> Thanks, we got to the point that averaging is enough on IRC tonight
> too... but we had no way to calculate how many samples to average...

I suggest using an IIR filter instead of FIR. You need way less past samples
for each step. The most simple IIR filter is like a charge/discharge (first
order lowpass): e.g. take 90% of your "charge", 10% of the new value, to get
the new charge. Play with the parameters, generalized it's n and (1-n). If
you use less of the current, the thing becomes slower, lower corner
frequency.
Power of two gives the benefit of using shift instead of multiply. Use >16
bit for the charge.

Jörg

-- 
GMX DSL = Maximale Leistung zum minimalen Preis!
2000 MB nur 2,99, Flatrate ab 4,99 Euro/Monat: http://www.gmx.net/de/go/dsl
_______________________________________________
http://cool.haxx.se/mailman/listinfo/rockbox