Do you have the Mega2560 data sheet in hand? If you connect a 15Mhz signal to an input pin, you are expecting some kind of response every 66 ns. Is that realistic considering that it is almost the period of one processor instruction cycle?
Do you have the Mega2560 data sheet in hand? If you connect a 15Mhz signal to an input pin, you are expecting some kind of response every 66 ns. Is that realistic considering that it is almost the period of one processor instruction cycle?