In this folder you can find a software for an adapter that allows to connect SNES compatible controller to Atari 2600.
It is an Arduino project, but it is written for a plain Atmega8/Atmega48/Atmega88 microprocessor, not for any Arduino board.
To compile it, you need to open the sources in Arduino IDE. You'll also need to install MiniCore from MCUdude. Then you'll be able to select Atmega as a target processor:
Precompiled binaries are available here: releases.
I designed this adapter primarily for my game - Berta and Butterflies. I wanted to make controlling experience more similiar to the "Game & Watch" consoles and be able to move the character to any corner using only one button:
However, the adapter has also a different mode. You can switch the mode by pressing Start+Select at the same time. In this mode it will work as a normal adapter. It means that the arrow keys will work as joystick directions and "Y" button as fire.