| Have you ever wondered how many people have | | | | temperature 'IC') has its own unique address. The |
| been interfacing (or connect) the 'Wii Nunchuck' to | | | | 'Nunchuck' slave I2C address is 0x52. This is how the |
| micro controllers? These 'Wii Nunchucks' contain | | | | master identifies the slave. |
| accelerometers, a type of sensor that can produce | | | | All known 'I2C' device addresses are 7-bit or 10-bit. |
| data from motion (tilting, twisting; movements of the | | | | 'Nunchuck' accelerometer values are in 10 bits while |
| hand). | | | | the joystick values, 7 bits. The 7-bit data is |
| 'I2C', known as 'Inter-Integrated Circuit' or 'TWI' | | | | transmitted as 8-bit. First 7 bits define the device |
| (Two Wire Interface) is the method to connect the | | | | address. The 8th bit defines the read write ('R/W') |
| 'Wii Nunchuck' controller to a micro controller circuit | | | | mode. This eighth bit is set to 0 for write and 1 for |
| board. It serves as a communication link between | | | | read operations. |
| 'ICs' ('Intergrated' Circuit). Therefore, 'I2C' can be | | | | The 'I2C' bus comprises 2 bi-directional, active wires; |
| thought as a communication bus. | | | | the 'SCL' or 'SCK' (Serial Clock Line) and 'SDA' (Serial |
| There are two kinds of devices on the 'I2C' bus, | | | | Data Line). In this project, 'SCL' is connected to |
| master and slave. Master is usually set to the micro | | | | analogue pin 4 and 'SDA' to analogue pin 5. +5V |
| controller circuit board while slave is the 'Wii | | | | power and ground on analogue pins of the micro |
| Nunchuck'. Master always controls the clock line and | | | | controller circuit board are used to power the 'Wii |
| data transfer. | | | | Nunchuck'. |
| Every 'I2C' device (e.g. accelerometer, digital | | | | |