Long button push

Ignoring, for the moment, concerns about debouncing, you could catch both the press and the release events to determine for how long the button was pressed.

Thank you. Would you please tell me how to catch both events, do you have any coding example?

Have you even tried googling a bit? Just set the edge of your interrupt to catch the press, then, reverse the edge to catch the release. Most of the work will be debouncing the switch.

Google a bit. Read the MSP430 docs for your processor family. Write some code. Debug your code. Then come back if you have trouble. Programming is *not* a spectator sport. You'll learn by doing.

James,

I agree with your suggestions to Su Jin. However, I want to add a note or two.

Most push-bottom switches do bounce. If that happens while your code is changing interrupt edge, you nay not be able to detect the next two edges. You do need either hardware or software debouncing. Using Timer capture pin to detect both edges is easier.

-OCY