First thing to do is take it apart.

• Carefully remove the four screws in the base under the anti-skid rubbery circle

Now that it's apart, probe around and figure out what the chips do and what signals exist at which pins.

• Pin 5 of U2 has a 20 kHz PWM signal on it. As the brightness changes, it cycles through 20, 60, and 100 % duty cycle. When the LED is to be off, the pin is held low.
  • The white LED driver appears to be a switch-mode constant current design. The details of the design are not important here, since we know how to control it.
• Pins 2, 3, and 7 have a 2 kHz PWM signal, with duty cycle correlating to the following:
  • Pin 2: Blue PWM
  • Pin 3: Red PWM
  • Pin 7: Green PWM
  • It is interesting to see that these LEDs use current limiting resistors, with PWM being used as more of a voltage source here. Again, not going to dig in to it because I know how to control it.
• Pin 6 changes when the power LED changes. For my version, I won't be using this. In fact, I may even disable this entirely, since I'm not sure why a lamp needs an LED to indicate that it is on.
• Pin 4 is pulled low when the shroud is touched, so is the input from the cap sense interface chip, U5. Again, the implementation doesn't matter, all we care about is the signal.
• Pin 1 and 8 are power and gnd, respectively.

Sometimes I find my old Galaxy Note useful!