By the advise from How to connect wii balance board with android
Through 0x32,
According to data pattern below , Byte no. 0 and 1 is serve for core buttons. Another 8 bytes left is for the extension (Balance Board)
From my observation, Bit no. 2,4,6,8 are change for a little bit swing (Ex. bit no. 2's normal value without any pressure is 49, and when I stand on the board, it changed to 50,51,52,... But the other (Bit no. 3,5,7,9 is too much swing. (Ex. from -127 to 127 (for every bit))
I have try with 2 balance board, the data value when no any pressure is different
This picture below show about data(in hex) transmit captured from Logcat
http://image.ohozaa.com/i/fcd/gpWyHN.png
**** As you see, value from bit no. 2,4,6,8 not changed, but 3,5,7,9 is changing a little evenif there no pressure on it.
**** At line number 11, through port 0x21, Is it calibration data ?
So, the next question is, - What is the meaning of each bit of these data. - How to translate it to weight and location of Center of Gravity ?
Please help! I have no any clue about this from tried for 1 weeks, and deadline is coming T_T
** addition picture about data in decimal value when standing and not stand on it in the comment below