In Archimedes' day, close approximations of pi had been known for over 1,000 years. An Egyptian document dated to 1650 B.C., for example, gives a value of 4 (8/9) 2, or 3.1605. Archimedes' value ...

Modern micro-controllers are absolute marvels, but it isn’t too many projects use one and nothing else. For an example of such simplicity, take a look at [oyama]’s Pi Pico MIDI looper.