Enter the ExtraCore library for Arduino ... pins your project can control. It may not be the most practical use of two Arduinos, but it’s certainly impressive. You can pick up [Dustin]’s code ...

All of the tools you need to work with the FPGA Arduino — the Vidor ... There is one caveat. The FPGA code has a top-level block with lots of I/O pins defined and the corresponding constraints.

As a microcontroller with a limited number of I/O pins ... with an Arduino that you can't with a Raspberry Pi. Read more: 12 Smart Gadgets You Didn't Know Existed Since Raspberry Pi machines ...