<![CDATA[Light energy transmission is one of the topics in junior high school science (Physics) that potentially causes comprehension difficulties due to its abstract nature when delivered solely through theoretical instruction. A literature review of Arduino-based studies reveals two gaps: first, some studies focused only on measuring light intensity without examining light energy transmission through specific media; second, studies that measured transmission through transparent materials remained limited to ideal laboratory conditions and had not integrated assessments of students' conceptual understanding. This study aimed to develop a light energy transmission measuring teaching aid based on the Arduino ESP32 type, programmed using the Arduino IDE. The ESP32 was selected due to its advantages over conventional Arduino, integrated Wi-Fi and Bluetooth, enabling more accurate sensor readings and real-time data display. The novelty of this study lies in its focus on light energy transmission, utilization of ESP32, an LED flashlight as a contextual light source, testing on nako glass and no medium conditions, and direct assessment of students' conceptual understanding within a single integrated design. The method used in this study is the Research and Development (R&D) method with the ADDIE model design, conducted at SMP Negeri 7 Sigi involving 21 eighth-grade students of class VIII A. Data were analyzed using the N-Gain formula. The results showed an N-Gain score of 0.58 which falls in the moderate category, indicating an improvement in students' conceptual understanding after participating in the learning process by applying teaching aids in the learning.]]>
