MIDIbox for Traktor Scratch Pro

[Rien777]

Hey MIDIbox-Community,

my mate and I are about to build a MIDI controller for Traktor Scratch Pro and have already worked out which functions of TS should be controlled by it. Actually we thought that we could base our controller on the MIDIbox64 but it appeared that we'll need about 140 buttons, 25 potis and one encoder to fulfil our wishes. We also want to use the CORE32 module, mainly because of the onboard USB interface.

Is it possible to connect this amount of buttons to the core module by cascading an appropriate number of DIN modules? We've also looked through the user projects in the MIDIbox wiki but we didn't find any controller with so many buttons.

Is the presoldered chip on the CORE32 module available in SmashTV's shop also preburned so that the MIOS can be uploaded via USB?

Thanks for every answer on our questions and a big compliment to TK for creating such a great platform!!!

Rien777

[philetaylor]

Hi Welcome to the community!

Technically MIOS32 supports 128 digital inputs. It can handle 16 shift registers on the DIN chain, each one supports 8 digital inputs (each DIN module contains 4 SR's). It could support more but this hasn't been tested (AFAIK) and according to TK's comments in mios32_srio.h may require additional buffering due to the length of the SRIO chain.

Having said that, in the rgb_led_controller mios32_config.h file I noticed this comment:

// number of scanned SR registers on SRIO chain

// default value 16 (see mios32_srio.h)

// Knöpfli uses max. 256 DINs, that is 32. 

#define MIOS32_SRIO_NUM_SR 32

So I guess up to 32 SR's (256 DIN channels) could be supported!

The standard AINx4 (analogue module) supports up to 32 pots so only one would be required.

Yes the CORE32 from Smash comes pre-soldered and pre-loaded with the MIOS32 bootloader so MIOSStudio can be used to upload your application.

Cheers

Phil

[Rien777]

Hey Phil,

thanks for your answer!

Parts will be ordered the next few days. Since I also use this project as student research project, the university will order and pay them ;) There are just some problems with ordering the parts from SmashTV's shop but I hope they'll do it.

We've tried to figure it out ourselves, but at the moment we're uncertain about the overvoltage protection of the MIDIbox itself as well as the protection of the device connected to it (in our case the AudioBox of Traktor Scratch Pro which costs about 600€).

Rien

[stuartm]

Just for my education:

what are you doing with 140 buttons when controlling Traktor Scratch ?

My advice is just to take into account possibility/controllabilty versus usability (i.e. I recommend to use a lower number of knobs buttons I meant), before digging deep into a hardware solution.

Edited February 1, 2010 by stuartm

[Rien777]

Hi stuartm,

we don't want to have to use a mouse to control TS when having build the MIDIbox and as there are two decks with effects, loops, cues, the browser section and more functions that are needed, this amount of buttons is necessary. Of course we start with a smaller number but one by one we want to expand the MIDIbox until all functions are implemented - finishing it with the case.

Rien

[Rien777]

Hey community,

a big problem appeared ordering the Core32 module at SmashTV's shop:

Sorry for the delays, waiting for some incoming backordered parts has me a few weeks behind. Full refunds are available if you are tired of waiting, just let me know.

Best regards - SmashTV

After some mails with Smash it is clear that this delay concerns the Core32 module (which isn't his fault at all - just wanted to point this out). As I build the MIDIbox as a student research project, a prototype should be ready at the end of march (as there my semester ends as well).

There are two possibilities:

-I ask my docent to postpone the deadline of the project (what I'll do anyway) and/or

-someone of you has already a Core32 module that he/she doesn't need and would sell it to me (which would be more than great).

I hope somebody can help me out of my mess.

Best regards,

Rien

[hoxo]

Hi! I made a Traktor controller myself and I used 64 buttons, which I think is more than enough to control pretty much everything in Traktor (that's what modifiers are for, and with led lights to remind you what modifiers are on its very comfortable) . If you plan to use all 4 decks, I would recommend you to make something like 2x NI X1 My link and a mixer section. Try to minimize your designs and maximize peformance. Planing something carefuly is much better than doing it twice.

Good luck with your project!

[Rien777]

Hey hoxo,

thanks for your advice and gratz for your box - looks fine.

My mate and I began planning this controller in october last year and we have really thought a lot about which functions of TS we want to control. 100 and x buttons seem to be quite a lot, I know. For example, we don't want to control the loop-length with potis but with one button for each length so that we have direct access to each loop-length - which results in 11 buttons per deck (and as we use two decks: 22 in total). There are also some "extra wishes" that are not originally implemented in TS such as sorting the browserlist by title, artist or rating.

Rien

[Rien777]

Hey again,

at the moment, I'm about to solder the modules and to write the program for our TS controller. I'll also take some pictures of it when soldering is done and the modules are connected with each other - which leads me to my actual question:

Browsing the wiki and the documentation on ucapps.de, I read that the ports J16 and J19 basically are similar to J8/9 where the DOUT and DIN chains have to be connected. Is it possible to connect further DIN chains to J16/J19? If true, how big will the effort be to implement these changes?

We aren't in need of these ports as interfaces for SID/AOUT/SD or Ethernet modules - so why let them unused? ;)

Greets Rien

[philetaylor]

Hi.

J16 is (by default) also an SPI interface like J8/9 so technically there is no reason why it couldn't be used for a DIN/DOUT chain and achieve the same performance as with J8/9. J19 is a different case as it doesn't have a hardware SPI port behind it, SPI is achieved in software so the performance isn't as good as with the ports with hardware SPI (J8/9 and J16).

The code for DIN/DOUT (handled in mios32_srio.c) currently only supports a single port for this so it would be pretty easy to change "which" port the DIN/DOUT chains were connected to by redefining MIOS32_SRIO_SPI* but it would be a much more complex task to allow multiple DIN/DOUT chains and would likely involve rewriting mios32_srio.c.

Cheers

Phil

[Rien777]

Hey Phil,

thanks for your answer - exactly what I needed!

Then I temporary have to accept that I can't use more than 4 DIN modules for the controller. Maybe I'll do this work...anytime, but at the moment my studies absorb nearly my whole spare time.

Regards

Rien

[highpow3rpc]

Hey i would like to bump this thread to see how you guys are going with the project, i am trying to do something similar :) but am stuck with the software side of things i have no prior knowledge of programming if any one can help please pm me i would be very grateful, thanks in advance

[Rien777]

Hey,

at the moment, I am about to write the project report as I'm building the "prototype" of our box as student research project.

At this time, the modules are soldered (except the DOUT-modules), the part of the program is written which handles the buttons and a "test panel" with the Sparkfun buttons is build. The design of the front panel is also ready so far.

TODO:

• program the AIN & LED handler routines
  
• solder all Sparkfun PCBs
  
• define the MIDI hotkeys in TS
  
• order pots (also ones with momentary switch function)
  
• get a frontpanel
  

NOTE: If anybody has seen some pots with momentary switch function (like Alps RK117) PLEASE pm me! I've already spent a lot of time for searching for this type of pots.

cu Rien

Hey i would like to bump this thread to see how you guys are going with the project, i am trying to do something similar :) but am stuck with the software side of things i have no prior knowledge of programming if any one can help please pm me i would be very grateful, thanks in advance

[highpow3rpc]

Good luck with the box :) I hope to build something very similar to your controller, did you use any encoders or did use only pots and switches

good luck with the rest of the project and hope it works well :)

Thanks for the update.

If at all possible would I be able to see a copy of the code and then once its revised as I would like to learn from seeing the code in practice.

awesome project

Highpow3rpc

[Rien777]

Thanks! :)

I plan to upload some pictures of the soldered modules and the buttons - that's really all we have at the moment - but as the deadline for my report is this Thursday I spend all my time on finishing it. After this, more info will follow concerning the code etc.

We'll use one encoder to scroll the tracklist of Traktor Scratch and about 20 pots for effects etc. 16 of these pots should have a built-in momentary switch but we haven't found something like this - except the ALPS RK117. As I've only seen them at the ALPS homepage I don't know where to get them...

Rien777

PS: Wish you also good luck with your box :) keep us up-to-date ;)