Interfacing to Wii Nunchuck

[Kamikaze47]

I'm trying to interface a Wii Nunchuck to a PIC using PBP.

From the info on this page (http://wiibrew.org/wiki/Wiimote/Exte...ollers#Nunchuk), I have written what I think should work, but not having much joy.

'init nunchuck: write $55 to $A400F0 and $00 to $A400FB

I2CWRITE i2c_clock_pin,i2c_data_pin,$A4,$00F0,[$55],fail
pause 10
i2CWRITE i2c_clock_pin,i2c_data_pin,$A4,$00FB,[$00],fail
pause 10


'read 6 bytes from $A40008

I2CREAD i2c_clock_pin,i2c_data_pin,$A4,$0008,[STR datain/6]

However each time I read the 6 bytes i get one of three sets of bytes back (each time I read I get the next set, and then it loops back to the 1st set).

80,FF,7F,7F,7F,7F
FF,FF,7F,7F,7F,7F
FB,FF,7F,BF,DF,EF

Does anyone have any ideas? Has anyone successfully used a nunchuck in PBP?

[Kamikaze47]

Ok, I worked it out. The main problem is I needed to use:

DEFINE I2C_HOLD 1

And then the following code works:

init:

i2cwrite i2c_clock_pin,i2c_data_pin,$A4,$F0,[$55]
pause 1
i2cwrite i2c_clock_pin,i2c_data_pin,$A4,$FB,[$00]
pause 1

main:

i2cwrite i2c_clock_pin,i2c_data_pin,$A4,[$00]
pause 1
i2cread i2c_clock_pin,i2c_data_pin,$A4,[STR datain/6]

[RFsolution]

Nice

Wondering what you are building for the WII ?

[Kamikaze47]

Nice

Wondering what you are building for the WII ?

I'm using the nunchuck for the 3-axis accelerometer. Next step is to interface a Wii Motion Plus too for the 3-axis gyroscope. I'm going to combine the two for a full 6 degrees of freedom sensor. The trickiest part of this will be the Kalman filter which involves some pretty heavy maths.

I'm doing all this because eventually i want to design and build one of these:

[Byte_Butcher]

I'm doing all this because eventually i want to design and build one of these:

Oh man.... I WANT one!


steve

[Kamikaze47]

Oh man.... I WANT one!

That was exactly my reaction. They are selling kits, but they are hugely expensive. I figured it would be more fun to design one from scratch anyway. I think i'll start with a 4 rotor version.