Guitar Effects/Filters in real time using low cost DSP?
I'm sure you can implement a simple fuzz or overdrive effect on that board. Apply asymmetrical clipping to you your data, and filter the result with a biquad IIR filter. You'll need a lowpass filter to smooth out some of the nasty high frequencies after clipping (try a cut-off frequency $f_c\in [4..7]$kHz), and you might want a parametric EQ to boost some mid frequencies. You can compute the filter coefficients using the Audio EQ Cookbook. You can probably do much more than that but this should get you started.