Electrical System:

The photoresistors have a varying resistance based on the amount of sunlight shining on them.  When combined in series with a standard resistor, the photoresistor provides a varying voltage drop across the photoresistor.  This voltage drop can be measured by the handy board and then translated into a corresponding integer from 0-255.  Depending on the number interpreted by the handy board, the blinds will open and close accordingly. The photoresistor sensor wiring makes use of the on-board 47K ohm resistor that connects the sensor signal line to +5V

Knowing that photoresistors are small and that a different amount of sunlight falls on different areas of the window, there will be four photoresistors taking readings and the average light intensity computed.  This average light intensity will be the amount that controls the blinds. 

Toggle A controls the AUTO/MANUAL functionality of the tilt mechanism.
Buttons A1 and A2 control the direction of tilt when in MANUAL mode.
The readings from the photoresistors are taken into account when in AUTO mode.

Toggle B controls the ON/OFF functionality of the telescoping mechanism.
Buttons B1 and B2 control the up and down telescoping of the blinds when toggle B is set to ON.