stopwatch with button
Stopwatch with start/stop button. Starts counting seconds from when the button is pressed until pressed again. The next time you reset the seconds counter and starts again.
Connect the pins of the indicator through resistors 220кОМ with pin 2-8 of the Arduino. Connect button with pin 9 of the Arduino. Connect the other pin of the button and 8 pin indicator pin with GND.
Download the program to Arduino.