Hi, I'm working with a Mega 2650. I'm trying to use the external interrupts on pins 20 and 21 (SDA and SCL), and I'm noticing that there's some unpredictable behavior that doesn't seem to be officially documented anywhere. Specifically, I can't seem to configure those pins to input LOW. I do a dig…

Arduino Mega, SDA/SCL pins, and interrupts

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