How is the button press time checked?

Question

Microcontrollers

The essence of the question, when you press the button for 3s, the mode changes in the operation of the MK, so what is the algorithm for checking pressing for 3s?

Answer 1

I would interrupt on such a button, which counted seconds and, when released, checked their number.

Answer 2

Every n milliseconds, the status of the button is polled, as a result, there is an array of states. A button is considered pressed during this time if all counts show that it was pressed. For example so.