Designing a mains frequency monitor

Dan Watson writes:

This is the second in a series of posts about designing a mains frequency monitor using the Microchip PIC 16F1619 microcontroller. In this post we will take a look at the first revision of the board that I designed for the project and some of the features that it adds. Be sure to read Part 1 of the project write-up if you haven’t done so already.

Designing a mains frequency monitor – [Link]