Chuck Todd has built a Arduino compatible Mega2560 ... wait states needed. But since ATMega2560 multiplexes both Data0..7 and Address0..7 on the same 8 pins, there is a performance penalty ...

(The Raspberry Pi does have one pin capable of outputting a PWM ... and [is a] much smaller package," Moir said. The Arduino Mega and its ATmega2560 chip used in the project have "up to 54 ...

Wyatt]’s CPUVolt library provides a fast way to measure voltage using no external components, and no I/O pin. It only applies to certain microcontrollers, but he provides example Arduino code ...