PICMIX - DIY midi DJ controller

[DJDoubleYou]

Ok I'll see what I can do about that :-) If the prototype works I'll draw some schematics. I'll make a PCB out of it, no problem to share it.

You're the best!

[Skirmitt]

I was wondering, what do most controller send out on a button press ? Do they send an on press message and an on release message ? What do you guys prefer, play on release or press ?

[zestoi]

I was wondering, what do most controller send out on a button press ? Do they send an on press message and an on release message ? What do you guys prefer, play on release or press ?

most controllers will send out a note-on on press (often just 0x7f if non velocity sensitive) and a note-off (often with a velocity of 64 which i still find odd) on release, tho sometimes just another note-on with zero velocity. controllers will almost always send out cc's for faders and encoders instead of notes tho in reality it makes no real odds whether notes or cc's are used ofc for dj type controllers.

you definately want to send out a message when the buttons are pressed and if you don't also send out a message on release then the buttons can't be mapped to "hold" type controls. i.e: can only be used for triggers or toggles.

the lpd8 in PC mode is like that as it only sends out a PC message when u press a pad - tho PC messages only need 2 bytes. makes the PC mode not so useful anyway, even when they're translated into notes or cc's.

the shorter answer to your question is "play on press"

[Skirmitt]

Thanks for your answer !! The reason I asked is cause the Numark Total Control I looked at from my friend is sending the note on on release so the track starts playing on release. You could think of releasing a record to make it play, though I don't think it is logical for a controller.

I do send CC for a fader and pitch bend for the pitch fader. As for the buttons I now send only a note on with value 0 and 127. Example:

newd0 = input(pin_d0);
if(oldd0 != newd0)
{
   if(newd0)midiout(150,40,127);
   else midiout(150,40,0);
}

Still have to find a page that informs me about all the possible midi messages and their range.

[zestoi]

Thanks for your answer !! The reason I asked is cause the Numark Total Control I looked at from my friend is sending the note on on release so the track starts playing on release. You could think of releasing a record to make it play, though I don't think it is logical for a controller.

I do send CC for a fader and pitch bend for the pitch fader. As for the buttons I now send only a note on with value 0 and 127. Example:

newd0 = input(pin_d0);
if(oldd0 != newd0)
{
   if(newd0)midiout(150,40,127);
   else midiout(150,40,0);
}

Still have to find a page that informs me about all the possible midi messages and their range.

odd re: the total control, even if it was sending out a noteon with zero velocity on release i'd still expect it to send out a non zero velocity noteon message on press. maybe due to some custom setup app?

this is the url i usually refer to for basic midi spec info: http://www.midi.org/techspecs/midimessages.php

your code seems sensible. no real need to send an actual noteoff message on release. internally in midimasher i just translate all noteon and noteoff messages into 'note' message for callbacks to attach to. only really makes any difference if you want to control an actual synth, where u need to send a noteoff message else the next noteon won't retrigger the ADSR envelope.

[zestoi]

any reason you're sending on midi channel 7? each midi port can send data on each of the 16 midi channels without getting mixed up with a different controller etc. i only ever used to care about midi channels when i was chaining synths via old school din-style midi cables using the midi-thru ports.

[Skirmitt]

The reason I'm sending on that particular channel is cause I didn't have a good midi message reference, I do now with that page you gave me, thanks a lot for that.

Changing all midi messages to something that makes sense was on top of my to do list. Must be something weird then with that Numark controller :-)

Sending a note off message might only be usable for cueplay actions where you hold the button indeed. You're right about that. I hope to finish the PCB and basic form of the code this week so I can do some testing with it.

I heard of Midimasher before a lot, what does it do exactly ?

[zestoi]

The reason I'm sending on that particular channel is cause I didn't have a good midi message reference, I do now with that page you gave me, thanks a lot for that.

good point i only started to get back into midi stuff a few months ago. i keep having to refer back to that webpage. it's pretty handy.

I hope to finish the PCB
and basic form of the code this week so I can do some testing with it.

cool. pretty impressive building your own controller and coding it too

I heard of Midimasher before a lot, what does it do exactly ?

sort of like bomes meets midikatapult and automap i guess? or something like that...

i wanted an app that would connect to all my controllers (and to traktor via one massive tsi and some virtual midiports) and route data any which way i wanted. the core is C++ (bad C++, more just C really) and implements any number of virtual layers for any controller with full led recall, handles reading the data and passing it onto user defined callbacks (coded in LUA) when needed.

i was afraid of latency issues using LUA but it seems fine. hadn't even heard of LUA until using it, but it seems ideal for what i need and embedible.

here for example is my attempt at recreating the slicer that the twitch/itch has in midimasher http://midimasher.djism.com/lua/lib/slicer.lua

quick code example, this will make a launchpad led flash to the beatphase in traktor:

capture("traktor", "heartbeat_a", ALL, 0, function(d, e, v, p)
  print("beat "..v)
  if v > 0 then
    send("lp", "0,0", 1, lp_yellow)
  else
    send("lp", "0,0", 1, lp_black)
  end
end)

and i have functions that build on stuff like that to create virtual faders on a launchpad or emulate a 4banks midifighter etc etc... LUA is cool in that it allows u to create functions kind of like javascript or perl that u can pass to other functions. in fact saying "function foo() end" is actually only syntactic sugar for "local foo = function() end"

[Skirmitt]

Impressive what you've made. I always think that the best solutions come from people that build it for theirself with only the end result in mind
Such projects have passion.

[Skirmitt]

The mapping for Traktor is complete after I've cleaned up my code with the help of the page that zestoi gave me.
Now I've drawn the jog wheels. These will be 90mm in diameter. The base is 2 layers of MDF and a perspex top. The perspex top will make it possible to use some sort of skins between the MDF and the perspex. I hope all fits well, fingers crossed. The parts will be laser cut.

Also made an MDF case for it, glue is drying at the moment.

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Another question, how can you map the cue(play?) button in Traktor so that it plays if I press it and stop if I release it ?