If they use an Arduino, it should have been an ATtiny. And of course, if an ATtiny was used, there should have simply been a 555 timer. This time, however, [Tim] decided to actually show how this ...

If you’re not familiar with the 555 timer, suffice it to say that this ... the original bipolar formulation as well as lower-power CMOS. While the metal can version is no longer available ...