update( ) first pauses for a millisecond to let things settle a bit.
Then we request six bytes from the Nunchuk,
calling Wire.requestFrom( ).
Thisdoes not actually return the bytes, but we have to read them in a loop
and fill our buffer.
Wire.available( ) returns the number of bytes that are
available on the data bus, and Wire.
receive( ) returns the current byte.
We cannot use the bytes we get from the Nunchuk directly, because the
controller obfuscates them a bit.
“Decrypting” them is easy as you can
see in decode_byte( ).