The Retro Adapter connects various controllers to USB. It will support Atari/Commodore (2600/C64/Amiga etc) style joysticks, Sega Master System and MegaDrive (Genesis) pads, Sega Saturn pads and Nintendo NES/Famicom/SNES pads.
I want to add more controllers so the design is going to be modular. Of particular interest are Neo Geo pads, Virtual Boy controllers, X68000 pads, N64 controllers, Playstation/PS2 pads/dance mats/steering wheels and PC gameport joysticks (maybe with Logitech ADI support).
I want to offer kits as well as finished units, (which I will make myself) so the design has to be easy to assemble and cheap. Everything will be open source and sold at cost.
An old Amiga joystick adapter gave me an idea:
A DB25 with some pins removed can accept two DB9 plugs (Atari/Commodore/Sega style connectors). A DB25 shell makes a cheap and easily obtainable case. On the other end will be a USB mini socket and probably a power LED. The board will be held in place with hot melt glue. The case is large enough for all components to be standard through hole types (not surface mount SMT) and thus easy to solder.
Adapters for other controllers would just be a DB25 plug on a PCB, with suitable connectors for Nintendo, Sega Saturn or whatever. Since it's hard to get connectors for some controllers (Sega Saturn, Playstaion and Nintendo in particular) another option is to cut the cable on the controller and wire it in to a DB25 shell, with the original connector out the back like this:
Alternatively an extension cable could be cut in half and used to much the same effect.
(the images above not my adapter, btw
they just illustrate the concept)The only problem with this design is that you can only plug two moulded DB9s in to it - the larger DB9s with screw on connectors only fit one at a time. That could potentially be an issue when connecting, say, two NES/SNES controllers if you want to use the above method. I suppose you could make a DB25 -> 2xDB9 adapter as well
Since this will be a dual controller adapter (two players), it would appear to the computer as two separate joysticks. It's possible that with some controllers (e.g. Playstation) it might only support one at a time, in which case the second joystick would do nothing. Alternatively, it could use show up as one joystick and have the second controller mapped as fire buttons (e.g. up = button 10, down = button 11, left = button 12 etc)
As for the USB port, I'll try and add holes to the PCB so a choice of mini USB connector or captured USB cable is available.
I can think of a few other options:
1. Simple PCB only, user can make their own case. I could do a single player version too.
2. Single player version using SMT components. The case could be smaller, maybe even a DB9 shell, but not easy to solder.
3. Do lots of separate PCBs, one for each set of connectors. Each PCB might be a little bit cheaper (not much) but there would be no expansion options.
Any comments on this would be appreciated.