I have updated the solar panel system design and corrected the wiring schematic errors.

Parts list

Solar Panel

https://www.amazon.com/NUZAMAS-Outdoor-Camping-Battery-Charger/dp/B075M4BWSX/

Servo

https://www.amazon.com/Phoneix-Micro-Helicopter-Airplanes-Steering/dp/B07D3L25H3/

Arduino

https://www.amazon.com/RoboGets-Compatible-ATmega328P-Microcontroller-Electronics/dp/B01N4LP86I/

LDR sensors

https://www.amazon.com/eBoot-Photoresistor-Sensitive-Resistor-Dependent/dp/B01N7V536K/

Bearings

Quantity 2: ID 10, OD 15, Width 2-3

Code sourced from Muhammad Aqib

https://circuitdigest.com/microcontroller-projects/arduino-solar-panel-tracker

Updated schematic – 2.1.19

Grounds can be sent directly to the Arduino.

Assembly instructions, new version will be slightly different in size.

Hot Glue the solar panel to the backing plate.

Insert LDRs into the shield mounting plate.

Slide solar back into servo holster (new version does not have 4 tabs sticking out).

Insert bearings x2 into the base plate.

Insert SG90 servo into base plate.

Press down upper assembly onto servo for press fit.

Wire everything into Arduino according to wiring diagram (grounds can be run directly to Arduino).

Test operation with a dark room and your phone light, there may be issues due to ambient light that I have attempted to address this with the redesign and will inform once testing is done.