The Nunchuk is the first attachment Nintendo revealed for the Wii Remote. Its appearance when attached resembles the nunchaku, hence the name. It features an analog stick and two trigger buttons. It works in tandem with the main controller in many games. Like the Wii Remote, the Nunchuk also provides a three-axis accelerometer for motion-sensing and tilting. Source: https://en.wikipedia.org/wiki/Wii_Remote#Nunchuk
The Nunchuk (model number RVL-004) is the first attachment Nintendo revealed for the Wii Remote at the 2005 Tokyo Game Show. It connects to the Wii Remote via a cord that is about 3.5 to 4 feet (1 ~ 1.2 m) long. Its appearance when attached resembles the nunchaku, hence the name. It features an analog stick similar to the one found on the GameCube controller and two trigger buttons (a last-minute modification changed the two triggers to one trigger and a "C" button, as described below). It works in tandem with the main controller in many games. Like the Wii Remote, the Nunchuk also provides a three-axis accelerometer for motion-sensing and tilting, but without a speaker, a rumble function, or a pointer function. The Nunchuk's accelerometer is an STMicroelectronics LIS3L02AL.
One Nunchuk comes bundled with the Wii console. Additional Wii Remote units are sold separately without the Nunchuk. The two shoulder buttons, formerly named Z1 and Z2 respectively, had been reshaped and renamed since the Game Developers Conference. The circular top shoulder button, now called C, is much smaller than the lower rectangular shoulder button, now called Z.
The body of the Nunchuk measures 113 mm (4.4 in) long, 38 mm (1.5 in) wide, and 37 mm (1.5 in) thick. The connection port was also larger.
The Nunchuk can be connected to any microcontroller capable of I²C (e.g. Arduino's Atmel AVR), where the accelerometer, joystick and buttons data may be accessed. Todbot has created the Wiichuck, an adapter to facilitate connecting the Nunchuk to an Arduino board.
In 2008, wireless Nunchuks became available from one or more third party providers, eliminating the cord that links the Wii Remote with the Nunchuk.
