Looking for guidance in frequency measurement

[turbosupramk3]

Thanks for the datasheet help. How does this look?

Looking for guidance in frequency measurement

The datasheet can help: A 10k inline at the ? will not help. Maybe a 10K from the ? up to 5V per the datasheet would help: [image] I think the INTERNAL_PULLUP resistance is on the order of 20K-50K, so an external pullup of 1-10K might give better frequency response.