I wish I knew more about hacking, but something like that on the nebulophone shouldn't be hard.  It's got connections for an arduino specifically set aside for hackers on the board.  Let us know if you figure something out.

oops - didn't catch the transpose mode...  i guess i should have rtfm.  But still - i'd like it to be a different key when booting up so i'll have to try changing that keyoffset integer.

I think you can already do what you're asking for.
From the manual:
Shift Button
"By default the keyboard is setup in D major like this : C♯2 D2, E2, F♯2, G2, A3, B3, C♯3, D3, E3 The D scale starts on the second key and ends on the ninth from the left. Pushing the shift button steps through five octave ranges: Low (D2 scale) » Med Low (default) (D3) » Medium default (D4) » High (D5)"

Transpose Mode
"By holding the shift button for 3 seconds you can enter the transpose mode. Once activated the LFO LED will go to full brightness, the ARP LED will dim and the LFO knob will control the key and temperament. All the way left – Chromatic tuning. Each key is a half step apart. Left half – Sweeps through major scale roots to set the keyboard to.
Right Half - Sweeps through minor scales.
Press Shift again the go back to normal operation"

Also youve messed with the transpose mode right?

oh, there is also this:

int keyoffset=0;

try changing that value.  it should shift it up one with a 1 value, up 2 half steps with a 2 value, etc...

not sure if you can transpose down with a -1, etc...  worth a shot!

};
int scale[]={
0,2,4,5,7,9,11,12,14,16,17,19,21,23,24,26,28,29,31,33,35,36,38,40,41,43,45,47,48,50,52,53,55,57,59,60,62,64
};

those are your whole/half steps.  whole-whole-half-whole-whole-whole-half (standard scale progression).  your base note i guess must be a C# (guessing that's the '0''s freq.)

so, if you wanted to change it to, for instance, all half steps: 0,1,2,3,4,5,6,7,8,9,10,...,n

unless you start messing with quartertones or strange things, you shouldn't need to mess with the other values.  this should change your scale you are in. 

changing the base note, c#, i'm not sure about just glancing at it.  and i could be entirely wrong about everything i just said too

^ or if you want re-purpose a button or add a long-press function to 'transpose mode', then you could step up or down at your will, without having to recode the note bit...

i mean - currently the pitches are in D major - like this:  C# D E F# G A B C# D E

i want to move them all down a whole step or up or something...

transpose the thing so i can use it in different keys

maybe change the scale to something more interesting...

What, exactly, do you want to do different than what they already offer? 
I just built myself the stock kit, no mods or anything, but I really like it a lot.  It's a fun little guy.

You can email them, theyve answered tons of questions i had pretty quickly...

i opened up the .pde file to see the code - but i'm unsure how to change the pitches.

i'm not sure if i need to change the frequency numbers or the note array when i look at the code.

probably the integers for the note array?  any heavy coders in the houze?

here's page one of the code:  LINK

I saw something about these a while back... they looked pretty cool, but I think I will stick with my Korg Monotron for now...

Aren't these based off of Arduino? Try looking on arduino.cc, they've got a great community there.

anyone messing around with this thing - it's pretty awesome

just checking to see if anyone has one or if anyone has any custom code that runs on the thing

i searched around and doesn't seem like anyone has posted any alternative code

i want to change the key center of the thing and the layout of the pitches - any help?