yes, thank you.
and I already read that and learn to use cmsis dsp.
i am stuck at variable filter because the calculation inside dsp and on the web is differ, although I use the same exact calculation. it is very strange. and obviously using filter with the calculation inside dsp didnt even work. not to mention that the i2s sample is shifted by -8 samples if i set the buffer more than 8....realy, not easy to me for now.
therefore I am trying to port faust because it's make the code less intimidating.
I will probably drop dead if I have to code everything manually ( in which, obviously I have to) with my puny knowledge.