This project implements an embedded system based on the ATmega328P Xplained Mini development board. The purpose of the system is to orient a small solar panel toward the strongest light source using two servo motors and two KY-018 light sensors.

The project also includes an energy-monitoring subsystem. The solar panel charges a 1S2P battery pack through a voltage conditioning stage and a powerbank charging module. A battery level indicator is used to show the charge state of the battery pack. In addition, the system uses an external LED driven through PWM, with brightness adjusted according to the detected light intensity.

The initial idea started from combining a solar tracking mechanism with basic energy management, in order to demonstrate both embedded control and the use of harvested solar energy. The project is useful because it combines practical hardware interfacing with several important embedded concepts such as ADC, PWM, UART-style debugging concepts, and modular firmware design.

The system is split into two major subsystems:

• Energy subsystem
  • solar panel
  • voltage regulator / conditioning block
  • powerbank charging module
  • 1S2P 18650 battery pack
  • battery status indicator

• Control subsystem
  • ATmega328P Xplained Mini
  • 2 x KY-018 light sensors
  • 2 x servo motors
  • 1 x external LED with current-limiting resistor

The solar panel provides energy to the system through a voltage regulation / conditioning stage. The regulated output is connected to the charging input of the powerbank module. The powerbank module charges the 1S2P battery pack and also provides a stable 5V rail used to power the microcontroller board, the sensors, and the servo motors.

The ATmega328P Xplained Mini reads the analog outputs of the two KY-018 sensors and compares the light levels. Based on these values, the firmware controls the two servos in order to orient the solar panel toward the light source. The LED is controlled through PWM and its brightness reflects the measured light intensity.

A separate battery status module is connected to the battery pack and provides a visual indication of battery charge level.

• ATmega328P Xplained Mini development board
• 2 x MG90S servo motors
• 2 x KY-018 light sensor modules
• 1 x external LED
• 1 x 330 ohm resistor
• 1 x 5V / 1W solar panel
• 1 x voltage regulator / conditioning module for solar input
• 1 x 18650 powerbank charging module
• 1 x 1S2P 18650 battery pack
• 1 x battery status indicator module
• jumper wires and interconnection accessories

The system uses the ATmega328P Xplained Mini as the main controller. The powerbank module is responsible for battery charging and for generating a stable 5V output rail for the entire system.