“The “4-Stroke Digital Clock” driven by Arduino is a fun emulator of an internal combustion engine in a digital Clock.
Hours and minutes digits represent the pistons moving and with a precise RPM control (100 to 800).
The RPM are shown by two columns in the center of display.
Another interesting visual information is the firing sequence “1-3-4-2” of cylinders.
Spark starts when the piston is at the top of cylinder in the compression cycle.
The code is a good exercise for managing dot matrix pixels and for introducing a simple animation feature.”