Now with:
encoder[i].count = (encoder[i].count + count_ISR[i]) & 63;
works ok. I have 0..63 and 63..0
But this code:
encoder[i].count = constrain(encoder[i].count + count_ISR[i], 0, 63);
I should put this for:
encoder[i].count = (encoder[i].count + count_ISR[i]) & 63;
or add as a new line?