The systems will be implemented in the following way:

• The solar panel will be connected to the input of a LiPo battery charge controller.

• Our current charge controller takes a USB C input, and the solar panel outputs 6 volts at its peak, decreasing with decreased light intensity, so a voltage regulator is required between the two.

• The battery will be connected to the charge controller using a JST2.0 connection.

• The charge controller output is USB A, and will split to charge the phone and power the display system.

• To charge the phone, currently a small USB to lightning wire is being used.

• The display system consists of an Arduino ESP32 Nano and an OLED display, which will display metrics such as battery life.

• All these components are implemented and housed in a 3D printed case

The assembled prototype is pictured below