Pitch and Mod wheels - ASM tweaking

[Digispunk]

I managed to get hold of a pitch bend and mod wheel set from Alesis, they are the ones found in the Photon midi keyboard.

i got the housing/mounting frame as well which is going to make it much easier to fit into mu Midibox project.

the thing is - the Mod wheel pot is 10k, and the pitch bend wheel is 5k.

The thing is - they both have limited mechanical rotation due to the design of the housing, but the pots are capable of a full 270 degree turn, like standard pots.

does anyone know if i can use these with the Midibox64 software and get the full range of use  - i.e. Pots with limited mechanical turn producing full 0-127 Midi CC values - or do i have to make some changes to the hardware or software?

cheers

Digispunk

[stryd_one]

Well the MIDIbox can be modified to use these, but with the MB64 app as it is, no they won't work with full range. Can you change out the pots for 10k 90degree throw pots?

Edit: or 270degree throw 30k pots if you can mount them so that only the bottom 1/3 is used

[Digispunk]

Hi Stryd,

do you mean that i can modify the Midibox ASM code to work with the limited range of the pots as they are?

cheers

[Digispunk]

Hi, i posted a question about Pitch and Mod wheels in the parts section, and have been nudged towards the software side in search of solutions -

the problem goes like this -

i have pitch and modwheels mounted in housing that can only turn the pots the usual 90 degrees - but the pots themselves are capable of 270 degree rotation -

the pitch wheel pot is 5k and moves 45 degrees either side of the central axis - which rests at the 180 degree point

the mod wheel pot is 10k and moves 90 degrees from 0-90

i am guessing that the MIDIBox ASM file can be modified to interpret the limited turning range of the pots, and map them onto the full resolution of MIDI paramaters,

has anyone had a similar experience and found a working solution through software? or if its not possible through software how about a hardware solution?

cheers

Digi

[stryd_one]

Yeh it should work, for MIDI at least. You get a 10 bit range for your pot position, which is 0...1023. In theory, you'll get 1/3 of your throw, so that's 341.3`... So you can still scale it without too much lost data. It could be tricky though, as you'll have to calibrate it for it's min/max, as it'll be unknown. Have a look around the forum for TK's scaling algo (scaling is the keyword there), it might be handy here.

That's with the 10K pot. the 5K pot might get a bit warm, I don't know. One way to find out... ;)

I dunno, the short answer is yes, it's totally do-able. I can't guess whether it'll be easy, or difficult :)