DIY? Midi Control surface

ROBSCIX · Jul 18, 2004, 06:36 AM

I am sorry if it sounds like a noob question, don't know much about Midi though. The question is, I have noticed by looking through the Kx drivers that most things can be mapped to Midi, Surrounder....reverb..whatever. I like that Idea. Do people use control surfaces for such things? I would like to build one. I have electronics exp...and I am doing my research. I was just wondering if it has been done yet..probably. I am not talking about controlling some OSC, I mean controlling the parameters of the Kx driver. If anybody has done this or has links...docs, specs...to such info. I would greatly appreciate it.

Lex Nahumury · Jul 18, 2004, 12:04 PM

>>...I mean controlling the parameters of the Kx driver........

You can control all 'automated DSP-plugins parameters' via MIDI.
So if you build your external MIDI controller, just route that data to
the 'kX Control' MIDI port.

For example like this;
Your controller -> MIDI_IN -> MIDI OX -> 'kX Control' MIDI port

/LeMury

**dj_stick** · Jul 18, 2004, 01:12 PM

i myself was just thinking about buildign a midi control surface earlier today - it's an interesting idea - if you come up with anything let me know

ROBSCIX · Jul 18, 2004, 05:22 PM

Well, When I come up with something I will be posting links to schematics etc. I seem to only be able to find insturment type interfaces....not just a control surface. I will try and get the specs for the port and just start building from there. My college education was geared towards designing control electronics so I think I can manage it. I am just having a bit of a time finding the info I need. What do you think would be a resonable controller? I mean, use POTS Sliders...10-12-24-64 channel? I am really kind of siked about the project really. I will keep the forum posted..

Daniel Drummond · Jul 18, 2004, 08:34 PM

Here you go: http://www.ucapps.de/ Those midi controllers are awesome!!!

**dj_stick** · Jul 18, 2004, 10:32 PM

thanks for the link daniel - i remember reading that a while ago
but i am pretty sure m-audio or evolution have a dedicated control surface with pots on it…

ROBSCIX · Jul 18, 2004, 11:29 PM

That's what I was looking for..thank you. I remember stubling on that but I got side tracked....ok the project has begun. Does anyone have any suggestion as to what would bw nice to have incorporated. Like dedicated eq sliders....surrounder section. I am going to design this project for exclusive use with the KX project. With that in mind I will try and gear the control surface to this end.....ANy suggestions, Ideas, would be great. Definatley help speed up development.

I have been looking for a project to do in my spare time...I think I found it....

Daniel Drummond · Jul 19, 2004, 02:06 AM

Robscix, it'd be great if you could (based on uccaps site) design a specific kx oriented control board which could be built by other people as well (people who are not very skilled in electronics as myself). Good luck and let us know your experiences and achievements! Maybe integrating KX, Cubase and softsynths control in the same interface would be great...

ROBSCIX · Jul 19, 2004, 02:29 AM

Yeah thats what I was thinking. I would be more than happy to post my designs..etc. I would like to get some more input before I start doing Prototypes. When I stumbled on the MIDI automation section of KX I was like "Wow, I have to do something with this" I would like to get Kx users input as to what would be cool to have on the controller. Like would they like to be able to control the surounder sliders?, reverb..chorus amounts. Push buttons for speaker selection? Control the graphic/para EQ, Like this thing could be very cool. I am not sure if its possible to use automation to load different patches in the driver itself. I am getting very excited about this project. I am starting with the Kx controller because I love Kx. I am forever tweaking settings so I would like to have a nice looking interface for individual plugins within the driver...I would really appreciate IDEAS. like a LCD screen would be Cool but I am not sure yet if I will use it, for cost reasons. Come on guys this could be something that could be useful to ALL- let me hear what you think. I want to make a few different ones. I want to keep costs as low as possible so everybody who wants one could build one. As I said I AM VERY EXCITED about the possibilites, after I check your link..I pretty found all the info I need to build whatever I want. Thank you again.

Daniel Drummond · Jul 19, 2004, 02:52 AM

Just an idea: maybe you should start a new thread with a specific title about asking for suggestions.

ROBSCIX · Jul 19, 2004, 03:05 AM

Thats a good idea, should I put it in the general or in midi forum...

Daniel Drummond · Jul 19, 2004, 03:48 AM

General, to get more viewers.

TravelRec. · Jul 19, 2004, 07:00 AM

Quote:

Originally posted by Daniel Drummond
Robscix, it'd be great if you could (based on uccaps site) design a specific kx oriented control board which could be built by other people as well (people who are not very skilled in electronics as myself). Good luck and let us know your experiences and achievements! Maybe integrating KX, Cubase and softsynths control in the same interface would be great...

Yo!

Time to switch in

... I followed this thread a while and I also want to build such a controller box. But (I said it in general discussion, similar thread) I doubt this will be possible with some easy electronics, ´cause you need a bit processor power (or programmable logic) to generate the MIDI events. Your electronic must be able to react fast and only if any input on the controller pots or buttons appears. You also need A/D conversion to scan the pots or faders and finally you need some displays to see what you do. Not so easy as you may think - I think. But we will see what comes up. I think I´ll support this project as good as I can.

Greetings!

TravelRec.

Lex Nahumury · Jul 19, 2004, 01:34 PM

>>Your electronic must be able to react fast .....

TravelRec;
16 years ago (back when MIDI gear was realy expensive) I build a 'velocity sensitive 6 octave Midi Master keyboard' with 5 sliders, pitchbend and modulation pots just with one Z80 running at 4Mhz..!

With todays fast Micro controllers like PIC or ATMEL it's no problem at all.
One can easily scan ~+100 analog signals (pots etc) via multiplexing and still meet (and beat) the
'slow' Midi transmition rate.

ROBSCIX;
Just a tip; before you start bulding, it might be wise to check 'kX midi automation implementation'
via software applets that generates midi messages (there are lots of free ones).
Could save you a lot of time/trouble.

/LeMury

ROBSCIX · Jul 19, 2004, 02:59 PM

Travelrec, It is actually easier then you think, I thought it would be difficult also, but I am going to be using a PIC. I need a hobby project, this is it. I already have my basic schematics and designs; I just need some input as to what other people would like to see on the controller, I will be posting the project, witth all docementation.....it will kind of be my tribute to Kx. butI am not sure as to what you mean:

ROBSCIX;
Just a tip; before you start bulding, it might be wise to check 'kX midi automation implementation'
via software applets that generates midi messages (there are lots of free ones).
Could save you a lot of time/trouble.

Could you explain why I should try this?..

Lex Nahumury · Jul 19, 2004, 07:06 PM

>>Could you explain why I should try this?..

Well, you already can simulate/check/examine/determine all your 'hardware controller's functions'
in software without (and prior to) building or programming stuff.
kind of a free development tool.

/LeMury

ROBSCIX · Jul 19, 2004, 07:30 PM

Thank you for the advice, any recommedations for good ones? or any will do. as I said I knew about 0 about Midi, I am hitting the books like crazy now...lol I am on fire. I think I am going to start designing the interface later on today..I just have SOOOO many ideas...have to start narrowing it abit. Going to make a custom PCB, learned how to do that a while ago..start gathering components. I want a very cool front Panel...I don't seem to be getting very many suggestions though

I guess I just opened the Porject Last night though. I contacted a few of the DSP guys to see if they had any Ideas...so far thank you to whoever helped. I went from about 0 to 60 in a few mouse clicks....the hardest part is over. Thanks for your help...keep the suggestions coming.

dungle · Jul 20, 2004, 03:14 AM

Checkout Vmidibox link from midibox site.
It is a virtual Midibox64 and can emulate a hardware midibox onscreen.
This way you can get an idea of actual functionality before the reletively
arduous task of hardware realisation. (HW mistakes and changes are a lot more significant!)
Having built a midibox64, I can say it is very hard to fully envisage how the
control surface will interact with your DAW workflow. It is an interactive process, so be prepared
to go through a few prototype/redesign cycles.
Midibox is the most sophisticated, open ended and well supported DIY hardware midi community on the planet.
cheers

Daniel Drummond · Jul 20, 2004, 04:58 PM

By the way, you can get free PICs from the manufacturer if you say it's for testing or for designing a new electronic project (or if you are into electronics education area).

Daniel Drummond · Jul 20, 2004, 05:00 PM

Also, check this other midi diy projects on the net: http://www.geocities.com/JDPetkov/ and http://www.come.to/re_turn and http://www.geocities.com/tpe123/folk...ynthstick.html and finally http://www.spacetaxi.de/sf/toaster.html

TravelRec. · Jul 23, 2004, 08:03 AM

Hi ROBSCIX!

Slightly I understand... I heard and read about the PICs and similar components but unfortunately I´m not a programmer, but a solderer

. So I asked a programmer to make some things possible and he said something about CPLDs and he will give me some hints next time - so we will see. Your project seems to be advanced - so I´m happy if I can be a little part of it (maybe you ignore my message in general forum).

LeMury: I know, there are many little processors that can handle MIDI as well, I only meant that the electronic around must be able to handle some quick response and the device should only send MIDI messages if a controller value has changed - that´s not as easy as it sounds... for me...

Greetings and regards!

TravelRec.

Lex Nahumury · Jul 23, 2004, 09:42 AM

TravelRec,

>>I only meant that the electronic around must be able to handle some quick response..

An cheap average 8-bit a/d converter can easly convert multiple voltages within usec (micro seconds).
(We only need 0~127 range at most, so accuracy is also not crucial)
Now how fast can a human change the position of a pot or slider between two adjacent tresholds?
By the time you moved the pot, the MCU already took thousands of samples.

>>and the device should only send MIDI messages if a controller value has changed...

Just take a cheap potmeter, put it between +5V and GND, read the wiper's voltage,
scale it to 127, compare previous readout with current one,
if not equal->send midi, update previous value,...do next pot.
That's all. no special parts.

>> - that´s not as easy as it sounds... for me...

Realy; making a midi controller that only sends out midi is very simpel.
The electonics needed are not critical (maybe use brand parts for durability only),
and the circuitry is realy not complex.

Ofcourse, one has to program the MCU in assemblar, but compared to coding
a Windows application or a DSP effect, doing 8-bit MCU stuff is realy easy and fun to do.

Building a midi instrument however like a 'wind controller', 'bass stick' or 'ribbon controller'
is more complicated, but only due to the elektro-mechanical parts properties and construction.

Grussen,

/LeMury

**dj_stick** · Jul 23, 2004, 11:33 AM

this is really interestinf

btw "ribbon controller" i think this is what my music teacher wants to buiold for some reason

dungle · Jul 23, 2004, 06:12 PM

hi guys,
LeMury,you make valid points. Have you seen uCApps.de?
There exists an opensource codebase for midi controllers and instruments
including Real Time OS for low a cost ucontroller family.
This includes ready to go, flexible applications and configuration tools.
Why reinvent the wheel when you can make use of the huge developments
that others have made? There is heaps of scope for code writing and customisation
and expansion for your own particular needs/ideas.
So for anyone interested in DIY midicontrol surfaces, please have a thorough look at
uCapps.de and midibox.org before starting from scratch.
cheers

Lex Nahumury · Jul 23, 2004, 08:51 PM

>>Have you seen uCApps.de?
Yep,..they have grown alot in the past years. Lots of usefull info/stuff there.
Like you said; enough to make "all standard common" controllers.
( which isn't that hard when it comes to the 'Logic' part )

Personaly I'm more interested in alternative 'Human Interface' solutions for a Midi controller
other then pots, switches and sliders which are simply not enough to capture
all common human musical expression techniques.

Take a standard Pitchbend contol for example;
You can't jump to a certain value whitout passing through all the adjacent values
and then glide back again.
A Ribbon controller, however, can! Adding more expression possabilities.
Unfortunatly, info and availability of such alternative elektro-mechanical parts are hard to find.

Well, enough of this (personal) discourse since the topic was about a "standard midi controller"

/LeMury

ROBSCIX · Jul 23, 2004, 10:20 PM

No, Don't stop, I like the off topic suggestions..helps development. I don't know if I would call this project a standard controller or not. I am envisioning more of an effects front end maybe for guitar or synth....then again there are so many possibilities. This is why I am asking for input. I am considering adding an expression pedal, as well as a floor board to change patches and paramters...have to be careful the design doesn't get away from me though

as was stated the logic is easy enough, the question is how am I goin to setup the functionality, I mean this is for that...etc. That's why I like the input from the forum. Helps with development. Hopfully this will be a project that alot of forum members will be interested in as some of their own ideas have been incorperated in one way or another..thanks for the suggestions and advice guys, keep it coming. I was putting together basic schematics today to give me an idea of PCB size, component list etc.....

dungle · Jul 24, 2004, 02:26 AM

LeMury, using the midibox MIOS platforms it is possible to configure custom events and interactions between events to whatever analog input transducer or digital rotatry encoder or even motor fader you want. It is an ideal springboard to realising whatever
instrument/expressive controller you dream of.
For engineering minded musicians the technical side of such systems is,(as you point out), quite simple. The practical realisation however, is always time consuming. It is difficult to divert one's attention to creating support tools that enhance ones efforts.
The midibox projects consist of ready-to-go hardware and software designs as well as frameworks or skeletons to make totally custom units.
ROBSCIX, I suggest you give midibox site and forum a thorough inspection as everything you mention has been implemented in various forms. What I think is required for your idea is to focus on what elements of kX you want to control and how.
My impression is that everything you want to do could be done with one of the existing midibox configurations using a custion hardware layout for your control surface.
cheers

Lex Nahumury · Jul 24, 2004, 04:31 AM

>>The midibox projects consist of ready-to-go hardware and software designs as well as
>>frameworks or skeletons to make totally custom units.

Yep, I fully agree with you. It's a real timesaver as you pointed out.
What I merely trying to state, is that in developing a Midi controller, or better, a Midi Instrument,
the pure (logic) electronics and software are never the "limiting" factors.
Their relative cheap, replacable, changeable etc. etc.

The construction and functionality of the mechanical parts acting as a proper Human Interface
however poses much more barriers.
Ever treid to make a Midi guitar/bass stick that realy played well?
Even when building a relative "simple" Midi drum pad, the construction of the mechanical Pad/transducer assembly takes much more effort then the electronics.
At least if you don't want to hit on the back of a beer can or cookie jar

/LeMury

ROBSCIX · Jul 24, 2004, 04:12 PM

Yes, I know it's been implemented in various places. I think I can pull it off. I can build the circuits in my sleep..lol. That midibox site is great. I just never thought it was that easy. Try to find the specification for midi i/o was painstaking...after I found that site though..it's all coming together now. Don't worry..lol I am doing my homework. I don't start projects until I know whats involved..start to finish..thanks for the advice.

Jul 18, 2004, 06:36 AM	#1
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	DIY? Midi Control surface I am sorry if it sounds like a noob question, don't know much about Midi though. The question is, I have noticed by looking through the Kx drivers that most things can be mapped to Midi, Surrounder....reverb..whatever. I like that Idea. Do people use control surfaces for such things? I would like to build one. I have electronics exp...and I am doing my research. I was just wondering if it has been done yet..probably. I am not talking about controlling some OSC, I mean controlling the parameters of the Kx driver. If anybody has done this or has links...docs, specs...to such info. I would greatly appreciate it.

Jul 18, 2004, 08:34 PM	#5
Daniel Drummond DriverHeaven Senior Member Join Date: Dec 2002 Location: Brazil Posts: 1,137 Rep Power: 0	Here you go: http://www.ucapps.de/ Those midi controllers are awesome!!! __________________ www.palcomp3.com.br/ed

Jul 19, 2004, 02:06 AM	#8
Daniel Drummond DriverHeaven Senior Member Join Date: Dec 2002 Location: Brazil Posts: 1,137 Rep Power: 0	Robscix, it'd be great if you could (based on uccaps site) design a specific kx oriented control board which could be built by other people as well (people who are not very skilled in electronics as myself). Good luck and let us know your experiences and achievements! Maybe integrating KX, Cubase and softsynths control in the same interface would be great... __________________ www.palcomp3.com.br/ed

Jul 19, 2004, 02:52 AM	#10
Daniel Drummond DriverHeaven Senior Member Join Date: Dec 2002 Location: Brazil Posts: 1,137 Rep Power: 0	Just an idea: maybe you should start a new thread with a specific title about asking for suggestions. __________________ www.palcomp3.com.br/ed

Jul 19, 2004, 03:48 AM	#12
Daniel Drummond DriverHeaven Senior Member Join Date: Dec 2002 Location: Brazil Posts: 1,137 Rep Power: 0	General, to get more viewers. __________________ www.palcomp3.com.br/ed

Jul 18, 2004, 12:04 PM	#2
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	>>...I mean controlling the parameters of the Kx driver........ You can control all 'automated DSP-plugins parameters' via MIDI. So if you build your external MIDI controller, just route that data to the 'kX Control' MIDI port. For example like this; Your controller -> MIDI_IN -> MIDI OX -> 'kX Control' MIDI port /LeMury

Jul 18, 2004, 05:22 PM	Thread Starter #4
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Well, When I come up with something I will be posting links to schematics etc. I seem to only be able to find insturment type interfaces....not just a control surface. I will try and get the specs for the port and just start building from there. My college education was geared towards designing control electronics so I think I can manage it. I am just having a bit of a time finding the info I need. What do you think would be a resonable controller? I mean, use POTS Sliders...10-12-24-64 channel? I am really kind of siked about the project really. I will keep the forum posted..

Jul 18, 2004, 11:29 PM	Thread Starter #7
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	That's what I was looking for..thank you. I remember stubling on that but I got side tracked....ok the project has begun. Does anyone have any suggestion as to what would bw nice to have incorporated. Like dedicated eq sliders....surrounder section. I am going to design this project for exclusive use with the KX project. With that in mind I will try and gear the control surface to this end.....ANy suggestions, Ideas, would be great. Definatley help speed up development. I have been looking for a project to do in my spare time...I think I found it....

Jul 19, 2004, 02:29 AM	Thread Starter #9
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Yeah thats what I was thinking. I would be more than happy to post my designs..etc. I would like to get some more input before I start doing Prototypes. When I stumbled on the MIDI automation section of KX I was like "Wow, I have to do something with this" I would like to get Kx users input as to what would be cool to have on the controller. Like would they like to be able to control the surounder sliders?, reverb..chorus amounts. Push buttons for speaker selection? Control the graphic/para EQ, Like this thing could be very cool. I am not sure if its possible to use automation to load different patches in the driver itself. I am getting very excited about this project. I am starting with the Kx controller because I love Kx. I am forever tweaking settings so I would like to have a nice looking interface for individual plugins within the driver...I would really appreciate IDEAS. like a LCD screen would be Cool but I am not sure yet if I will use it, for cost reasons. Come on guys this could be something that could be useful to ALL- let me hear what you think. I want to make a few different ones. I want to keep costs as low as possible so everybody who wants one could build one. As I said I AM VERY EXCITED about the possibilites, after I check your link..I pretty found all the info I need to build whatever I want. Thank you again.

Jul 19, 2004, 03:05 AM	Thread Starter #11
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Thats a good idea, should I put it in the general or in midi forum...

Jul 19, 2004, 01:34 PM	#14
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	>>Your electronic must be able to react fast ..... TravelRec; 16 years ago (back when MIDI gear was realy expensive) I build a 'velocity sensitive 6 octave Midi Master keyboard' with 5 sliders, pitchbend and modulation pots just with one Z80 running at 4Mhz..! With todays fast Micro controllers like PIC or ATMEL it's no problem at all. One can easily scan ~+100 analog signals (pots etc) via multiplexing and still meet (and beat) the 'slow' Midi transmition rate. ROBSCIX; Just a tip; before you start bulding, it might be wise to check 'kX midi automation implementation' via software applets that generates midi messages (there are lots of free ones). Could save you a lot of time/trouble. /LeMury

Jul 19, 2004, 02:59 PM	Thread Starter #15
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Travelrec, It is actually easier then you think, I thought it would be difficult also, but I am going to be using a PIC. I need a hobby project, this is it. I already have my basic schematics and designs; I just need some input as to what other people would like to see on the controller, I will be posting the project, witth all docementation.....it will kind of be my tribute to Kx. butI am not sure as to what you mean: ROBSCIX; Just a tip; before you start bulding, it might be wise to check 'kX midi automation implementation' via software applets that generates midi messages (there are lots of free ones). Could save you a lot of time/trouble. Could you explain why I should try this?..

Jul 19, 2004, 07:06 PM	#16
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	>>Could you explain why I should try this?.. Well, you already can simulate/check/examine/determine all your 'hardware controller's functions' in software without (and prior to) building or programming stuff. kind of a free development tool. /LeMury

Jul 19, 2004, 07:30 PM	Thread Starter #17
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Thank you for the advice, any recommedations for good ones? or any will do. as I said I knew about 0 about Midi, I am hitting the books like crazy now...lol I am on fire. I think I am going to start designing the interface later on today..I just have SOOOO many ideas...have to start narrowing it abit. Going to make a custom PCB, learned how to do that a while ago..start gathering components. I want a very cool front Panel...I don't seem to be getting very many suggestions though I guess I just opened the Porject Last night though. I contacted a few of the DSP guys to see if they had any Ideas...so far thank you to whoever helped. I went from about 0 to 60 in a few mouse clicks....the hardest part is over. Thanks for your help...keep the suggestions coming.

Jul 20, 2004, 03:14 AM	#18
dungle DriverHeaven Lover Join Date: Dec 2002 Posts: 120 Rep Power: 0	Checkout Vmidibox link from midibox site. It is a virtual Midibox64 and can emulate a hardware midibox onscreen. This way you can get an idea of actual functionality before the reletively arduous task of hardware realisation. (HW mistakes and changes are a lot more significant!) Having built a midibox64, I can say it is very hard to fully envisage how the control surface will interact with your DAW workflow. It is an interactive process, so be prepared to go through a few prototype/redesign cycles. Midibox is the most sophisticated, open ended and well supported DIY hardware midi community on the planet. cheers

Jul 20, 2004, 04:58 PM	#19
Daniel Drummond DriverHeaven Senior Member Join Date: Dec 2002 Location: Brazil Posts: 1,137 Rep Power: 0	By the way, you can get free PICs from the manufacturer if you say it's for testing or for designing a new electronic project (or if you are into electronics education area). __________________ www.palcomp3.com.br/ed

Jul 20, 2004, 05:00 PM	#20
Daniel Drummond DriverHeaven Senior Member Join Date: Dec 2002 Location: Brazil Posts: 1,137 Rep Power: 0	Also, check this other midi diy projects on the net: http://www.geocities.com/JDPetkov/ and http://www.come.to/re_turn and http://www.geocities.com/tpe123/folk...ynthstick.html and finally http://www.spacetaxi.de/sf/toaster.html __________________ www.palcomp3.com.br/ed

Jul 23, 2004, 08:03 AM	#21
TravelRec. Alternative Audioproductions Join Date: Sep 2003 Location: Germany / Sachsen-Anhalt Posts: 1,710 Rep Power: 0	Hi ROBSCIX! Slightly I understand... I heard and read about the PICs and similar components but unfortunately I´m not a programmer, but a solderer . So I asked a programmer to make some things possible and he said something about CPLDs and he will give me some hints next time - so we will see. Your project seems to be advanced - so I´m happy if I can be a little part of it (maybe you ignore my message in general forum). LeMury: I know, there are many little processors that can handle MIDI as well, I only meant that the electronic around must be able to handle some quick response and the device should only send MIDI messages if a controller value has changed - that´s not as easy as it sounds... for me... Greetings and regards! TravelRec. __________________ Always take a look behind.

Jul 23, 2004, 09:42 AM	#22
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	TravelRec, >>I only meant that the electronic around must be able to handle some quick response.. An cheap average 8-bit a/d converter can easly convert multiple voltages within usec (micro seconds). (We only need 0~127 range at most, so accuracy is also not crucial) Now how fast can a human change the position of a pot or slider between two adjacent tresholds? By the time you moved the pot, the MCU already took thousands of samples. >>and the device should only send MIDI messages if a controller value has changed... Just take a cheap potmeter, put it between +5V and GND, read the wiper's voltage, scale it to 127, compare previous readout with current one, if not equal->send midi, update previous value,...do next pot. That's all. no special parts. >> - that´s not as easy as it sounds... for me... Realy; making a midi controller that only sends out midi is very simpel. The electonics needed are not critical (maybe use brand parts for durability only), and the circuitry is realy not complex. Ofcourse, one has to program the MCU in assemblar, but compared to coding a Windows application or a DSP effect, doing 8-bit MCU stuff is realy easy and fun to do. Building a midi instrument however like a 'wind controller', 'bass stick' or 'ribbon controller' is more complicated, but only due to the elektro-mechanical parts properties and construction. Grussen, /LeMury

Jul 23, 2004, 06:12 PM	#24
dungle DriverHeaven Lover Join Date: Dec 2002 Posts: 120 Rep Power: 0	hi guys, LeMury,you make valid points. Have you seen uCApps.de? There exists an opensource codebase for midi controllers and instruments including Real Time OS for low a cost ucontroller family. This includes ready to go, flexible applications and configuration tools. Why reinvent the wheel when you can make use of the huge developments that others have made? There is heaps of scope for code writing and customisation and expansion for your own particular needs/ideas. So for anyone interested in DIY midicontrol surfaces, please have a thorough look at uCapps.de and midibox.org before starting from scratch. cheers

Jul 23, 2004, 08:51 PM	#25
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	>>Have you seen uCApps.de? Yep,..they have grown alot in the past years. Lots of usefull info/stuff there. Like you said; enough to make "all standard common" controllers. ( which isn't that hard when it comes to the 'Logic' part ) Personaly I'm more interested in alternative 'Human Interface' solutions for a Midi controller other then pots, switches and sliders which are simply not enough to capture all common human musical expression techniques. Take a standard Pitchbend contol for example; You can't jump to a certain value whitout passing through all the adjacent values and then glide back again. A Ribbon controller, however, can! Adding more expression possabilities. Unfortunatly, info and availability of such alternative elektro-mechanical parts are hard to find. Well, enough of this (personal) discourse since the topic was about a "standard midi controller" /LeMury

Jul 23, 2004, 10:20 PM	Thread Starter #26
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	No, Don't stop, I like the off topic suggestions..helps development. I don't know if I would call this project a standard controller or not. I am envisioning more of an effects front end maybe for guitar or synth....then again there are so many possibilities. This is why I am asking for input. I am considering adding an expression pedal, as well as a floor board to change patches and paramters...have to be careful the design doesn't get away from me though as was stated the logic is easy enough, the question is how am I goin to setup the functionality, I mean this is for that...etc. That's why I like the input from the forum. Helps with development. Hopfully this will be a project that alot of forum members will be interested in as some of their own ideas have been incorperated in one way or another..thanks for the suggestions and advice guys, keep it coming. I was putting together basic schematics today to give me an idea of PCB size, component list etc.....

Jul 24, 2004, 02:26 AM	#27
dungle DriverHeaven Lover Join Date: Dec 2002 Posts: 120 Rep Power: 0	LeMury, using the midibox MIOS platforms it is possible to configure custom events and interactions between events to whatever analog input transducer or digital rotatry encoder or even motor fader you want. It is an ideal springboard to realising whatever instrument/expressive controller you dream of. For engineering minded musicians the technical side of such systems is,(as you point out), quite simple. The practical realisation however, is always time consuming. It is difficult to divert one's attention to creating support tools that enhance ones efforts. The midibox projects consist of ready-to-go hardware and software designs as well as frameworks or skeletons to make totally custom units. ROBSCIX, I suggest you give midibox site and forum a thorough inspection as everything you mention has been implemented in various forms. What I think is required for your idea is to focus on what elements of kX you want to control and how. My impression is that everything you want to do could be done with one of the existing midibox configurations using a custion hardware layout for your control surface. cheers

Jul 24, 2004, 04:31 AM	#28
Lex Nahumury DH Senior Member Join Date: Jan 2003 Location: The Netherlands Posts: 1,932 Rep Power: 64	>>The midibox projects consist of ready-to-go hardware and software designs as well as >>frameworks or skeletons to make totally custom units. Yep, I fully agree with you. It's a real timesaver as you pointed out. What I merely trying to state, is that in developing a Midi controller, or better, a Midi Instrument, the pure (logic) electronics and software are never the "limiting" factors. Their relative cheap, replacable, changeable etc. etc. The construction and functionality of the mechanical parts acting as a proper Human Interface however poses much more barriers. Ever treid to make a Midi guitar/bass stick that realy played well? Even when building a relative "simple" Midi drum pad, the construction of the mechanical Pad/transducer assembly takes much more effort then the electronics. At least if you don't want to hit on the back of a beer can or cookie jar /LeMury Last edited by LeMury; Jul 24, 2004 at 05:20 PM.

Jul 24, 2004, 04:12 PM	Thread Starter #29
ROBSCIX DriverHeaven Senior Member Join Date: Mar 2004 Posts: 1,732 Rep Power: 0	Yes, I know it's been implemented in various places. I think I can pull it off. I can build the circuits in my sleep..lol. That midibox site is great. I just never thought it was that easy. Try to find the specification for midi i/o was painstaking...after I found that site though..it's all coming together now. Don't worry..lol I am doing my homework. I don't start projects until I know whats involved..start to finish..thanks for the advice.