Here is a traffic light system based on Arduino that can be used in a 3-way ond 4-way intersections. It has an additional blinking orange led that is used to signal when the pedestrians can cross the ...

This Arduino-based Pomodoro timer project also uses this 25-minute cycle. Once you push the button to start the timer, it will run for 25 minutes, display a count-up timer and a "Study time!" ...