Building a MIDI 'keyboard' controller, microtonal

[theholyzero]

Would the process of assigning the ratios and variations of cents for each note be involved in the programming of the PIC?

also, just to confirm the case... note triggering would more likely be from DIN vs AIN right? Or perhaps either?

[SLP]

DIN is okay unless you want it to be velocity sensitive of aftertouch.

you can use the MB64 firmware. that's okay for the buttons and the pots.

BUT:

your midibox would send stuff like:

-note A4 on

-pot #24 turned to position 56

-note Bb2 on

-note A4 off

so you have to use a software on the PC that supports microtonal stuff.

software that goes like:

"Alright, note A4 is on and pot #24 is turned to position 56, so I have to make a sound with 430Hz instead of 440Hz (pot #24 would be at 64 then) "

[stryd_one]

DIN is okay unless you want it to be velocity sensitive of aftertouch.

True... Channel aftertouch (from an analog source) can be applied to a digital input though.

so you have to use a software on the PC that supports microtonal stuff.

Not necessarily... Some microtonal controllers send a calculated pitch bend right before each midi note out. Of course if you want to do that, then

you can use the MB64 firmware.

May not be true....

So tell us more THZ! I'm very curious :)

[SLP]

Some microtonal controllers send a calculated pitch bend right before each midi note out.

I've never seen such controllers... I didn't even know that they are actually existing

May not be true....

hmm... midicontroller, pots, buttons.... well, he could use the MB64E in case he'd prefer rotary encoders.

Do you have any other suggestions?  constructive criticism, please  ;)

[stryd_one]

Well if you want to do a mod of mb64(e) to send notes microtonally, you need to have a table/array/whatever, for each scale, which contains the note data (pitchbend change, some sysex, whatever you need to send to your synth). Then you would need to mod the function for sending the notes, to use that data.

I doubt that such a full-featured app as mb64 will leave sufficient free memory for such a task... Maybe you could import scales from bankstick to reduce it rather than storing every scale in ram.... But MB64 is a gutsy app and not so much room for improvement on the current PICs. You could cut other features out to make room, or you could port the app to a more capable PIC (4685/4620/etc), but either would require fairly solid knowledge of the app, and even if these things were unnecessary, certainly PIC ASM.

Hope that was more constructive :D

Hey THZ when you tell me what you're planning to do maybe you could mention if you have some programming experience?

[theholyzero]

Yes, I am truly a beginner with programming, though I have been researching this concept for quite a while and have been trying to figure out how to do this myself so I don't have to spend over $300 for a converter.

I want to have a dedicated tuning for my controller, since so many have asked. no need to change it if I only ever want just one. No need for pots. I figure that if I ever want another tuning, I'll just make another controller. The tuning I want is the 43-tone 11-limit designed by Harry Partch. I presume that I can tell the PIC to change the values for the MIDI note numbers, so instead of a chromatic scale, I assign the actual frequency value (ratio to note number 0).

[stryd_one]

Heya THZ.

I definitely think that you could do this for less than $300, but it will take some time, as you will need to learn to program in C. Remember, time is money: If your main aim is to save money, maybe you could invest some extra hours at work and use the overtime pay to buy a commercial offering - it will probably be cheaper when you count your hourly wage into how long it will take. Of course you will have a lot of advantages in doing it DIY - it will be fully customized to your requirements and you can always add new features later if you want to, and you will have actually, like, learned cool stuff :)

What are the sound sources you will use?

How do they implement playing notes in a microtonal scale?

Remember that a midi note is just a message with a number attached to it - what the synth does with that number, is up to the synth. When I send a middle A, that's note number 69, my synth will play 440Hz. You will still be sending note 69 when you hit A4. What your synth does with that, is up to the synth.

Some modern synths allow you to send frequency information as a sysex command (http://www.midi.org/about-midi/tuning.shtml) but most do not - in those cases you have to do something else, like sending PB data with the note - and even then, your synths must all be configured to adjust pitch in a predetermined fashion.

So what I'm trying to say is... forget about this midibox for a minute, think about your synths and what they need to receive in order to play these scales.

[theholyzero]

So, even if I chose not to go with microtonal, my idea of making a matrix grid of momentary (on)-off tactile buttons interfacing the core via a digital in... how does it tell the core to use note information for separate triggers? Is THAT something I need to have programmed into the PIC, relative to received digital input?

[theholyzero]

say, 126 buttons... 10.5 octaves... 4 DIN modules... would each of the DIN modules need to be separately coded to transmit a 1/4 of the series 0-126 note numbers?

Am I perceiving this correctly?

[stryd_one]

Yep that's right. If you have 126 buttons you would probably just send the same midi note number as your button number, so button 1 would be note 1, button 2 note 2, etc.

Of course you can make any button send any message that you want, including whatever data you need in order to use microtonal tunings.

Check out the C Interface page, especially the Sending MIDI events on button movements example and also the Functions Reference.

It's a little different when using a scanning matrix, but as the developer of the app, how exactly it is done, is up to you :)