I am using 9 optical encoders and am looking for a solution that avoids having to use several micro-controllers in order to maximize the number of interrupts-pins.
Right now i am working with the Arduino Mega (ATmega1280) and am reading in 3 encoders over the offered 6 interrupt pins. Having 9 encoder means, i would need 18 interrupt pins!
I found some discussions online suggesting using PCINT pin change interrupts on normal I/O pins or using an external port expander, but i am skeptical as it seems to require to do the actual data polling outside of the interrupt method, which could mean loss of data and therefore losing precision of the encoder rotation value (encoder = incremental).
Oh, and i should probably add that all of encoders will be in use at the same time, giving each up to 100-600 pulses per second.
Any hints, tips or experience reports would be highly appreciated!
thanks!
Eva