Connecting Comparator to Axon

[airman00]

I've set up a comparator circuit and it's all working, now I want to connect the output of the comparator to an Axon digital input pin. What is the maximum voltage a digital pin can handle?

[Soeren]

Hi,

This is a generic input protection useable for up to more than 30V
.

If your comparator is the kind with an open collector output it's even easier - just connect the pull up between the output and the controllers Vdd (that's what open collector outputs are specifically made for.

[Admin]

What is the maximum voltage a digital pin can handle?

ATmega640 datasheet, silly

Without a protection circuit, it has to be less than the mcu voltage. Otherwise you'd get negative current. Although I'm sure it has some un-spec'd tolerance . . .