Want to hook up a Wii Nunchuck to an Arduino but don’t want to cut up the cord on your Nunchuck? Yeah me too. So I made some of these:
It’s a small PCB that adapts the Wii Nunchuck connector to standard 4-pin header. I call it the “wiichuck adapter”. It plugs directly into the Arduino, no wiring necessary. You can get one too for $4.
Available from the following wonderful shops:
– FunGizmos.com. FREE DOMESTIC SHIPPING. International shipping for $1 more.
– Little Bird Electronics (Australia)
– SparkFun. Ships domestic & internationally. Be sure to order header pins too!
– and just about any SparkFun distributor
One of the coolest things about the Wii (to me) is that the expansion port on the bottom of the Wii remote is an I2C serial connection. This means that anything that plugs into that port can work with microcontrollers like the Arduino or Basic Stamp or others. Of the available peripherals, the Wii Nunchuck is one of the best. It contains a 3-axis accelerometer, a 2-axis joystick, and two buttons. Hooking up a Wii Nunchuck to Arduino is easy and I have class notes describing how to do it. But cutting off the connector of the Nunchuck to get at the wires is a little drastic.
This “wiichuck adapter” let’s you play with the Wii Nunchuck and other Wii remote peripherals without needing you to cut cables. Just plug it into the Wii Nunchuck, then into the Arduino, in to Analog In pins 2,3,4,5. Pins 4&5 are the I2C communication pins and Pins 2&3 can act as the power supply for the Nunchuck.
This is what it looks like plugged into the Nunchuck by itself.
Nunchuck and Other I2C Devices (like BlinkM)
You can use other I2C devices at the same time as the Nunchuck. The I2C bus allows for multiple devices. For instance, if you have a BlinkM and also want to use a Nunchuck, no problem. The pinout of the BlinkM and the wiichuck adpater are the same. Just solder a little 4-pin socket header to the top of the wiichuck adapter.
And then you can plug in a BlinkM right on top.
Software
To make it a little easier to play with the Nunchuck, I made a little Nunchuck library for Arduino and demo:
– nunchuck_funcs.h
– WiichuckDemo.ino
(Or better yet, check out the github repository for it all zipped up. Just unzip and open the .ino in Arduino)
It is based off the original research done by Chad Philips of Windmeadow Labs. The library uses the Wiring I2C library called “Wire”. This library is built-in to Arduino, as long as you have the latest Arduino development environment (0010 currently). To see another Arduino sketch using this library, you can check out the BlinkMChuck example that’s part of the BlinkM examples.
The library functions are:
– nunchuck_setpowerpins() — power up a nunchuck plugged directly into an Arduino on analog pins 2,3,4,5.
– nunchuck_init() — init a nunchuck connected to an Arduino
– nunchuck_get_data() — get a data packet from the Nunchuck
Then you can get at the data packet using various helper functions like:
– nunchuck_accelx() — get X-axis acceleration
– nunchuck_zbutton() — get Z-button state
– …and so on, see the header file for a complete list
Nunchuck Information
– Wiimote/Extension Controllers/Nunchuk — info page about the Nunchuck on WiiLi (Linux for Wii) site
– “Wiimote Accessory Bus” — docs about the Nunchuck’s connector.
Getting One / How to Order
Available from the following wonderful shops:
– FunGizmos.com. International shipping for $1 more.
– Tinker.it (UK)
– Little Bird Electronics (Australia)
Update 20 Feb 2008: Over 200 wiichuck adapters sold to more than 50 people in 5 countries. I still have some available if anyone wants one. To those who ordered up to now, you’ll be getting them in the post in a few days.
Update 29 Feb 2008: Over 300 wiichuck adapters sold and I still have many more left. Get yours if you want one. :-) Anyone that’s ordered before today should receive their adapters via first class post soon. I’ll be unable to mail out any orders for the first week of March.
Update 24 Mar 2008: I still have several left. If you’re in AU, you can also get the adapter kit from Little Bird Electronics.
Update 11 Apr 2008: Updated the nunchuck_funcs.h library to easily work with a nunchuck plugged directly into an Arduino by adding a nunchuck_init_with_power() function (see comments below). Also, I still have several adapter kits for sale.
Update 6 May 2008: All Out! But I’ll be doing another board run in a few days and will update here when I have more available.
Update 8 Jun 2008: FunGizmos.com is now carrying Wiichuck adapters! They also have lots of other cool things, like BlinkMs. :-)
Update 7 Jan 2009: Both FunGizmos.com (US) and Tinker.It(UK) carry the Wiichuck adapter.
Update 31 Mar 2009: Fixed small bug that made it not compile under more recent Arduino, and fixed links. Also: if you’re having problems getting this to work, in the Arduino software, go to the “Boards” menu, switch to a different Arduino board type, compile, then switch back to your type. This forces a recompile of the Arduino I2C/TWI library that sometimes doesn’t get compiled correctly.
Update 18 Feb 2010: Updated API description to note that “nunchuck_init_with_power()” was removed in favor of “nunchuck_setpowerpins(); nunchuck_init();”.
Update 6 Dec 2011: Updated to work with Arduino 1.0 (still works with Arudino 0023 too). Changed download links to github repository.
Hi 2RobotGuy,
Yeah it’s possible you blew your Nunchuck. Do you have access to a Wii so you can try it there? I think I’ve hooked up a Nunchuck backwards once with no ill effect, but Nintendo can change the internals of the Nunchuck so it may be yours is slightly different electrically than mine.
Please help,
If you hook-up the Wii nunchuck upside-down in the Adapter, Does it mess up the electronics inside of the NunChuck? Had it working before with the code and Now it seems like it is broken. Any Ideas before I buy another NunChuck?
FunGizmos.com carries the wiichuck adapter and ships to Germany.
Do you ship to Germany, too? Or are there any eagle files?
BigTeddy
Hi Jaap,
I’m also trying to get a wireless Nunchuck working, but haven’t had success. I’m using a Nyko’s Kama Wireless Nunchcuk. What brand are you using? I adapted Michael Dreher’s code, but haven’t had much success. I can’t seem to get the wireless blue receiver light to start flashing (indicating it’s look for the wireless transmitter). Is this supposed to happen after the nunchuck_init routine? The receiver Dongle sends the ACK bit after all the code I send it, but no flashing blue light…Can you clarify when this flashing light is suppsoed to happens in relation to the code?
Also, does anyone have Michael Dreher’s email address?
Thanks,
ILAN
Wiireless Servo
Hello, I wanted to control servo’s with a wireless nunchuck. First I succeded connecting the wireless nunchuck to arduino using the Wiichuck adapter and the wireless nunchuck controller pde from Michael Dreher. However this pde is rather complicated. So I used a spreadsheet to compare the Michal Dreher pde with Tod E. Kurt’s NunchuckServo pde. I reorganised, lined-up and numbered all sub-setup and sub-loop functions. I stripped some #ifdef sub functions from Michael Drehers program that I did not seem to need. Than I added the servo related sub functions from Tod E. Kurt’s NunchuckServo pde and got it all working! See http://spreadsheets.google.com/ccc?key=0AhVc2ar4ldv7dEU0NFFqN1hkblBEQ1ExZjQxWThnOUE&hl=en for this spreadsheet. You can copy the pde from the spreadsheet to pde directly.
Greetings, Jaap
when i try to send or verify it, it says …location…\/WiiChuck_funcs.h:58: error: expected ‘,’ or ‘;’ before ‘{‘ token
what should i do
Hi Jaap,
Yes, the placement of the I2C pins on the Arduino MEGA is different than on a normal Arduino. On the MEGA they are dedicated pins on the other side of the board. (And besides, the new pins on the MEGA means you physically can’t plug the adapter into analog pins 2,3,4,5 like on normal Arduino)
So this means you can’t just plug in the Wiichuck adapter. Instead you’ll need a breadboard and some jumper wires. You would wire it up like below (imagine the BlinkM in the picture is the Wiichuck adapter)
(click for larger version)
Hello again! Writing down your problem sometimes is almost solving them. I started reading about Wire.h and read that the I2C pins are different on the Mega. When connecting to pins 20 and 21 I get the right readings when using the Michael Dreher pde!
However my question remains: What is wrong when I don’t get power on analog pins 2 and 3?
Most important though my Wiireless setup works!
Greetings,
Jaap
Hello, I have the Arduino Mega board and got myselve a wiireless Nunchuck and the adapter from Sparkfun just before reading of the problems to connect it. So far I have no luck connecting the two.
I just discovered that the analog pins 2 and 3 aren’t powered. If I plug the adapter in a breadboard and connect the powerpins to GND and +5V than the receiver leds light up. They don’t when the adapter is plugged directly into pins 2-5.
So I think something is wrong with the libraries. I have tried BlinkMChuck.pde with matching nunchuck_funcs.h. But still no power on pins 2 and 3.
I know for wiireless other code is necessary, but I got the power problem with all pde’s I have tried. And I’thinking if this part of the pde doesn’t work other parts won’t too.
Hi Ilan,
At the time I made the adapter (and I think still), no one quite knew what that pin did, but some assumed it was some sort of device wakeup (“attention”) pin. The Wiimote didn’t seem to use it though.
As for the wireless nunchucks, some people have gotten them working. Check up-thread, but I think the first was this:
http://www.windmeadow.com/node/42#comment-3130
Hi,
I recently got a WiiChuck Adapter and was wondering why the “att” pin (middle pin on bottom row) on the nunchuck is not routed to anything on the adapter..What does this pin do? Is it necessary? I’m specifically trying to use a wireless Nunchuck by Nyko, so I’m wondering if this pin has any relevance on either the wired or wireless nunchuck…
Thanks for your help! -ILAN
First of all thanks a lot for all the information and the code. I have a basic problem with accelerometer.
The x and y axis looks to be independent, somehow y axis and z axis look like they are kind of dependent. The accelerometer (as per many websites) is indeed 3axis accelerometer. There is something I am missing out here.
Thanks in advance for the help.
i think a got a problem at nunchuck_init(). while i run the code below,it only tell me that the WiiChuckpower ready but can’t see the WiiChuckinit ready\n,it hurt me some days ,who can help me.thank you very much.
—————-
Serial.begin(19200);
nunchuck_setpowerpins();
Serial.print(“WiiChuckpower ready\n”);
nunchuck_init(); // send the initilization handshake
Serial.print(“WiiChuckinit ready\n”);
hello… I was wondering if you can help me to figure out the meaning of one of the bus pins in my wireless nunchuck resiver
I have this
vcc
gnd
data
clk
wcs ????????????????? can be wireles control sistem???????? I don`t know
can you help me guys please
because I try to conect the wireless resiver into the arduino and not conect that pin because I don`t know what it is
and maybe that is the reason because do it not work
thanks