The current wave of lliputing owes a lot to Arduino boards, bacause they have in some way commoditized microelectrobc development. Of course, a lot has changed since Arduino’s first days and a big chunk of Arduino stuff is, today, even too much powerful and too much "cloudy" (i.e. connected to Arduino cloud) to be really interesting from a permacomputing standpoint.

But you can still buy simpler boards – like Arduino Uno, the (more or less) original one - and start interesting projects on them. In the collapse/frugal computing sense, they’re perfectly viable systems. And if you don’t like the Arduino C-like language, there are other ways. Like MicroLisp or MicroPython.