Some startup help wanted, regarding a small midi box

Design Concepts
1

Hello community,

This will be my first midi-project, and would like it if some people can guide me around a little.

I’am a student on the HKU(arts academy Utrecht, the netherlands) for a next project i would like to build a midi-box for controlling a VisualArtists program written in MAX/MSP.

The midi-box will allow for users(other than the vj) to make small changes to the visuals, live!

The overall design of the box will look as followed:

3 rotary encoders that will control a value from 0-127 or maybe limeted to only 0-100

3 led-displays for the user to see what the value of each encoder is.

See drawing:

I’have snooped around on the website and the rest of what google offers me. And made a preliminairy design of what i think should be the hardware of the box. I understand that once the hardware is finished, the race is not over and i have to start looking at MIOS etc. But thats for later.

In short

the device should give:

  • three times a value of 0-127 to the software

  • The actual value should be displayed for the user

  • connecting via usb to mac

As far as i can gather i need a core module, 2x a doutx4, a dinx4, rotary encoders and 7-digit led displays.

I made up a electrical diagram.

ps the midi to usb is an external

I’am completly new with this kind of electronics so i was hoping someone could give me some feedback on the design i made and/or if im going the right path.

Is it ordering time already?

hope to hear from someone soon

Thanx you very much

Ivo

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2

Hi … and welcome on board.

You are on the right way.

As far as i can gather i need a core module, 2x a doutx4, a dinx4, rotary encoders and 7-digit led displays.

I made up a electrical diagram.

Looking on your diagram just a few thoughts:

  • You won’t need a DINX4 for just 3 Encoders. A single DINX (only one IC) is also suitable (you just need 6 ports for  three encoders)

  • You won’t need a DOUTX4 for 9 led digits . You just need three DOUT (3 ICs). For the digits take a look here : http://www.ucapps.de/midibox_lc/midibox_lc_leddigits.pdf

Of course, if you order premade pcbs you have to take the 4x items. But if you handwire the circuit or if you build the pcbs yourself you can save some parts.

Thats the hardware.

I understand that once the hardware is finished, the race is not over and i have to start looking at MIOS etc. But thats for later.

Yep!  ;D

Is it ordering time already?

I think so. ::slight_smile:

greets

Doc

3

I understand that once the hardware is finished, the race is not over and i have to start looking at MIOS etc. But thats for later.

I’d say you’ve got that backwards… If you design the hardware first, and then have trouble making MIOS work with it, you’ll be in trouble.

As it stands, I think you’ll be OK, but I thought I should point that out…

4

thank you Doc and stryd_one,

Thank you guys for the fast reply.

Saving the experiment for now on the pcb’s and think i will get the premade ones (means the 4x) thank you for that.

I will start ordering and building the hardware.

Stryd i understand that the software is going to be a big job, but without the hardware there is nothing to test. Plus programming is logic, maybe not easy but its logic.

I have seen lots of good topics on the different mios issue’s etc, and are impressed by the way everyone is helping eachother out here. never seen such a community. Santé

Thank you and hope i will bring you guys good news in the future.

Ivo22

5

Ivo, I think it would be better to make the PCB’s yourself, there must be some people that can do that for you among friends or even at your school… Saves lots of money, and perhaps you can draw some custom boards so that you can stuff the encoders on a PCB instead making a cable mess.

Geloof me, een collega van mij kan ook PCB’s maken, en dat werkt een stuk beter dan bestellen uit de VS enzo.. Kost veel te veel!

6

Hmmm,

alright well you start to let me think about it now.

i would not start a cable mess, that is hopeless.

it’s not so hard to do myself, i can make the drawings easy, and i think some people at school indeed have made some before.

I’ll ask around

But i will still have to order the core-module anyway

(germany i was thinking shorter distance saves fuel)

Thank you Sinnsyk

goed idee zeg 1 bord niks draadjes!