I would like to implement a constant current measure of a dc motor (9V 600mA) using a l298 and the sense pin in the low side of each h-bridge. The problem is the oscillation of tension in shunt, caused by drive PWM. I'm appling a frequency of 62 KHz, the maximum of a Atmega328 and using a RC filter, but the time constat is big. Maybe try a stable dc signal is the wrong way to do it, but i don't know how to do it on another way. I think that maybe it's better to use a interrupt of PWM and in some moment after do the lecture in adc. But I think that this is not the best idea.
Hope that it is clear, my english is not so good.