Apologies, I used the wrong function.
Instead of "% 64" try "& 63" if you want the value to loop around.
To stop at 0 and 63, try
encoder[i].count = constrain(encoder[i].count + count_ISR[i], 0, 63);
Apologies, I used the wrong function.
Instead of "% 64" try "& 63" if you want the value to loop around.
To stop at 0 and 63, try
encoder[i].count = constrain(encoder[i].count + count_ISR[i], 0, 63);