We know that measuring the speed of light with an ... with the setup though: with the Arduino running at 16 MHz, a photon will travel 19 meters in one clock cycle. Even with some very clever ...

The build relies on that old stalwart, the Arduino Uno, to run the show. It’s hooked up to a DS3231 real-time clock module so it can keep accurate time for long periods, as is befitting a clock.