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/Extension_Controllers#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: http://www.youtube.com/watch?v=gvH2f-AewX8

[Byte_Butcher]

I'm doing all this because eventually i want to design and build one of these: http://www.youtube.com/watch?v=gvH2f-AewX8

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.

[Byte_Butcher]

That was exactly my reaction. They are selling kits, but they are hugely expensive.

Expensive AND out of stock.

Please keep use posted on your progress! (Photos, video, working code, :))



steve

[Kamikaze47]

Please keep use posted on your progress! (Photos, video, working code, :))

Will do, but it's going to be slow work.

The Kalman Filter to combine the accelerometer and gyroscope data into useful tilt measurements is what i'm researching at the moment. It's going to be tricky in PBP without floating point math.

[yatyas72]

I just started messing with the Wii Nunchuk and WMP to do a project similar to the MultiWii on RCGroups. I am just in the beginning stages of the project and was wondering if you would share any code for talking with the Nunchuk? My plan is to finish up the soldering of the connections tonight and hopefully if all goes well I'll be talking with the Nunchuk. I'm going to try and convert code from these sites http://nunchuckmouse.blogspot.com/ and http://www.musclera.com/wii-nunchuk-demonstration/ to PBP in order to accomplish this. It seems pretty basic but I've never messed with I2C. I figure if you have a heads up on how to do this any help would be greatly appreciated.
Currently I have a 18F2550 CDC/USB connection talking to a VB6 program that I use to send command to turn on and off relays, LED's and move servos around so I'm hoping I can just expand my program to receive the I2C info once I get it to talk and send data down I plan to move forward converting the Arduino code to PBP.
I also just bought a BTM-182 module from sparkfun to start messing with designing my own controller instead of using an RC remote. If anyone has experience using these or other bluetooth modules help there is appreciated also.
I am a Mechanical Engineer for a company called Lite Machines, I do all of the tool and die and fixture design stuff and dabble in programming. Check out http://www.litemachines.com we make UAV's for the military so all of this is not out of reach for me just that I'm limited on time and thought maybe we could get a thread started like this one http://www.rcgroups.com/forums/showthread.php?t=1332876.

Thanks,
Larry

[yatyas72]

BTW- This is not in anyway work related. Just something I thought I could do at home that might also get my 9 year old son involved in electronics also.

Thanks,
Larry

[gadelhas]

Hi;

I made this program one year ago. This program aquires receive the data from Nunchuck and then acording to some "if", some data is sent to the serial port.
Maybe you can see how it works, and use it with some modification.

Try to find the label "Nunchuck" at the end of the program, that is the routine that receive the data from the nunchuck.


Code



'************************************************* ***************
'* Name : NUNCHUCK RF.BAS *
'* Author : [Hugo Oliveira] *
'* Notice : Copyright (c) 2010 *
'* : All Rights Reserved *
'* Date : 09-07-2010 *
'* Version : 1.0 *
'* Notes : BreadBoard *
'* : PIC16F628A *
'************************************************* ***************
include "modedefs.bas"
DEFINE OSC 4
DEFINE I2C_HOLD 1

@ DEVICE pic16F628A, INTOSC_OSC_NOCLKOUT
@ DEVICE pic16F628A, WDT_OFF
@ DEVICE pic16F628A, PWRT_OFF
@ DEVICE pic16F628A, MCLR_OFF
@ DEVICE pic16F628A, BOD_OFF
@ DEVICE pic16F628A, LVP_OFF
@ DEVICE pic16F628A, CPD_OFF
@ DEVICE pic16F628A, PROTECT_OFF


' VARIÁVEIS
' ================================================== ==================
Jx var byte
Jy var byte
Ax var Byte
Ay var byte
BE var bit
BD var bit
buffer var byte[6]

' REGISTOS PINOUT 1 = IN; 0 = OUT
' ================================================== ==================
'76543210
TRISA = %00000000
TRISB = %00000010
CMCON = 7
VRCON = 0
' NOMES PINOUT
' ================================================== ==================
LED VAR PORTA.1
TX Var PORTB.2
RX VAR PORTB.1
SDA var PORTB.4
SCL var PORTB.5
' DEFENIÇÕES
' ================================================== ==================
DEFINE DEBUG_REG PORTB
DEFINE DEBUG_BIT 2
DEFINE DEBUG_BAUD 19200
DEFINE DEBUG_MODE 0

' INICIO PROGRAMA
' ================================================== ==================
Start:
HIGH LED
PAUSE 500
LOW LED
PAUSE 500
HIGH LED
PAUSE 500
LOW LED
PAUSE 500
HIGH LED

Main:

GOSUB NUNCHUCK
' JoyStick Eixo X
' ================================================== ==================
if JX>70 and JX<=100 then
'SEROUT TX,T9600,["%TE"]
DEBUG "%TE"
pause 20
endif

if JX>0 and JX<=70 then
'SEROUT TX,T9600,["%TE1"]
DEBUG "%TE1"
pause 20
endif

if Jx>180 and Jx<210 then
'SEROUT TX,T9600,["%TD"]
DEBUG "%TD"
pause 20
endif

if Jx>=210 then
'SEROUT TX,T9600,["%TD1"]
DEBUG "%TD1"
pause 20
endif
' JoyStick Eixo Y
' ================================================== ==================
if JY>70 and JY<=100 then
'SEROUT TX,T9600,["%TB"]
DEBUG "%TB"
pause 20
endif

if JY>0 and JY<=70 then
'SEROUT TX,T9600,["%TB1"]
DEBUG "%TB1"
pause 20
endif

if Jy>180 and Jy<210 then
'SEROUT TX,T9600,["%TC"]
DEBUG "%TC"
pause 20
endif

if Jy>=210 then
'SEROUT TX,T9600,["%TC1"]
DEBUG "%TC1"
pause 20
endif
' Axis - Eixo X
' ================================================== ==================
if Ax<100 then
'SEROUT TX,T9600,["%TE2"]
DEBUG "%TE2"
pause 20
endif

if Ax>140 then
'SEROUT TX,T9600,["%TD2"]
DEBUG "%TD2"
pause 20
endif
' Axis - Eixo Y
' ================================================== ==================
if Ay<110 then
'SEROUT TX,T9600,["%TB2"]
DEBUG "%TB2"
pause 20
endif

if Ay>140 then
'SEROUT TX,T9600,["%TC2"]
DEBUG "%TC2"
pause 20
endif
' Botões
' ================================================== ==================
IF BE = 0 then
'SEROUT TX,T9600,["%RL1"]
DEBUG "%RL1"
pause 80
endif

IF BD = 0 then
'SEROUT TX,T9600,["%RD1"]
DEBUG "%RD1"
pause 80
endif
goto Main
' SUB ROTINA - LEITURA DADOS NUNCHUK
' ================================================== ==================
NUNCHUCK:
i2cwrite sda,scl,$A4,$40,[$00]
pause 10
i2cwrite sda,scl,$A4,[$00]
pause 10
i2cread sda,scl,$A5,[STR buffer\6]
pause 10

Jx=(buffer[0] ^ $17)+ $17
Jy=(buffer[1] ^ $17)+ $17
Ax=(buffer[2] ^ $17)+ $17
Ay=(buffer[3] ^ $17)+ $17
buffer[5]=((buffer[5] ^ $17)+ $17 )

if (buffer[5] & $01) <> 0 then
BE=1
else
BE=0
endif

if (buffer[5] & $02) <> 0 then
BD=1
else
BD=0
endif

RETURN
END

[yatyas72]

Thanks Gadelhas,
I finished wiring up the Wii components last night and will hopefully get a chance to play with the I2C this weekend. I looked through your code and it seems as straight forward as I thought. I will post here or start a new thread once I get this project going.

Larry

[gadelhas]

ok, post your results when you have them!