I am new to Arduino. I was inspired to dive in by this video and post on the Make Magazine website:
http://blog.makezine.com/archive/2009/08/collins-lab-guitar-pedal-modding-wi.html . Please watch the video. I think it will give a nice background to interpret my questions below.
The sketch can be found here: http://code.google.com/p/makezine/downloads/detail?name=WavePot-090819a.zip&can=2&q= .
I have successfully executed a bunch of the Arduino tutorials, and now I am ready to jump into hacking guitar pedals. I have some questions about the sketch that Colin Cunningham made for the above application.
In reviewing the sketch, it seems like there arrays of hexadecimal values (the so-called "wave tables") that can be sent to the potentiometer in sequence, thus creating a "low frequency oscillator". It seems that on each pass of the loop the next hexadecimal value is arrived at by adding 1 to the value of the index for the array that holds the hexadecimal numbers (in the sketch that incrementing of the index seems to be represented by "i++").
My question is how and when does the index of the array loop back to index 0?
Also, the variable 'rate' is defined as an integer, but it is being assigned hexadecimal values. I am guessing that the Arduino software automatically translates the hexadecimal values into integers. Is that right? (CORRECTION: I was completely off base. It is the variable "resistance" which is a byte that is being assigned hexadecimal numbers.)
I am also wondering what modifications would need to be made to controll multiple digital potentiometers simultaneously (using for example a AD5206 which has 6 digital potentiometers built in).
Any thoughts, help, or direction will be much appreciated.