Create a stopwatch with Arduino and LCD display

A stopwatch is a timer device that can be used to measure the amount of time that has elapsed between the start and stop of the timer. Stopwatches can be mechanical, electronic, or software-based.

A simple stopwatch with Arduino can be created by using the millis() function, which returns the number of milliseconds since the Arduino board began running the current sketch. By taking the difference between the start time and the current time, the elapsed time can be calculated and displayed.

The basic steps to build a stopwatch with Arduino are:
1- Declare a global variable to store the start time.
2- In the setup() function, initialize the start time by storing the value of millis().
In the loop() function, calculate the elapsed time by subtracting the start time from the current time (millis()).
3- Display the elapsed time on a display device, such as an LCD 2C 16×2
4- The stopwatch can be controlled by using buttons, so that it can be started, stopped, and reset as per the requirement. The stopwatch can be further enhanced by adding features like lap timing, multiple stopwatch and more.