<![CDATA[High-power floodlights are commonly operated continuously at maximum brightness even though lighting needs vary by operating condition. This study designed and developed a 100 W COB LED floodlight with brightness control based on Pulse Width Modulation (PWM). The system used an ESP32 as the main controller, a potentiometer as the PWM input, an IRF540 MOSFET as the electronic switch, a boost converter as the lamp voltage supply, and DS18B20, LDR, and INA226 sensors to monitor temperature, light intensity, voltage, and current. Measurement data were shown on a 16x2 I2C LCD and sent to Google Spreadsheet when Wi-Fi was available, while the control and monitoring functions continued to operate during Wi-Fi disconnection. Testing was conducted through PWM variation, low-PWM operating threshold, Google Spreadsheet logging, fan cooling comparison, and oscilloscope observation of the MOSFET switching signal. The results show that the lamp responded at a very low PWM value, while stable light output was used at about 10% duty cycle. The LDR reading reached 4095 at 80-100% PWM. At 100% PWM, the measured voltage was 30.3 V and the current was 3.28 A, producing approximately 99.38 W. The fan reduced the temperature from 57.4 °C to 42.6 °C, with a difference of 14.8 °C. A 5 kHz PWM frequency produced a more stable light output than lower frequencies. Overall, the developed system was able to control brightness, monitor operating parameters, and record data automatically at prototype scale.]]>
