This page will host PCB files and datasheets for the most current Solarduino design.
The Solarduino V2 is a prototype model. No claims are made regarding the effectiveness or functionality of these designs 
Soarduino V2 Schematic (pdf)
Solarduino PCB files (Design Spark, zip)
Current Firmware T_solar (9Kb zip)
DATASHEETS:
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TC54 Voltage Detector
MCP4551 Digital Potentiometer
TC75501 Voltage Regulator
Avago Ambient Light Sensor
DS3231 Real Time Clock