Alternative Control Surface

[NorthernLightX]

Hi Guys,

while I am trying to finish my projects that have been boxed for years I run into some stuff I have no experience with. I can choose two paths:

1. Abandon my funky wishlist and just stick with the default configs, or

2. Go ahead and try to build it like I originally wanted it.

I'm investigating if option 2 is within my skillset. I layed out an alternative control surface in FPD, it consists of 34 buttons and 5 encoders, totalling 44 inputs, so I would need a DINX6 module (or 2 DINX4 of which one can be half-stuffed). I have some experience in laying out PCBs so creating the DINX6 is not the problem. I on the other half have no experience in editting Midibox firmware yet, so I need to ask this:

Is it possible (without too much touble! I'm still n00b) to make MBFM support 2 extra DIN registers?

Thanks in advance!

[Shuriken]

Hardware wise it would not be a problem. But you need to make some considerable changes to the source code. Since its all in assembly it's not so n00b friendly.

Edited August 11, 2011 by Shuriken

[NorthernLightX]

Hardware wise it would not be a problem.

I expected that, the only possible problem I could think of would be memory constraints.

But you need to make some considerable changes to the source code. Since its all in assembly it's not so n00b friendly.

Would I? It's only a remap of already available functions. I'll look into the link you posted, thanks.

[NorthernLightX]

OK so I found that the file with the DIN mappings is cs_menu_io_tables.inc. The normal functions don't look too complicated but the matrix section is more complex; too complex for my current skills. If I would try to implement the one-button-per-function approach via the one-din-per-button solution I would need much help

An other option would be to keep the matrix, but to try to use multiple buttons in that matrix. I looked at mbfm_din_default.pdf and mbfm_dout_default.pdf and I think it would be possible to adapt the wiring for multiple buttons; bear with me:

On mbfm_din_default.pdf each martix column has it's own button. Nothing special here.

On mbfm_dout_default.pdf J4 - D5 goes to the R1 button and then to the R1/C1 LED, but also to the R1/C2, R1/C3, and R1/C4 LEDs. you need to press 2 buttons to create the necessary link for a function.

If I were to wire DOUT J4 - D5 not to 1 but to 4 buttons instead (daisy chained), assigning each button for a differen function of C1 and then wiring that button to the corresponding pin on the DIN module, pressing that one button would produce the necessary link between the shift registers!

Please correct me if I am wrong!

[NorthernLightX]

Necro bump! :hairy:

Change of plans completely; the enclosure will still be 1U, but the control will be limited to one encoder only (for selecting patches). The sound editing is much easier from a computer screen anyway. I am not saying TKs 2U interface lacks (I couldn't - I have never used it) but I don't want to make it a 2U box, and cramming all controls in 1U is not feasible.

I have most of the modules ready and wired up, an enclosure is in backorder and inquiries for a frontpanel have been made. With a bit of luck the box could be finished in a few weeks :angel:

[ytsestef]

Good Luck!

Just so you know, remapping the register pins is very easy. :)

[NorthernLightX]

remapping the register pins is very easy

Yes, remapping is. Adding functions and/or replacing the current matrix with the proposed matrix isn't, at least for me :). I also highly doubt I'll use the matrix I proposed, it was more a case of "because I can".

As soon as I have a proper case I'll see if I can cram some buttons under the LCD, for added fun.

[m00dawg]

To keep things simple for your 1U, you could use the sammichFM baseboard (if you can still find them) and then just bolt on your control surface. I am also building a 1U for my FM and SID synths (hopefully in the same 1U if I can), both using the Sammich baseboards, or so is the plan.

Given you're going for 1U, I am curious, how are you handling the buttons under the LCD? I found those to be a tight fit on a 1U panel :/ (haven't found a workable solution yet for that).

[NorthernLightX]

Problem is I already have a working Core and OPL board, so going for the Sammich baseboard would be a waste. I have measured everything to death, and there -should- be 6mm of space beneath the LCD; just enough to mount some buttons. I've just ordered the case, and will report back with pics if buttond under the LCD will work for a 1U case. If it fits I will go for the minimal CS, without the matrix. Instead I will use the frontpanel space for some external FX, I will report back with more details later :rolleyes:

[m00dawg]

Well, that OPL board might go to waste, but you can always use a CORE board for something :) Plus, Sammich already has the bank-sticks and a nice power solution. The latter is admittedly one thing that would have been nice to have a separate option for (I will already have bipolar power in my rack so I could have just provided that) since the solution ends up using low gain op-amps. But it does mean it's simpler all around, and you can always add more gain at a later stage if need be.

[NorthernLightX]

OK, I should have been more elaborate; I already have everything working except the CS. I have:

- Core8

- OPL3

- LTC

- 8x Bankstick

- LCD

- DINx4

- PSU that delivers +5 +12 and -12 (Mean Well)

I also already have a spare Core8 board so there's really no need for Sammich (I'll go for the cake instead :flowers: )

[m00dawg]

ah well if you already have everything working, not much else to do there then :) I still like the Sammich though from a space standpoint, but you have more banksticks and better power. These days I put my DIN/DOUTs on the CS boards themselves and chain them using headers. You might see if you have some spare room to do that, or perhaps mount another board behind the CS (as a sort of sammich) - that's my preferred method.

I was going to say that you only need one 74HC165, but I keep forgetting the MBFM "minimal" control surface has quite a few more buttons and so, for that, you might need a few. I'm debating on how much I really need since the idea is to control the synth with a DAW or, later on, an MBSEQ for setting up an arrangement (this is for live shows, so we won't be modifying patches frequently and don't really need much as a result). So I really just need enough buttons to be able to manually setup the instruments should the DAW or MBSEQ fail.

You might have already figured out what the true minimal surface is to do that - I haven't yet for the MBFM :)