DaemonBite Sega Controller To USB Adapter

Introduction

This is a simple to build adapter for connecting Mega Drive (Genesis), Master System (+ Atari and C= controllers) to USB. It supports 3 and 6-button Mega Drive controllers and 1 and 2-button SMS/Atari/C= controllers.

The input lag for this adapter is minimal. Here is the result from a test with a 1ms polling rate on a MiSTer:

Controller	Samples	Average	Max	Min	Std Dev
Original 3-Button Mega Drive Controller	2342	0.75ms	1.28ms	0.24ms	0.29ms
8bitdo M30 Wireless 2.4G	2348	4.54ms	8.05ms	2.22ms	1.31ms

The Mega Drive gamepad interface is based on this repository : https://github.com/jonthysell/SegaController but almost entirely rewritten and a lot of optimisations have been made.

Parts you need

• Arduino Pro Micro (ATMega32U4)
• Male end of Mega Drive controller extension (or DSUB 9Pin Male connector and some wires)
• SPDT Switch (2.54mm/0.1" pitch)
• Heat shrink tube (Ø ~20mm)
• Micro USB cable

Wiring

How to assemble

(The switch goes to pins GND-GND-2 even if the picture above shows it connected to GND-2-3)

The Switch

When the switch is in the position closer to the USB port of the Arduino Pro Micro, the adapter will be in SMS/Atari mode. When it is in the other position, it will be in Mega Drive/Genesis mode.

License

This project is licensed under the GNU General Public License v3.0.