How many levels are there for the tanks game in Wii Play

So the Wii Joystick uses a Blue Tooth interface which is a little different than the N64 controller. As a result this answer deals more with the latter than the former.

The N64 controller uses a single transmission wire on which it encodes bits to send signals back to the N64 console. To accomplish this bits are encoded on that wire as follows:

This encoding can then be used to multiplex the connection and allow 32 bit communication. In the case of the N64 controller these bits are encoded thus:

0   A
1   B
2   Z
3   Start
4   Directional Up
5   Directional Down
6   Directional Left
7   Directional Right
8   unknown (always 0)
9   unknown (always 0)
10  L
11  R
12  C Up
13  C Down
14  C Left
15  C Right

With the remaining 16 bits being used for the Analog Joystick (providing 8 degrees of control).

More over, certain codes are transmitted for specialized function:

To Init: send 03 80 01 followed by 34 80's
To Start Rumble: 03 c0 1b followed by 32 01's
To Stop Rumble: 03 c0 1b followed by 32 00's

You can find more information in this vein here

When on the shore where the treasure is, pull out your telescopic lens and browse the shore around the X on your map (marking the treasure's location) until you see your target. Then attempt to land on the shore.