stopwatch lcd module in stock

I made a Stopwatch with 2 buttons, I want that a button run the timer and pause if I press it again, and the other to reset the chronometer. I did the stopwach run but i can’t make it pause, rerun and reset, can you help me?

This stopwatch is shock and water resistant and has a large 5/8" high display for good visibility. 1/100 second resolution stopwatch with split time display. Also features an alarm clock with chime, calendar and 12 or 24 hour time modes. The rounded, ergonomic design fits neatly in your hand.

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