With the default code you go 1 octave up or down.... nothing in the middle.
A way to do it is to use a variable (similar to the "divider") to change keep the odd samples like read_pt_A = read_pt_A + 1; and the even samples like read_pt_B = read_pt_B + 2;

It may sound a bit confusing.. I am still thinking in a simpler way to so it...

This delay based effect is based in dopler effect. I think the way of gettin 1/2 octave up would be increasing index by 1.5 instead of by 2. As this is not possible, you could have a real index variable, and increment it by 1.5 each iteration, but only use its int part for accesing a position in the buffer. For example, assume that you start at position 1. The next iteration should be at 1+1.5=2.5 for getting a 1/2 octave shift. So you use the position (int)2.5 thats equal 2. The next iteration should be 2.5+1.5=4. Sou you use sample 4. This would make you skip a sample every 3, and get a pitch shift in the middle. This is just an idea, i have not tried this.

Hello,

Does anyone know where I can find the study mentioned? The links are now "FORBIDDEN"

Thanks, Aaron

JR wrote:
" D. Goswami, H. Narula and C. Rogers have the best study about Real-Time DSP Pitch Shifting applicable to Arduino/C programming I have ever read"

You are right, the original document:Is not there anymore.

We have been trying to find the original article and it is nowhere to be found, no PDFs, no google cache, nothing.
The only hope is to try to contact the authors " D. Goswami, H. Narula and C. Rogers" at CNEL University and ask for the pdf.