The first AVR ATmega microcontroller debuted in 1998 and took the world by storm. In contrast to other embedded 8-bit processors of the era, it required no external components, could run off a wide range of supply voltages, and worked with the GNU C Compiler when others required you to learn assembly or pay for proprietary tools.Since then, ATmega MCUs remained the staple of hobby engineering. In recent years, their market position has been challenged by single-board computers and the wi-fi-capa...