The kit presented below includes the USB-A to USB-B cable as well as the wiring harnesses for two players.

The wiring harnesses includes grounding and buttons :

• 1 x chain of grounding wire with connectors : 1 pin female header (Black)
• 4 x stick and buttons wires : 4 pins female headers (Blue, Yellow, Red and Brown)

USB Adapter kit

USB Adapter Front

USB Adapter Back

Except for the black grounding, it is up to you to use whatever color suits you.

However pay attention to the kit type because there are 4 :

1. Sticks (Happ) with 4.8mm terminals and buttons (Sanwa) with 2.8mm terminals
2. Sticks (American) with 4.8mm terminals and buttons (American) with 4.8mm terminals
3. Sticks (Sanwa) with 5 pins and buttons (Sanwa) with 2.8mm terminals
4. Sticks (Sanwa) with 5 pins and buttons (American) with 4.8mm terminals

For this specific blog post, we don’t care much as wires will be cut and soldered to the DSUB-15. Still, you might be interested in a specific set if you plan to convert your Neo Geo stick using Sanwa hardware or other. This topic is however outside of our topic.

Note : It’s also possible to actually completely unsolder the headers from the USB adapter board and solder wires directly from PCB to DSUB-15. For this exact reason I’ve purchased both the bare PCB and a kit.

Reminder : The Neo Geo AES stick has 4 micro switches for stick (Up+Down+Left+Right) and 6 buttons (Select+Start+A+B+C+D). We only need 10 wires + 1 ground.

What about polling rate?

This kind of cheap USB adapter (“Zero delay”) usually relies on a 125 Hz polling. This means you can expect a ~8 ms average latency. While this should be just fine for our retro needs, this falls short when compared to 1000 Hz (~1 ms) devices.

If you want 1 ms delays, have a look at the GP2040-CE project which uses a Raspberry Pi Pico and other compatible boards. See https://gp2040-ce.info/

Warning : The Raspberry Pi Pico does not support two players on a single PCB due to the number of required inputs. Add-ons are available but this increase the overall complexity of the project.

A “RP2040 Advanced Breakout PASSTHROUGH” (like the GP2040-CE V5.6E – Fight Board) with wiring harness and USB cable costs around 45€ excluding shipping. Which is a totally different category than our cheap unbranded Chinese board.

If you want a simple single board for 2 players, don’t go anywhere and proceed below.

What are the headers?

The USB adapter board is not built for the Neo Geo AES. As such it comes with pins that you might want to ignore (ie : L1/L2, R1/R2) .

The black headers are 2×20 and could be used with 40 pins ribbon cables. Not all pins are connected.

The outer pins are all ground, inner pins are “active” and used for wiring. I’ve marked with * the ones used by a Neo Geo AES arcade stick.

Here is a break down per player of the black headers:

• GND : Ground, shared with all buttons for both players
• Analog stick
  • AL* : Left
  • AR* : Right
  • AD* : Down
  • AU* : Up
• Buttons
  • Main action buttons
    • A*
    • B*
    • X*
    • Y*
  • Bumpers
    • L1 : Left bumper
    • R1 : Right bumper
  • Triggers
    • L2 : Left trigger
    • R2 : Right trigger
  • Select*
  • Start*
  • L3 : Left stick button
  • ? Not connected
• Special
  • Mode : Switch between D-Pad and helmet
  • Turbo : Turbo mode

The board features two additional white headers:

• 4 pins : USB pins (XH2.54 4p)
  • +5V
  • D-
  • D+
  • GND
• 2 pins : Power from USB (LED lights)
  • GND
  • +5V

For the most adventurous, you will have noticed pads for pogo pins. Those are used to program the microcontroller.

Soldering the DSUB-15

Testing the adapter in Windows