1：Experimental Design and Method Selection:

The study proposed an IoT-based monitoring system for solar PV systems, utilizing Arduino ATMega2560 as the microcontroller, ESP8266 as the wireless transceiver, and Thingspeak as the IoT platform. A smartphone application was developed using MIT App Inventor for data display.

2：Sample Selection and Data Sources:

A monocyrtalline solar photovoltaic panel connected to a Maximum Power Point Tracking (MPPT) solar charge controller was used, with a VRLA battery as storage. Data was collected over three consecutive days from 8 am to 4 pm.

3：List of Experimental Equipment and Materials:

Equipment included a solar PV panel, MPPT solar charge controller, VRLA battery, voltage divider circuit, ACS712 current sensor, LM35 temperature sensor, GY-49 MAX44009 light intensity sensor, Arduino Mega (ATMega2560), and NodeMCU ESP

4：Experimental Procedures and Operational Workflow:

82 Sensors were calibrated before data collection. The system measured voltage, current, temperature, and light intensity, with data processed by Arduino and sent to Thingspeak via ESP8266. Data was visualized on a smartphone app.

5：Data was visualized on a smartphone app. Data Analysis Methods:

5. Data Analysis Methods: Data accuracy was assessed through calibration, calculating mean and standard deviation of percentage differences from standard measuring instruments.