Grumpy_Mike:
I think you are being way over ambitious for a beginner.
Thanks for the reply. It's the perfect first response. I do tend to aim high and I'm patient enough to enjoy every step of the way.
Grumpy_Mike:
To get something to play backwards you have to load it all into memory and put the samples to a D/A in the reverse order. The arduino has 2K of memory, not enough for a quarter of a second of audio.
So to do this you need a lot of memory. You can't use MP3 because the processor is not fast enough to decode it.
A 180 second audio file at a sample rate of 10KHz will take 3.6 M of memory at two bytes per sample.
This is great. I figured as much but neglected to mention. 180 seconds was just me reaching for best case scenarios but of course I'll be taking baby steps.
I'll crawl actually: how about getting an accelerometer or even a pot to control speed and direction of a timer. Would be nice to peak at code/formulas involved in accomplishing that.
Thanks.