I’ve been having great fun with the Arduino Uno microcontroller board.  Here I’ve got the Arduino using a shift register to light up a 7-segment display output.

This device is reading the output voltage of the solar panel out to a 2-digit, 7-segment display.  So basically it’s a light meter!  The real fun of this little project has been writing the driver in C++ Arduino-code to run the shift register.  Magic!