millis()
- ArduinoTwo traffic lights at a crossroads Two Arduinos talk over a wire: traffic light A controls the crossroads, B listens and reports when it has stopped, and with millis() both notice a fault.
- ArduinoButtons done right A button with INPUT_PULLUP, counting presses, contact bounce, debouncing with millis() and with the Bounce2 library, and telling a press from a hold
- ArduinoDetecting the ball The Arduino detects the ball: a microswitch on a ramp, a hit timed with micros(), why Bounce2 misses a short hit, a tilt and a Hall sensor with a magnet