when closed. Another cool feature he incorporated was a Random line where it strobes random numbers to the D/A and of course an optional pot controls the rate at which this occurs and can also make a series of ascending or descending notes. I never did incorporate either feature into my old PAIA digital keyboard....I was more interested in soloing than effects and these 2 circuits (EK-3 and 8785 Linear D/A) replaced a less than dependable double-buss sample and hold based circuit from EML.

blue hell · Posted: Wed May 16, 2007 2:16 pm Post subject:

State Machine · Posted: Wed May 16, 2007 5:55 pm Post subject:

State Machine · Posted: Fri May 18, 2007 12:09 pm Post subject:

OK, I have just about there with the keyboard controller logic integration. (I have been doing a bit at a time during lunch and coffee breaks) I put 16 chips into one. I am just adding in the ADDER circuit with the 0, 12 and 24 count offset for octave control. I promise I will have documentation so the chip will not become a "black box" as so many programmable IC's do become. I have instantiated all the logic into schematic symbols so it will read as a schematic would.

For future expansion purposes, I am staying with the XC95108 device since more features may be added as it evolves.

Bill

Scott Stites · Posted: Fri May 18, 2007 12:19 pm Post subject:

Dan Lavin · Posted: Fri May 18, 2007 12:47 pm Post subject:

Scott Stites · Posted: Fri May 18, 2007 1:08 pm Post subject: