Project overview

A few years ago, I completed a similar project that used the Gamecube ports that were at the time built into all Wii consoles. Unfortunately, Nintendo later removed those ports from the Wii (eg: Family edition) and the Wii U also has none.

This new project therefore uses the Wiimote extension like the Classic controller does. And in fact, the microcontroller in this project simply pretends to be one.

Features:

• Play virtual console games with the original controller.
• Works on the new Wii U and Wii consoles with or without gamecube ports.
• Appears to the Wiimote as a Classic controller.
• Supports N64 controllers^[2]
• Supports SNES controllers
• Supports Gamecube controllers (Tested with Nintendo official wired controllers^[1] and the Wavebird)
• Supports NES controllers

^[1]Nintendo DOL-008 controllers: Original gamecube controller, japanese version with extra long cable and Super Smash Bros. edition controllers.
^[2] Reported not to work with the N64 reality quest glove.

Assembled and ready to use versions of this project are available in my online store:

Pictures

Converting a NES controller:

NES and SNES support

Classic controller button	SNES controller	SNES controller in NES mode	SNES controller in analogic mode	NES controller
D-Pad	D-Pad	D-Pad	D-Pad	D-Pad
plus	Start	Start	Start	Start
minus	Select	Select	Select	Select
A	A	B	A	A
B	B	Y	B	B
X	X		X
Y	Y		Y
L	L		L
R	R		R

When an SNES controller is used for SNES titles or when a NES controller is used for a NES title, the mapping is simple. But using an SNES controller for NES games is far from perfect if the A and B buttons are mapped to the classic controller A and B buttons.

Enabling NES mode:
Press START+SELECT+L+R+DOWN simultaneously. In this mode, the SNES button placement will be much more adapted to virtual console NES titles.

Enabling analogic mode::
Press START+SELECT+L+R+LEFT simultaneously. In this mode, the SNES D-Pad controls the classic controller left stick. This mode might not be very useful, but beating a friend with such a setup is quite funny.

Restoring standard mode:
Press START+SELECT+L+R+UP simultaneously.

Home button:
Triple-clicking the start button will trigger the home button. (Version 1.9.5 and up)

N64 support

N64	Mode 0	Mode 1	Mode 2	Mode 3	Mode 4	Mode 5	Mode 6	Mode 7	Mode 8
A	A	A	A	A	A	A	A	A	B
B	B	B	B	B	B	B	B	B	Y
Start	plus	plus	plus	plus	plus	plus	plus	plus	plus
L	L	ZR	D-Down	D-Down	ZR	L	D-right	ZR	L
R	R	R	R	ZR	R	R	R	R	R
Z	ZR	L	L	L & R	L	L	L	X & Y	ZR
D-up	D-up	D-up	D-up	D-up	D-up	D-up	D-up	D-up	D-up
D-down	D-down	D-down	D-down	D-down	D-down	D-down	D-down	D-down	D-down
D-left	D-left	D-left	D-left	D-left	D-left	D-left	D-left	D-left	D-left
D-right	D-right	D-right	D-right	D-right	D-right	D-right	D-right	D-right	D-right
C-Up	C-Up	C-Up	C-Up	C-Up	N/A	C-Up	N/A	C-up	C-Up
C-down	C-down	C-down	C-down	C-down+X	N/A	C-down	X	C-down	A
C-left	C-left	C-left	C-left	C-left+Y	Y	C-left	Y	C-left	X
C-right	C-right	C-right	C-right	C-right	X	C-right	ZR	C-right	C-right

Mapping	Activation	Recommended games	Introduced
Mapping 0	L+R+Z+D-up	Mario 64, Kirby 64, Mario Tennis 64, Wii64*, Bomberman hero, Mario Golf, Pokemon Puzzle League	v1.0
Mapping 1	L+R+Z+D-down	Mario Kart 64, Mario Kart Wii, Mario Party 2, Cruisn' USA, Wave race 64, Custom robo v2	v1.0
Mapping 2	L+R+Z+D-left	Zelda Ocarina of time, Paper Mario	v1.0
Mapping 3	L+R+Z+D-right	Super Smash Bros	v1.0
Mapping 4	L+R+Z+C-up	Sin and punishment	v1.0
Mapping 5	L+R+Z+C-down	Ogre Battle 64, 1080° Snowboarding, Pokemon Snap, Starfox 64	v1.0
Mapping 6	L+R+Z+C-left	F-Zero X	v1.6
Mapping 7	L+R+Z+C-right	Yoshi's Story	v1.6
Mapping 8	L+R+Z+(Joystick-down)	Mario Odyssey	v2.1.1

Please help me implement mappings that might be required for other games by sending me user manual pictures.

Special combos:
* When mapping 0 is active, pressing the four C buttons + Dpad left + Z simultaneously sends X+Y pressed status to the console. This opens the wii64 menu.

ZL + ZR:
Before firmware version 2.1.1, ZL and ZR were tied together. Now only Zr is used. For instance, if using mapping 0, the N64 Z button only controls Zr. The old behavior of tying Zl and Zr together can be toggled with: L+R+Z+Joystick_down. (In other words, press and hold Z, L and R, then point the N64 joystick away from you)

Home button:
Triple-clicking the start button will trigger the home button. (Version 1.9.5 and up)

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Joystick values conversion:
The classic controller reports the left stick using 6 bits and the N64 controller reports the stick position using 8 bits. When a simple linear conversion is used, the games feel very wrong. A long succession of tests yielded the following transfer curves which restores the feeling to something much closer to the originals.

It should be noted that values ranging from -32 to +31 can be reported using 6 bits but that in practice the wii classic controller reports values between -24 and 24.


Note: The curve is symmetrically applied to center-to-side stick movements. The output range of value is therefore 0 to 31. Also note that the N64 controllers manufactured by Nintendo never reach the maximum value of 127.

Selecting a curve with firmware v1.5:
In version 1.5, two curves of different sensitivity are offered and configurable using the button combinations below. The adapter stores the setting in non volatile memory so you don't have to reconfigure every time you connect the adapter.

press L+R+Z+A: Default curve (v1.5).
press L+R+Z+B: Alternate curve (v1.4)

Curve selection in previous versions:
Version 1.4.1: Default curve is v1.4, alternate curve v1.1.
Version 1.4 and 1.3: No curve selection possible.

N64 controllers range of values:
The original v1.1 curve did not work well with all controllers. Failure to reach the full game effect (eg: running, performing a tight turn) was the observed symptom. Given the expected range of -24 to +24 on the wiimote side and the actual measured range of values sent by N64 controllers (see below), it makes perfect sense. This was fixed in v1.4.1 and v1.5 and is no longer a problem.

Here is a table exposing the values returned by different controllers:

Controller	X axis	Y axis	Stick condition
Standard N64 red	-82 to 79	-85 to 83	As new
Standard N64 aqua	-80 to 80	-80 to 85	As new
Standard N64 gray	-75 to 75	-80 to 77	Worn
Standard N64 transparent purple	-72 to 80	-80 to 80	Described as "Some wear" on eBay. Quite worn actually..
Standard N64 yellow	-68 to 64	-69 to 80	Extremely worn
Hori pad mini	-100 to 100	-100 to 100	As new
Unknown brand	-88 to 87	-90 to 85	As new
Unknown brand	-128 à 127	-128 à 127	New

Gamecube support

Gamecube	Mode 0	Mode 1	Mode 2	Mode 3	Mode 4	Mode 5
Start	plus	plus	plus	plus	plus	plus
A	A	B	A	ZR	B	A
B	B	Y	B	A	Y	X
X	X	A	X	B	A	R
Y	Y	X	Y	X	X	B
L	L	L	ZL	ZL	L	ZL
R	R	R	ZR	Y	R	ZR
Z	ZL & ZR	minus	R	B	Zr	minus
D-up	D-up	D-up	D-up	D-up	D-up	D-up
D-down	D-down	D-down	D-down	D-down	D-down	D-down
D-left	D-left	D-left	D-left	D-left	D-left	D-left
D-right	D-right	D-right	D-right	D-right	D-right	D-right
Main stick	Left stick	Left stick	Left stick	Left stick	Left stick	Left stick
C stick	Right stick	Right stick	Right stick	Right stick	Right stick	Right stick
L analog
R analog

Home button:
Triple-clicking the start button will trigger the home button. (Version 1.9.5 and up)
Press the following keys simultaneously to trigger the home button: A+B+Y+X+Z+C-Down. (Version 1.7, 1.8 and 1.9 only)

Analog L/R sliders:
The analog sliders are implemented only since version 1.7. In earlier versions, only the digital L/R buttons were functional.

Mapping	Firmware	Activation	Recommended games
Mapping 0	Since 1.3	A+B+X+Y+Dpad-Up	Mario Kart Wii
Mapping 1	Since 1.3	A+B+X+Y+Dpad-Down	SNES virtual console games
Mapping 2	Since 1.4	A+B+X+Y+Dpad-Left	Sonic & All-Stars transformed for the Wii U and others.
Mapping 3	Since 1.4	A+B+X+Y+Dpad-Right	Sonic & All-Stars transformed for the Wii U and others.
Mapping 4	Since 1.7	A+B+X+Y+Z+C-left	For Devolution.
Mapping 5	Depuis 1.9.5	A+B+X+Y+Z+C-right	Super Mario 3D World.

Help me to do better by letting me know the mappings you need.

Special combos:

• A+B+X+Y+L: Toggles an option where pressing the L/R triggers just a little triggers the L/R buttons (early/easy trigger) - Since version 2.2.1

Schematics

Here are two schematics, one for the DIP (through hole) version of the MCU, one for the TQFP (smaller, surface mount) version.

Power supply:
The project uses the 3.3v supply coming from the Wiimote. Standard NES and SNES controllers, even though they were meant to be used at 5 volt seem to work fine. Some controllers built by third parties or otherwise special controllers might not work properly (eg: NES Advantage). N64 controllers are meant to be run at 3.3v so no problem here. Gamecube controllers are normally supplied with 5 volt and 3.3 volt, but on Nintendo hardware at least, it seems the 5 volt supply is only used for the vibration function. Leaving the 5 volt input unconnected seems to work fine.

Battery life:
According to the data exposed in the next section, using an SNES controller, battery life is similar to the classic controller. Battery life however is much shorter if using a N64 controller, but still better than what a wii motion plus gives you.

Here are suggested components for building the DIP version.

Ref.	Description	Suggestions
R1	1.5K resistor	Digikey S1.5KQCT-ND or equivalent.
C1,C2	18pf ceramic capacitors	Digikey BC1004CT-ND
C3,C4	.1uF ceramic capacitors	Digikey BC2665CT-ND
P1	2x3 .100" pitch standard header	Digikey 609-3218-ND
Y1	Crystal 12 Mhz	Digikey CTX904-ND
U1	Atmega168a (ou Atmega168)	Digikey ATMEGA168A-PU-ND

Here is an example built using the above suggested components:

Power consumption

Battery life is inversely proportional to the adapter's power consumption. As shown in the table below, while the adapter uses only 1.6mA, but the current drawn by the connected controller also has to be taken into account. I have included measurements of different Wiimote accessories as a comparison basis.

Note: All measurements were taken at 3.3v between the wiimote and the accessory under test using a modified wiimote extension cable and a multimeter.

Accessory	Consumption
Extenmote v1.1, Atmega168, sans manette	1.6mA
Classic controller RVL-005	1.7mA typical, approx. 3mA all buttons down
Classic controller RVL-005(-02)	1.36mA typical, approx. 3mA all buttons down
Extenmote v1.1, Atmega168, with standard US SNES controller (SNS-005)	2mA
Nunchuk RVL-004	2.3mA typical
Extenmote v1.1, Atmega168, with white Gamecube DOL-003 controller (Japanese)	4.4mA
Classic controller clone	5.5mA typical
Extenmote v1.1, Atmega168, with N64 Horipad mini controller	5.6mA
Wireless Nunchuk receiver (unknown brand)	11.9mA typical
Extenmote v1.1, Atmega168, with N64 standard controller NUS-005	15.4mA
Wii motion plus	22.5mA (Drops to approx. 1.5mA when another accessory is connected)

Conclusions:

• Extenmote with a N64 controller draws less current than the wii motion plus. Battery life should be shorter than with the classic controller but still better than with the wii motion plus.
• Nintendo did a pretty good of keeping the classic controller and nunchuk power low.
• The wii motion plus uses as much as 22.5mA, but the current appears to drop to approx. 1.5mA as soon as an accessory (classic controller, nunchuk or extenmote) gets connected. The impact on battery life the wii motion plus presence has is therefore limited, but it would still be recommended to remove the wii motion plus when it is not required.
• Interesting fact: The N64 Horipad mini controller draws less power than the N64 standard controller.
• The adapter uses the AVR MCU 'Extended Standby' sleep mode. This lowers the adapter power consumption from 4mA to 1.6mA.

Latency

Using an adapter like this one inevitably increases delays (lag) but the good news is that it is quite short (less than 3ms).

Symbol	Parameter	Value	Units	Comments
A	N64/GC poll time	0.4	ms
B	Adapter added latency	2.84	ms	Worst observed case.
C	Wiimote poll to N64/GC poll	2.35	ms	Variable starting point.
D	Wiimote communication time	1.5	ms
E	Wiimote poll interval	5	ms

Note: I define the latency increase caused by the adapter as being the interval between the moment fresh controller data has been completely received and the moment said data has been completely transmitted to the wiimote.

Note 2: Many other elements of the complete system (controller>adapter>wiimote>bluetooth>wii>game>TV) are likely contributors to the total latency. This adapter can only minimise its own contribution to the total latency.

Compatibility

From the console point of view, the adapter acts like (and therefore is) a classic controller. So it should just work with any game supporting the classic controller. To this day, I know of no incompatible games.

But I'm regardless receiving a lot of questions like: "Can I use this adapter with game X?". Well here's a list of known working game software:

• Wii and Wii U system menus
• Mario Kart 8 (Wii U)
• Super Smash Bros Brawl (Wii)
• Sonic & All Stars Racing transformed (Wii U)
• Super Mario 3D World
• Virtual Console SNES and NES games
• Virtual Console N64 games: Mario 64, Kirby 64, Mario Tennis 64, Wii64, Bomberman hero, Mario Golf, Pokemon Puzzle League, Mario Kart 64, Mario Party 2, Cruisn' USA, Wave race 64, Custom robo v2, Zelda Ocarina of time, Paper Mario, Super Smash Bros, Sin and punishment, Ogre Battle 64, 1080° Snowboarding, Pokemon Snap, Starfox 64, F-Zero X, Yoshi's Story

This list is absolutely incomplete. If a game is not listed, it still probably works very well. If you do test an unlisted game, let me know and I will be happy to add it to the list.

PCB

This project does not have a specific PCB because it was not necessary. I am simply using my Multiuse PCB2 again, which is perfect for this project.



Circuit available in the online shop:

Software

Version 2.2.1 July 14, 2022 (Thursday)
Add an option for Gamecube controllers where the L/R buttons are triggered early using the analog reading from the L/R sliders. This option is toggled with A+B+X+Y+L and is remembered between power cycles.
File(s): extenmote-2.2.1.tar.gz (92.1 KB) extenmote-2.2.1.hex (38.5 KB)

Using the .hex files
The Atmega168a has to be programmed using the .hex file. The "fuse bytes" for this project are extended_byte=0x01, high_byte=0xdf, low_byte=0xdf.

For more information about the tools required to program an AVR microcontroller, please visit my AVR programming page.

Source Code (.tar.gz files):
Unless indicated otherwise, the source code is published under the GPL license version 3. Please consult the included gpl.txt file for more information. The project compiles using the included makefiles using avr-gcc under Linux.

Raw values

For compatiblity, my extenmote adapters must convert the joystick values to match those of a classic controller. Unfortunately, resolution is lost in the process meaning that the controllers are not working at their full potential.

Starting with version 1.8, the adapter appends raw values to the standard classic controller. Software unaware of this feature will continue working normally, but the data will be available and usable by applications were it is useful.

This feature is documented in details on its own page. An example using a modified libOGC is also available.

User pictures

Seeing how others build my projects is always a pleasure. Send me your pictures and I'll add them here. Also let me know if you have a name/alias and country I can mention. By default, I will use your first name.

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I received the following pictures on January 12, 2013. This user built everything right into his N64 controller. Note the skillful soldering of the surface mount MCU:

2013-02: Alexandre installed the circuit inside a N64 controller:


2013-02-13: Samuel sent me the following pictures of the circuit installed inside a NES controller:


2013-08-12: Santiago built his adapter by modifying a Gameboy. Game controllers are connected using a selection of modified game cartridges!


2015-05-04: Jonathan from Canada built a pair of SNES/Gamecube to Wiimote adapters:

March 2016: Jonathan added two more adapters to his collection: N64/Gamecube to Wiimote:

References

The folling pages and documents helped make this project possible.

Communication with the Wiimote uses code from the following projet:
DIY Drum Set Controller for the Wii made with AVR

The following were also very useful:
Nintendo Gamecube Controller Protocol
Yet Another Gamecube Documentation
Sci.Electronics FAQ: Super Nintendo Entertainment System: pinouts & protocol
http://www.hardwarebook.info/Wiimote_Expansion_Port
http://wiibrew.org/wiki/Wiimote/Extension_Controllers
http://wiibrew.org/wiki/Wiimote/Extension_Controllers/Classic_Controller

Disclaimer

I cannot be held responsible for any damages that could occur to you or your equipment while following the procedures present on this page. Also, I GIVE ABSOLUTELY NO WARRANTY on the correctness and usability of the informations on this page. Please note, however, that the procedures above have worked in my case without any damages or problems.

Now you cannot say that I did not warn you :)