Currently Being ModeratedApr 29, 2009 7:13 PM (in response to PsiKTrOn)Re: The RollerShifter - A guitar arpegiator
Nice Job!! Very cool effect!!
If you don't mind my asking, about how many hours work does this represent? How was the learning curve and do you have a programming/DSP background?
Thanks for sharing the video & good luck.
Currently Being ModeratedApr 30, 2009 3:12 AM (in response to richfiddler11)Re: The RollerShifter - A guitar arpegiator
Thank you very much for your feedback.
I programmed the DSP in assembly language.
But, first, I wrote it with a high level simulation environments. I used Matlab.
Matlab is very adapted for the development part.
Then I translated the code into assembly.
This way of developing take more times but split the problems. In the Matlab part I tuned the DSP code to obtain the right sound.
And in the assembly part, I only had to solve assembly problems like writting in the external memory,...
I cannot evaluate clearly the development time. I received my kit for Christmas. But I only spent a few hours by weeks on it.
I'm a phd student in electronic. This background helps me for the development of the effect.
Have a nice day.
Currently Being ModeratedMay 4, 2009 1:18 PM (in response to PsiKTrOn)Re: The RollerShifter - A guitar arpegiator
I love it. -especially the disjointed sounds as well as the octave shifts that you are getting. That is pretty advanced.
How did you use Matlab to help program the pedal? Did you also use Simulink?
What is your goal with this? Do you want to sell the code or modules?, work for Line6?, or share some of your secrets so we can learn from your creativity?
either way, great job!
Currently Being ModeratedMay 12, 2009 8:21 AM (in response to jonsonnenberg)Re: The RollerShifter - A guitar arpegiator
I didn't use Simulink because it's too different from the final code.
I develloped a code that works like the DSP. The advantage is that you can use all the features of Matlab (loading and writing wav file,...) to tune exactly the sound I wanted.
Then, I just converted all the code into assembly.
The most representative example is that i had to calculate the frequency of each note. In matlab, this take one line. In assembly i head to implement a look-up table which reprensents an important task.
I already shared things, I posted on the old forum how i use the external memory. And how i convert easily my code into a step by step debug code.
I think that the full code is hard to understand because due to storage capacity of the program memory, I had to optimize it a lot.
I hope this will help you.
Currently Being ModeratedAug 19, 2009 6:33 AM (in response to PsiKTrOn)Re: The RollerShifter - A guitar arpegiator
Wow! Fantastic job. What's really impressive is the amount of function you programmed. Certainly no one trick pony!
Now, Line 6 just has to put that in my XTL and I'll be very happy....
Hey, Line 6-make a model pack of stuff like this!