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Nintendo Wii Nunchuk controller
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This is a collection of example captures of I2C traffic from/to a Nintendo
Wii Nunchuk game controller.

A Dangerous Prototypes Buspirate (v4) was used as I2C master to talk to the
Nunchuk controller.

Details:
https://en.wikipedia.org/wiki/Wiimote#Nunchuk
http://wiibrew.org/wiki/Wiimote/Extension_Controllers/Nunchuck
http://dangerousprototypes.com/docs/Bus_Pirate
http://dangerousprototypes.com/2009/08/19/bus-pirate-wii-nunchuck-quick-guide/

## Logic analyzer setup

The logic analyzer used was a Saleae Logic (at 1MHz):

Probe I2C pin

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3 (red) SCL
7 (blue) SDA

## Buspirate setup

Connections:

Buspirate Nunchuk I2C breakout adapter

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GND - (GND)
+3.3 + (VCC)
MOSI d (SDA)
CLK c (SCL)

The basic setup after connecting to the Buspirate on /dev/ttyACM0
(115200, 8n1) via minicom was:

HiZ>m (mode)
(1)>4 (I2C)
(1)>2 (I2C mode: hardware)
(1)>1 (speed: 100kHz)
I2C>W (enable Buspirate power supplies)

See below for further per-file I2C commands used.

## sigrok

The sigrok command line used was:

sigrok-cli -d fx2lafw:samplerate=1mhz --time <ms> \
 -p '3=SCL,7=SDA' -o <filename>

The <ms> and <filename> parameters vary depending on the file.

## wii_nunchuk_init.sr

I2C>[0xa4 0x40 0x00]
I2C START BIT
WRITE: 0xA4 ACK
WRITE: 0x40 ACK
WRITE: 0x00 ACK
I2C STOP BIT

## wii_nunchuk_set_reg.sr

I2C>[0xa4 0x00]
I2C START BIT
WRITE: 0xA4 ACK
WRITE: 0x00 ACK
I2C STOP BIT

## wii_nunchuk_data_idle.sr

No buttons were pressed, the analog stick was not moved.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x74 ACK 0x7F ACK 0x7B ACK 0x20 ACK 0x7D ACK 0xC7
NACK

## wii_nunchuk_data_left.sr

No buttons were pressed, the analog stick was moved to the left.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x12 ACK 0x7C ACK 0x48 ACK 0x2C ACK 0x97 ACK 0x2F
NACK
I2C STOP BIT

## wii_nunchuk_data_right.sr

No buttons were pressed, the analog stick was moved to the right.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0xD6 ACK 0x61 ACK 0x4E ACK 0x28 ACK 0x93 ACK 0x2B
NACK
I2C STOP BIT

## wii_nunchuk_data_top.sr

No buttons were pressed, the analog stick was moved to the top.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x74 ACK 0x7E ACK 0x8E ACK 0x70 ACK 0x48 ACK 0x97
NACK
I2C STOP BIT

## wii_nunchuk_data_bottom.sr

No buttons were pressed, the analog stick was moved to the bottom.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x19 ACK 0x43 ACK 0x2F ACK 0x65 ACK 0xA3
NACK
I2C STOP BIT

## wii_nunchuk_button_c.sr

The C button was pressed.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x70 ACK 0x56 ACK 0x9F ACK 0xED
NACK
I2C STOP BIT

## wii_nunchuk_button_z.sr

The Z button was pressed.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x80 ACK 0x78 ACK 0x64 ACK 0x6C
NACK
I2C STOP BIT

## wii_nunchuk_orientation_vertical_top.sr

The Nunchuk was in vertical ("normal") position.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x81 ACK 0x78 ACK 0x63 ACK 0x5F
NACK
I2C STOP BIT

## wii_nunchuk_orientation_vertical_bottom.sr

The Nunchuk was in vertical position, help upside-down.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x71 ACK 0x83 ACK 0x5D ACK 0xD3
NACK
I2C STOP BIT

## wii_nunchuk_orientation_horizontal_left.sr

The Nunchuk was in horizontal position, pointing to the left.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x25 ACK 0x7E ACK 0x7B ACK 0xEB
NACK
I2C STOP BIT

## wii_nunchuk_orientation_horizontal_right.sr

The Nunchuk was in horizontal position, pointing to the right.

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x8F ACK 0x7E ACK 0x75 ACK 0x4B
NACK
I2C STOP BIT

## wii_nunchuk_init_reg_3xdata.sr

I2C>[0xa4 0x40 0x00]
I2C START BIT
WRITE: 0xA4 ACK
WRITE: 0x40 ACK
WRITE: 0x00 ACK
I2C STOP BIT

I2C>[0xa4 0x00]
I2C START BIT
WRITE: 0xA4 ACK
WRITE: 0x00 ACK
I2C STOP BIT

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x77 ACK 0x4F ACK 0x82 ACK 0x3B
NACK
I2C STOP BIT

(for the above values, no button was pressed)

I2C>[0xa4 0x00]
I2C START BIT
WRITE: 0xA4 ACK
WRITE: 0x00 ACK
I2C STOP BIT

I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x75 ACK 0x44 ACK 0x82 ACK 0x34
NACK
I2C STOP BIT

(for the above values, the Z button was pressed)

I2C>[0xa4 0x00]
I2C START BIT
WRITE: 0xA4 ACK
WRITE: 0x00 ACK
I2C STOP BIT
I2C>[0xa5 r:6]
I2C START BIT
WRITE: 0xA5 ACK
READ: 0x75 ACK 0x7F ACK 0x77 ACK 0x43 ACK 0x83 ACK 0x5D
NACK
I2C STOP BIT

(for the above values, the C button was pressed)
