Dual Atari joystick adapter v2

Features

• Supports two Atari / C64 / Amiga etc. digital joysticks simultaneously
• Full-speed USB with up to 1000 Hz update speed (*)
• Supports paddles on both ports
  
• Supports SMS, Megadrive 3- and 6-button gamepads on both ports
  
• Works in Windows, Linux, Mac (standard HID game controller, no drivers needed)
• Works in all major emulators (VICE, CCS64, WinUEA, Stella to name a few)
  
• Upgradeable FW (Microchip compatible HID bootloader)
• Detects controller type automatically, no need to change firmware
  

Hardware

Layout

• Through-hole version. Easy to build as DIY project. Fits Hammond 1591M enclosure
  
• SMD version with through-hole D-connectors and USB connector. Fits in smaller New Age Enclosures Network Cube enclosure

Eagle 3D rendered through-hole version board
 
And here's the SMD version, also rendered with Eagle 3D.

Finally, here's photo of actual through-hole version board.


And here are schematic and board files available for download:

jakadapter 2.2 through hole Eagle .sch and .brd, Gerber files, PCB order from PCBWay

Firmware

• Support for paddles and Megadrive controllers also on port 2
• Added anti-jitter filtering to paddle readout. Now paddles give very stable but quick readings.
• Reduced Megadrive 6-button controller button polling to 333 Hz as some controllers were giving problems with 1000 Hz. Directional pad and B & C buttons are still polled at 1000 Hz
• Added text 'Stelladaptor' to USB description so that Stella emulator uses paddles correctly
• Megadrive controllers are recognized during USB enumeration (plugging USB cable in). Standard joystick and paddles are automatically recognized without re-plugging USB.
• Support for bootloader
  

How to build it

For a DIY build, it is easier to build the through-hole component version. This chapter describes the steps required to build it. It assumes you have basic electronics tools and know how to use them.

Order the parts

Order the parts which are listed in the BOM. To make it easier, I have gathered a Digikey shared cart and a Mouser shared cart which have all the required components except the PCB.

Order the PCB

You can order a batch of 10 boards for $5 + shipping (approx. $13 total) from PCBWay using this link. If you haven't yet registered to PCBWay, you can register via this link and get some free initial credit (and also earn me some credit as well). Or use the Gerber package and order boards from your favorite manufacturer. Remember that board thickness should be 1.2 mm to fit to enclosure.

Get a PIC programmer

If you don't have a PIC programmer or don't have a place/friend where it could be programmed, the cheapest option is to buy a PICkit2 or PICkit3. Also the cheap Chinese clones e.g. from eBay will usually work.

Solder the components

Assembling the PCB is very straightforward job. Component locations are marked on silkscreen, but you can also use this assembly drawing to find which part goes where. Components IC1, RN1 and RN2 need to be mounted with correct orientation. Pin 1 is marked with a dot or notch, they have to match the assembly drawing. It is advised to mount the d-sub connectors first with screws to the PCB and then solder the pins. You can use 8 mm long M3 screws and M3 nuts. The BOM and shared carts specify #4-40 3/8" imperial screws because those are better available in Digikey and Mouser.

Program the PIC

Download the latest firmware. Information on how to program the PIC, see here.

Cut holes to the enclosure

This is maybe the trickiest part in building the Jakadapter. A proxxon or dremel is handy, but a fretsaw or knife will work too. The PCB will be trapped between the enclosure and its cover. I don't have any drawing or template for this, it is best to cut a little at a time and do frequent trial fittings.

How to use it

There isn't much to instruct here. The Jakadapter will be recognized as two HID compatible game controllers and doesn't require any drivers. You just need to select the Jakadapter from your emulator to be used as controller. You don't need to do any calibration as was required with old analog PC joysticks. It really is plug-and-play.

Testing the operation

To test operation of Jakadapter and also operation of your maybe 30+ years old joystick, you can use the tools provided by operating system.

On modern Windows versions, the joystick calibration application can't be found from the control panel anymore. But it still is there, you can run it by pressing Win+R and type joy.cpl and hit enter. Or on Windows 10 just open the start menu and type joy.cpl. Unfortunately Windows can't read the USB descriptors properly and it will display both ports of Jakadapter with same description. Microsoft hasn't bothered to fix this even though the bug has been there at least from Windows 2000.

On Linux systems you can use e.g. jstest command line tool.

Updating the firmware

The Jakadapter uses a bootloader, so the PIC programmer is not required for updates. You can enter the bootloader mode by keeping joystick 1 fire button pressed down when connecting the USB cable. You can then use the update tools suggested on the my USB HID bootloader page.

Using paddles in VICE

The VICE supports paddle emulation only with mouse. In order to use Paddles in VICE with Jakadapter, I've created a special firmware. In order for it to work, the mouse acceleration needs to be completely switched off. I have detailed the setup procedure in this post on Lemon64 forum.

Other joystick adapters