> It was easy and cheap, before microcontrollers were as friendly to use as they are now.
I got started with AVR microcontrollers with a DIY parallel port ISP adapter: just cut a printer cable in half, solder in 4 resistors and you were good to go :-)
Then spend a ridiculous amount of time re-learning assembly to port the parallel port LED blinking program from DOS to the AVR.
Only needing the few scavenged parts and buying just the MCU was a lot cheaper than buying the "recommended" adapter cable or some eval board, making the whole thing affordable for my 13 year old self.
Things certainly got better. Now it is very possible to get Arduino devboards under $3 from China.
If you must, as it's possible at the same prices to instead get much more powerful microcontrollers with RISC-V or ARM processors, like the ESP32 or STM32 lines.
I got started with AVR microcontrollers with a DIY parallel port ISP adapter: just cut a printer cable in half, solder in 4 resistors and you were good to go :-)
Then spend a ridiculous amount of time re-learning assembly to port the parallel port LED blinking program from DOS to the AVR.
Only needing the few scavenged parts and buying just the MCU was a lot cheaper than buying the "recommended" adapter cable or some eval board, making the whole thing affordable for my 13 year old self.