Choosing a microcontroller

MegaDrivePlusPlus can run on several microcontrollers, supporting different subsets of functionalities. It can probably be ported to many others with little effort, thanks to the flexibility of the Arduino platform.

If you are not too much into the Arduino world, this variety can be confusing, so here's how to choose the best microcontroller for you:

• First of all, if you have already modded your console with the D4s/Seb mod and the chip is installed in a socket, you are advised to get an ATtiny84: all the wires that are already in place will be fine and you will just need to solder a few more wires to the controller port. If the chip is not installed in a socket, just desolder it but keep the wires, they will all be fine!

• If you have an Atmel AVR microcontroller handy, check out below to see if that particular chip is supported and if the features you are interested in are available on it. If so, use it!

• If you have to buy a new chip from scratch I'd strongly recommend getting an Arduino Nano-compatible board, since:

  • It is cheap (2-3 EUR straight from China).
  • It has plenty of pins, which means it supports all the features.
  • It has an embedded USB port and serial converter, allowing for easy upgrades (and debugging, in case).

• An ATtiny861 is also a good choice, if you prefer sticking to a single chip, as it has plenty of I/O pins and supports all features.

Supported microcontrollers

All diagrams below for ATtiny chips are based on ATTinyCore: https://github.com/SpenceKonde/ATTinyCore. Probably other cores will work as well, but you might have to adjust pin numbers and #defines, so please stick to ATTinyCore..

NOTE: In all diagrams, outer pin number are referred to the physical chips, while inner pin numbers are Arduino pin numbers.

[To Be Continued..]