Connect Nintendo Gamecube controllers to MSX computers.
The msx-joydolphin v2 is an adapter that allows connecting Nintendo Gamecube controllers to MSX general purpose I/O ports.
The main features of the msx-joydolphin v2 adapter are:
- small footprint
- made of widely available electronic components
- behaves as a cord extension between the MSX computer and the Nintendo Gamecube controller
- uses a female standard DE9 connector on the adapter's MSX joystick side
- uses a Gamecube Controller socket on the adapter's Nintendo Gamecube controller side
- no need for external power supply for wired controllers, the adapter draws current from the MSX port
- low power consumption for wired controllers (<20mA)
- serial debug provides information about the operation of the adapter
- supports WaveBird Wireless Controllers (which draw up to 150mA) when powering the adapter via USB
The msx-joydolphin v2 adapter now follows the behavior of the MSX joystick reference diagram of the MSX Technical Databook, even when pin8 of the MSX general purpose I/O port is HIGH. This makes the adapter now work seamlessly with MSX-HID, which required entering FM Towns compatibility mode in msx-joydolphin v1.
Why msx-joydolphin? The first part of the name is pretty obvious: "msx" as this is an adapter for MSX computers and "joy" as this is a joystick adapter. The "dolphin" part comes from the project codename assigned to the Nintendo Gamecube during its development.
The msx-joydolphin v2 adapter uses an Arduino Nano to convert the Nintendo Gamecube controller signalling to the MSX joystick standard signalling.
A small printed circuit board (PCB) is used to easily bind all components:
- The Arduino Nano is connected using female headers (or soldered directly, when using the proposed the plastic case)
- PH2.0 connectors are used to connect cable extensions
- A 2.54 pitch debug header is added for convenience
- Through-hole components are used on the front side
- Surface mount device (SMD) components are used on the back side
- The SMD components use footprints and sizes (1206) to make hand-soldering easier
Connection to the MSX general purpose I/O port is implemented using a DE9 joystick extension cable with a female DE9 connector on one side and a loose end on the other side. The MSX joystick extension cable loose end is wired according to the following pinout mapping.
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|---|
| MSX joystick connector pinout, from controller plug side |
| MSX side pin | Cable color (may vary) | Signal | Arduino Nano side (port/pin/number) |
|---|---|---|---|
| 5 | Brown | +5v | _/5V/27 |
| 4 | Orange | RIGHT | PB3/D11/14 |
| 3 | Grey | LEFT | PB2/D10/13 |
| 2 | Black | DOWN | PB1/D9/12 |
| 1 | Red | UP | PB0/D8/11 |
| 6 | Green | TRIGA | PB4/D12/15 |
| 7 | White | TRIGB | PB5/D13/16 |
| 8 | Blue | OUT | PD2/D2/5 |
| 9 | Yellow | GND | _/GND/4,29 |
The msx-joydolphin-v2 is fully compatible with MSX joysticks and honors the pin8 (OUT) signal.
The adapter uses open collector outputs (using 74LS03 Quad 2-Input NAND gates with open collector outputs) which makes the adapter safer 1 than the standard MSX joystick schematic depicted in the MSX Technical Data Book, as it avoids a series of undesired conditions that can lead to bus contention/short circuits.
Power is drawn from the +5V signal of the MSX general purpose I/O port, which is capable of delivering up to 50mA 2. The msx-joydolphin v2 draws below 20mA from the port when a wired controller is connected, so it is on the safe side. Anyway, the msx-joydolphin adapter uses a Positive Temperature Coeficient (PTC) resettable fuse of 50mA (F1) to limit current in case something goes wrong.
Also on the power side, a 1N5817 Schottky diode (D1) is used to avoid leaking current from the msx-joydolphin adapter to the MSX in case the USB port of the Arduino Nano is connected to a computer or power supply while the adapter is plugged into an MSX.
Connection to the Nintendo Gamecube controller is done via a Nintendo Gamecube controller extension cable with a controller socket on one side and a loose end on the other side. The Nintendo Gamecube controller extension cable loose end is wired according to the following pinout mapping.
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|---|
| Nintendo Gamecube connector pinout, from Nintendo Gamecube side |
| Gamecube socket pin | Cable color official | Cable color actual (may vary) | Signal | Comment | Arduino Nano side (port/pin/number) |
|---|---|---|---|---|---|
| 1 | Yellow | White | +5v | rumble, not used | N/C |
| 2 | Red | Red | DAT | data line, uses 3v3 logic so it connects via a level shifter to PD7/D7/10 | *( PD7/D7/10 ) |
| 3 | Green | Black | GND | ground | _/GND/4,29 |
| 4 | White | Blue | GND | ground | _/GND/4,29 |
| 5 | N/C | ||||
| 6 | Blue | Green | 3.43v | power line, 3v3 | _/3v3/17 |
| 7 | Black | N/A | GND | ground | N/C |
The Nintendo Gamecube controller uses 3.3V for power and logic, except for the rumble motor which uses 5V.
Power for the Nintendo Gamecube controller is provided by the 3.3V pin of the FT232RL integrated in the Arduino Nano, which is capable of delivering up to 50mA 3, enough to power a wired game controller.
As the Arduino Nano is a 5V logic microcontroller, the msx-joydolphin adapter uses a voltage level shifter based on the BSS138 N-Channel Logic Level Enhancement Mode Field Effect Transistor (Q1) to convert the Nintendo Gamecube controller DAT signal between 3.3V and 5V logic levels.
Warning
Do NOT connect the DAT line of the Nintendo Gamecube controller to the Arduino Nano directly, always use a voltage level shifter. The game controller may get damaged if you connect a 5V signal directly to the 3.3V DAT line.
If a WaveBird Wireless Controller is connected then the msx-joydolphin adapter needs to be powered via the mini USB port of the Arduino Nano, as the power consumption (150mA) is higher than what the MSX joystick port can deliver. Althought it won't work, it is safe to connect a WaveBird Wireless Controller dongle without connecting an external USB power supply thanks to the current limitation of the PTC. Also, connection of an external USB power supply to the Arduino Nano won't back-power the MSX computer thanks to the Schottky diode reverse current protection.
Please, use msx-joydolphin-v2 Build1b for making new boards if you want something field-tested.
The Build1b adapter mimics completely the standard MSX joystick behaviour:
- When pin8 is HIGH, the adapter puts all stick and triggers signals in high impedance mode irrespective of their status (as if stick and triggers were not hold in the standard MSX joystick schematic), which become HIGH on the MSX side via the MSX PSG related circuitry pull-ups (matching the expected behavior)
- When pin8 is LOW
- if a stick direction or trigger is hold, the corresponding signal is pulled down to GND causing it to be LOW (matching the expected behavior)
- if a stick direction or trigger is not hold, the corresponding signal is put in high impedance mode, which becomes HIGH on the MSX side via the MSX PSG related circuitry pull-ups (matching the expected behaviour)
This build uses discrete logic components to honor the pin8 signaling (two 74LS03DR quad 2-input positive-nand gates with open collector outputs) and uses open collector outputs which makes the adapter safer 1 than the standard MSX joystick schematic depicted in the MSX Technical Data Book, as it avoids a series of undesired conditions that can lead to bus contention/short circuits.
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| msx-joydolphin-v2 Build1b first prototype unpopulated |
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|---|---|
| msx-joydolphin-v2 Build1b front populated | msx-joydolphin-v2 Build1b rear populated |
Note
Do NOT populate resistor R3 as it is not needed.
The msx-joydolphin v2 adapter firmware uses NicoHood's Nintendo library to read the Nintendo Gamecube controller status, and it is heavily inspired on Daniel Jose Viana "Danjovic" firmware for a similar adapter for Nintendo 64 joysticks.
The following elements are used as inputs:
- digital pad (D-Pad), as direction arrows
- analog pad, as direction arrows
- A button, as Trigger 1
- B button, as Trigger 2
Those elements' status are processed by the msx-joydolphin firmware and transformed into MSX general purpose I/O port's signals on the fly.
A simple acrylic enclosure design for the project is provided to protect the electronic components and provide strain relief for the extension cords.
The enclosure uses a 3mm acrylic sheet.
The enclosure allows access to the USB port of the Arduino Nano without having to open it.
Note
The height of the acrylic enclosure for msx-joydolphin-v2 has been reduced, so the Arduino Nano must be soldered in the same way as when using the plastic enclosure.
Another enclosure option is using an off-the-shelf plastic case of 60x36x17mm.
When using this option, the Arduino Nano must be soldered directly to the msx-joydolphin v2 board and its pin header legs must be trimmed down in order to fit within the reduced space of the case.
Also, you may need to trim a bit the pcb board corners with a file to slide the board into the case.
You can enlarge the existing hole on one of the case sides to access the mini USB connector, and make a new hole on the very left of the same side for the MSX joystick cable.
This way you can easily power the adapter via USB when you connect a Wavebird wireless controller.
You can use a plastic cover (a HDMI cover in this case) to protect the mini USB hole when not in use, as seen on the pictures.
MSX general purpose I/O port
Gamecube controller pinout
- https://allpinouts.org/pinouts/connectors/videogame/nintendo-gamecube-controller-connector-pinout/
- http://www.int03.co.uk/crema/hardware/gamecube/gc-control.html
Arduino Nano pinout
Nico Hood Nintendo Gamecube Joystick arduino library
Daniel Jose Viana "Danjovic" NSX-64 project
Gamecube controller IDs
- https://www.oshwa.org/open-source-hardware-logo/
- https://consolemods.org/wiki/images/a/a1/GameCube_Controller_Pinout.svg
- https://en.wikipedia.org/wiki/File:Numbered_DE9_Diagram.svg
- https://commons.wikimedia.org/wiki/File:Video_Game_Controller_(56427)_-_The_Noun_Project.svg
- https://logo-timeline.fandom.com/wiki/GameCube?file=Nintendo_Dolphin_1999.svg
_-_The_Noun_Project.svg){kind=link}
