Hi all,
I'm working on an encoder-to-arduino interface. I have arduino Unos, which means that its two interrupt pins are right next to each other. I am using a quadrature encoder with 200 counts per revolution, rotating at around 200 rpm. This is apparently *really* fast for an arduino (40K interrupts per second) especially when also using serial. My arduino tends to crap out (it freezes and serial is not longer sent), and this problem occurs arbitrarily (it may happen in one second of turning it on, it may take a full minute).
I've soldered a decoupling cap. between the two interrupt pins and this *appears* to fix the problem, but I'm not sure if the problem actually got fixed or if I just magically happened to get it to work for a few days and it will fail again. Does it make any sense at all that a capacitor between two digital pins that are beside each other and toggling rapidly would help? Would that setup (without the cap) be a recipe for killing the circuit, or could it be something else?
Mike