Abstract
The rapid development of Internet of Things (IoT) technology requires practical learning media that can help vocational students understand the integration of sensors, actuators, microcontrollers, and remote communication systems. This study aims to design and evaluate an ESP32-based IoT trainer kit integrated with Telegram as a remote monitoring and control platform for microcontroller and IoT learning. The development process followed a waterfall model consisting of requirement analysis, system design, implementation, and functional testing. The trainer kit uses an ESP32 microcontroller as the central controller and integrates several input modules, including an HC-SR04 ultrasonic sensor, DHT22 temperature and humidity sensor, passive infrared sensor, light-dependent resistor, MQ-2 gas sensor, and RC522 RFID module. The output modules consist of a 16x2 LCD, LED indicators, buzzer, servo motor, relay, and solenoid door lock. Functional testing showed that all modules operated according to the designed logic. The RFID module successfully read cards at a distance of 0–3 cm, the ultrasonic sensor triggered servo movement when the object distance was less than 6 cm, the passive infrared sensor produced an output change from approximately 0 V to 3.1 V when motion was detected, and the MQ-2 sensor activated the buzzer when the gas reading exceeded the threshold value of 800. The system also displayed sensor data on the LCD and delivered event notifications through Telegram. These results indicate that the proposed trainer kit is feasible as an interactive learning medium for ESP32-based IoT practice.
Keywords - ESP32, Internet of Things, Telegram, Trainer Kit, Vocational Learning.