I came here looking for exactly this kind of program also with the intention of using it with Rocksmith (however I'll be playing guitar, not bass).
How have you found it?
Can you use a dial to adjust the number of steps the pedal will pitch shift?
Can it pitch up as well as down? (If my guitar is setup for Eb, could I use this code to change to E standard as well as D or C standard as needed?)
Does it only work in full steps? (ie, can you use it to get around retuning for a song that is in A:447 ?)
As I said in my previous post, it is absolutely possible to add more intervals, but a huge "if then" statement is expensive (computationally speaking) and I currently use a cut down version to mitigate the delay.
If you want to add intervals: Variable "POT0" contains the position of the Potmeter if this is "zero" the potmeter is turned all the way left, if it contains the value "4096" it is turned all the way to the right. So in theory you could define 4096 pitchshift intervals. Given the processing delays you would incur that might not be feasible. Also I dont think the program would fit in the Due's memory.
My advice would be to mess around with the code, if you tell windows to "listen to" the Rocksmith cable you should hear the notes you play and this will help you in determining the sample skip intervals you need.
About continuous pitchshifting.
This would require a different method than is used here, and without using a hexaphonic pickup you would be restricted to single note playing.
This method would first have to determine the root-frequency being played.
Then apply some form of frequency modulation to pitchshift it an arbitrary interval.
And finally output it.
This is not trivial (and the reason real Guitar Synthesisers are so bloody expensive ) and would take a smarter person than me to program.
If you have more questions about the code, don't hesitate to ask.
I hit the button to order the shield yesterday. It'll be 2 weeks before it gets to me however - so plenty of time to do some more thinking and devising exactly what I need / want and how to go about it.
Thank you so much.
Finally got my pedalshield all working (100% user error) and just cranked out some C# standard tuned songs on a E-standard guitar.
I had to tune to correct around 20 cents that the pot didn't seem to have the adjustment capacity to tweak - but YES!
Fear Factory on an E-standard guitar........ Love it!
Thanks for writing this code.