Midibox based midicontroller for Traktor Pro

[Prodigy]

Hello all!

I am a newbie who is planning to build a midi controller for Traktor Pro. Well, I red a lot of information on the whole ucapps.de, but i have still some questions.

I would like to build a midi controller for Traktor Pro, with the next functionality:

- A stm-32 based core module

- Some rotary or sliding(faders) potmeters (quantity not determined yet)

- Some buttons with led-indication in it (idem)

- A few rotary encoders (idem)

- USB-connection with my laptop

And here are my questions:

1. How do i 'tell' (/program) the STM32 on which DIN-addresses my rotary encoders are located? Because these uses 2 digital inputs i red..

2. Does anybody have experience on controlling LED's (dig. out) with use of the led-feedback in Traktor Pro?

3. When i buy the STM-board in SmashTV's shop the bootloader is already programmed. But where can i find the (template) software for the STM32?

4. The USB-connection property reduces my choice to the STM32, doesn't it? The PIC does not support USB-connection, right?

Parts:

Rotary pot: I would like to have rotary potmeters like the DJM-800 has:

- 270 degrees

- small head (don't know the exact english word)

5. Does anybody know where to find this kind of knobs?

Fader pot : I would like to have 2 different kinds of faders:

1. A stiff/rough fader, to control pitch, fader travel 100mm (i think stiff/rough is the best for pitch control)

2. A fine fader to control deck-volume 80mm

6. Does anybody now where to find these faders?

Buttons : For the buttons i would like to have them with an LED in the button (also like DJM800). The LED is controller by Traktor Pro

indicating the state of that button.

7. Anybody know where to find these?

Thanx in advance!

[phunk]

Hi and welcome,

unfortunately i can not answer all of your questions, (since i am a serato user :p) but i try to do as best as i can.

3. When i buy the STM-board in SmashTV's shop the bootloader is already programmed. But where can i find the (template) software for the STM32?

The most important issue you should consider is that the software for Midibox64 resp. Midibox64e has not been

"officially" (means by TK) ported yet to the new core32. That means, if you want to build a MB64(e) with core32

you have to code the software yourself or find other members who are already doing so. Look here for applications already running

on core32 http://ucapps.de/mios32_download.html

But for a MB64(e) you dont necessarily need core32, it has been running very well on pic based hardware for years and has been built

a few hundred times (probably).

4. The USB-connection property reduces my choice to the STM32, doesn't it? The PIC does not support USB-connection, right?

USB to Midi is supported as well on PIC based hardware via the GM5 Modul.

Parts:

That very much depends on your location and the part suppliers in this region.

Search the forums first, there are many threads about faders, pots and suppliers.

ALPS makes pretty good faders and pots, relatively expensive though.

There are all kind of knobs from a lot of companies, depends on your supplier as well.

I once bought two original Pioneer rotary plates from a EFX500 directly at a pioneer

service to build some kind of XONE controller...

Edited May 20, 2010 by phunk

[Prodigy]

Hi and welcome,

unfortunately i can not answer all of your questions, (since i am a serato user :p) but i try to do as best as i can.

3. When i buy the STM-board in SmashTV's shop the bootloader is already programmed. But where can i find the (template) software for the STM32?

The most important issue you should consider is that the software for Midibox64 resp. Midibox64e has not been

"officially" (means by TK) ported yet to the new core32. That means, if you want to build a MB64(e) with core32

you have to code the software yourself or find other members who are already doing so. Look here for applications already running

on core32 http://ucapps.de/mios32_download.html

But for a MB64(e) you dont necessarily need core32, it has been running very well on pic based hardware for years and has been built

a few hundred times (probably).

4. The USB-connection property reduces my choice to the STM32, doesn't it? The PIC does not support USB-connection, right?

USB to Midi is supported as well on PIC based hardware via the GM5 Modul.

Parts:

That very much depends on your location and the part suppliers in this region.

Search the forums first, there are many threads about faders, pots and suppliers.

ALPS makes pretty good faders and pots, relatively expensive though.

There are all kind of knobs from a lot of companies, depends on your supplier as well.

I once bought two original Pioneer rotary plates from a EFX500 directly at a pioneer

service to build some kind of XONE controller...

He Punk, thx for your reply.

Considering your answers on the STM-32 core choice, i think i can better choose for the PIC8 based core, because this one is well supported by ucapps.

You are talking about the midibox64 and midibox64e, but what is the difference? Is there only difference in the software? Both are running on a PIC based core with several DIN and DOUT and AIN modules right?

Is it true that the midibox64 does NOT support rotary encoders, but the midibox64 does well?

About the controllers i asked questions about. I think i know a local dealer which i can visit, so i can see and Feel what kind of controllers i will buy :D...

[Fozzy The Bear]

You are talking about the midibox64 and midibox64e, but what is the difference?

Midibox 64E supports rotary encoders attached to DIN modules. In answer to your earlier question, the 64E supports 32 Rotary Encoders, because each encoder uses up 2 of the inputs on the DIN Modules. So for example 2 Din-X4 Modules will support either 32 Rotary Encoders OR 64 Push Buttons or a combination of the two devices that uses up no more than the 64 available inputs of the two boards. For example you could have 16 Rotary Encoders (32 inputs) and 32 Push Buttons (32 inputs) at the same time.

You can use four DIN X4 boards, and get 128 inputs, but you would need to do some software programming.

Midibox 64 does not have the support for rotary encoders, but does support up to 64 Pots via AIN Modules.

The number of inputs appears to be a software rather than a hardware limitation..... MIDIO128 has 128 DIN inputs but I believe that it sacrifices other available input types to achieve that.

And you're making the right choice, by using the earlier core modules right now. The software support for the new 32Bit core is going to be a while coming yet.

I strongly recommend that you read read and read some more... the answers to all the questions you asked are already in the documentation or the forum.

Best Regards,

Julian (Fozzy The Bear)

Edited May 20, 2010 by Fozzy The Bear

[findbuddha]

3. When i buy the STM-board in SmashTV's shop the bootloader is already programmed. But where can i find the (template) software for the STM32?

http://svnmios.midibox.org/listing.php?repname=svn.mios32&path=%2Ftrunk%2Fapps%2F

There's a tutorials folder. :)

[Fozzy The Bear]

http://svnmios.midibox.org/listing.php?repname=svn.mios32&path=%2Ftrunk%2Fapps%2F

There's a tutorials folder. :)

Yeah! and very good it is too..... He should also check out and read the WIKI WIKI LINK CLICK HERE

Best Regards,

Julian (Fozzy The Bear)

[Prodigy]

Thx guys, for the links to the tutorial and wiki. I red some info on the wiki, but i guess there is much more. The tutorial is for the sofware only i guess? Wether or not, i will check it out soon :).

Normally spoken i will do first things first, but considering the deliverytime of the coremodule (including pic) i would like to order this coremodule as soon as possible. But i have to specify the choice of PIC-uc and a header. Considering that i am going to create my midibox controller base on the 64e, i have to choose the PIC18F452, with header 0000 0000 0000 0000 (because i plan to use a normal LCD (16*2), and id doesn't care, because i use 1 core only) right?

[Fozzy The Bear]

and id doesn't care, because i use 1 core only) right?

Yes that's right.... as long as you remember that when you are uploading a program to the core that you will need to know the header that you chose.

It's OK to use the first core with all 0's in the header, if you later want to expand the design and add another core you just make the new core end in 01 and the next one end in 02 and the next 03 etc etc.....

Best Regards,

Julian (Fozzy The Bear)

[Prodigy]

Do the potentiometers really need to be 10k? I thought 100k or 1000k is OK too..

What are the (dis)advantages of a bigger/smaller resistance?

[Screaming_Rabbit]

What are the (dis)advantages of a bigger/smaller resistance?

Please use the forum search - You'll find plenty of topics regarding this.

Greets, Roger

[Prodigy]

Well, i searched the wiki, ucapps and the forum but not really a technical answer to my question. I think potentiometers with a bigger resistance are better because in that case there flows less current through the potentiometer. This will result in a smaller current consumption for the midicontroller.

I only need this statement to be confirmed by anybody...

[seppoman]

Well, i searched the wiki, ucapps and the forum but not really a technical answer to my question. I think potentiometers with a bigger resistance are better because in that case there flows less current through the potentiometer. This will result in a smaller current consumption for the midicontroller.

I only need this statement to be confirmed by anybody...

you're right that higher resistance will decrease the current consumption. But 100 pots/faders consume only about 50 mA, so compared to e.g. the LCD backlight where a little turn of the trimpot can change the current by +/- 100 or 200 mA, there isn't very much to be saved.

And there are reasons why TK specifies 10k pots and almost everyone including most commercial controllers use this value. The higher the resistance gets, the weaker the pot signal becomes. If you got only a very tiny compact box and take care of proper wiring, you might be able to use 50k or maybe even 100k pots. 1000k is definitely unusable. But even with 10k, there have been some people complaining about unstable and jittering values of pots. This is mostly caused by bad wiring or physical placement of e.g. a transformer/SMPS, but still 10k is a good compromise value that allows for stable readings in 99% of cases and doesn't use much current.

Let's say if I had a huge number of highest quality 20k or 50k pots laying on the cupboard, I'd probably try out if they work fine. But if you buy new ones, please just stick to the specification and save yourself (and us) the hassle of first troubleshooting and then replacing the pots anyway.

S

[Prodigy]

Thnx Shnizzle, great answer on my question, explaining everything. You are right by the current saving. It aint much compared to the current consumption of the lcd.

The reasing for asking is that i found some beautifull knobs on farnell.com, but only deliverable with 100k resistance.

Referring to your answer i can better search further for the same beautifull knobs, but with 10k resistance. ;)

[Wouter Brinkman]

The reasing for asking is that i found some beautifull knobs on farnell.com, but only deliverable with 100k resistance.

Referring to your answer i can better search further for the same beautifull knobs, but with 10k resistance. ;)

I was hunting for similar looking knobs, but my guess is that they're reserved for pioneer themselves. You could ofcourse buy official Pioneer knobs as spares ( http://www.chemical-records.co.uk/sc/search?must=pioneer+djm+800+knob&Type=&inandout=true&SRI=true&ND=-1 ) but they are well expensive.

Closest thing compared for a decent price are a bunch by Eagle Plastic Devices (parts 450-4011 and 450-4010 on mouser.com - also used in the Aurora Mixer), or try Neutrik/Rean knobs. I think some of the latter are used on other branded DJ mixers.

[Prodigy]

Last week i receiver the core pic module, including the pic PIC18F452 with bootloader. I soldered all parts on the module (except for the 2 isolated cables).

This afternoon i have installed the Developing Applications succesfully, and also succesfully build my own program, for test purposes..

After installing the mios studio i connected my laptop (sony vaio FW41EH, windows 7) with the pic-core-module using an USB-midi cable(/converter). I received messages from the pic every 2 secs, indicating a living pic :P

But after that i ran into the following problem:

When i select my usb-midi-cable by midi out and midi in in mios studio, the studio can not recognize my pic :S

But when i select my usb-midi-cable by midi in and another midi-device by midi out (for example a midi-yoke 'device') mios says 'bootloader is up and running' when i hit the query button.

Concluding this, it means that my pic is recognized only, when another midi-device is selected by the midi-out in mios-studio.

I have tested the midi-in and midi-out connection between my pc and the pic using the troubleshooting page, but everything seems to work fine.

Does anybody have any experience with this kind of problems, or does anybody have a solutions or hint to a solution?

[Prodigy]

Well guys, forget about my last post. I have come to the conclusion that the pic based core is not gonna work with my fresh new usb midi cable :(. I've tried it on another computer with a MIDI IN and MIDI OUT connection (so no USB-MIDI converter included) and it all worked well. It is possible to upload a new app to the controller with this computer, but not with my usb-midi cable :(.

My question at the moment is: Is an MIDI-IN and MIDI-OUT required on your computer, to use the midibox with? Or is it anyway possible with a usb-midi converter too?

Thx in advance

[Fozzy The Bear]

My question at the moment is: Is an MIDI-IN and MIDI-OUT required on your computer, to use the midibox with? Or is it anyway possible with a usb-midi converter too?

The answer is yes it is possible..... BUT! USB-MIDI converters don't all work the same way and some of the cheap ones off ebay have problems with lag and loss of data with bi-directional communication. Personally I think this has a lot to do with the original Microsoft Driver that they tend to use.

I know that the GM5 works because it works fine with my core. So the E-mu one should also work fine... As long as you're using the E-MU Xmidi driver for it and NOT the generic Microsoft driver. The E-MU Xmidi driver is available from: http://www.emu.com/support/files/download2.asp?Centric=1026&Legacy=0&Platform=1

E-mu say "While the Xmidi 1x1, Xmidi 1x1 Tab and Xmidi 2x2 are

true plug and play and will function as a MIDI device

using the included generic Microsoft MIDI drivers,

installing and using the E-Mu Xmidi driver will provide

improved MIDI latency, reduced MIDI jitter and multi

client MIDI application operation.

Tested to work in Windows XP, Windows Vista x32 & x64,

Windows 7 x32 & x64"

Simultaneous MIDI in and out are used by the core for a couple of things. Not least of which is to keep track of the position of rotary controls and pots and switches in the software running on the computer and keep the true (virtual) position of those updated in the midibox software... thus keeping your virtual and hardware interface controls in sync with each other. Although this is not actually essential in some applications. It really depends what you're doing with it.

It's certainly essential to have fully working Bi-Directional communication for programming MIDIBOX or it'll lose some of the data. It could easily be Latency and Jitter causing the problem.

Hope that helps!

Best Regards,

Julian (Fozzy The Bear)

Edited June 8, 2010 by Fozzy The Bear

[Prodigy]

Well guys, it has been a long time ago, but.. now i am finally finished with my midicontroller. The last functionality i want to build in, is touch sensitivity for my jogwheels. The requested hardware for this is already realised, but i have some questions about the software. According to this and this article it is possible to add touchsensors using J14 of the mainboard in combination with the DINX modules. But how can i activate this in the software? How can i determine wich pins of the DINX modules i use for touch sensing? How can i program the sensitivity?

I will post some recent photo's of my mixer later ;)..

Thx in advance

[julienvoirin]

C_DECLARATION void MIOS_SRIO_TS_SensitivitySet(unsigned char sensitivity)

DESCRIPTION sets the touch sensor sensitivity.

sensitivity == 0x00 disables the TS so that Pin RD.4 (J14 of the core module) won't be driven by MIOS anymore and therefore is free for other purposes

have a look in mios8 fonctions webpage

i am really very interested by your design as i discovered Traktor Scratch Pro a few times ago and it is still a revolution in my head :w00t: :w00t: