Abstrak: Penelitian ini bertujuan untuk merancang dan mengembangkan alat pembelajaran berbasis mikroprosesor yang didukung oleh teknologi Internet of Things (IoT) di program studi Pendidikan Teknik Elektro, Fakultas Teknik, Universitas Negeri Medan. Alat ini dirancang untuk membantu mahasiswa memahami integrasi mikroprosesor dengan IoT, yang semakin relevan dalam konteks revolusi industri 4.0. Penelitian menggunakan metode Research and Development (R&D) dengan pendekatan ADDIE, yang mencakup tahap Analisis, Desain, Pengembangan, Implementasi, dan Evaluasi. Trainer ini menggunakan modul NodeMCU ESP8266 versi 5 yang dilengkapi dengan konektivitas Wi-Fi guna mendukung fungsi IoT. Validasi dilakukan oleh ahli materi dan media, serta diujicobakan secara terbatas pada mahasiswa. Hasil penelitian menunjukkan trainer ini sangat layak digunakan, dengan penilaian 86% dari ahli materi, 85,6% dari ahli media, serta kepuasan pengguna mencapai 85,4%. Selain itu, penggunaan trainer ini secara signifikan meningkatkan pemahaman konsep dan keterampilan praktis mahasiswa, terlihat dari kenaikan hasil post-test sebesar 32% dibandingkan pre-test. Kesimpulannya, trainer berbasis IoT ini efektif dan layak dijadikan media pembelajaran dalam pendidikan teknik. Kata Kunci: Trainer, Mikroprosesor, Internet of Things, Media Pembelajaran Abstract : This research aims to design and develop microprocessor-based learning tools supported by Internet of Things (IoT) technology in the Electrical Engineering Education study program, Faculty of Engineering, State University of Medan. This tool is designed to help students understand the integration of microprocessors with IoT, which is increasingly relevant in the context of the industrial revolution 4.0. This research uses the Research and Development (R&D) method with the ADDIE approach, which includes the stages of Analysis, Design, Development, Implementation, and Evaluation. This trainer uses a NodeMCU module ESP8266 version 5 equipped with Wi-Fi connectivity to support IoT functions. Validation is carried out by material and media experts, and tested on a limited basis to students. The results of the study show that this trainer is very feasible to use, with 86% assessment from material experts, 85.6% from media experts, and user satisfaction reaching 85.4%. In addition, the use of this trainer significantly improved students' understanding of practical concepts and skills, as evidenced by a 32% increase in post-test results compared to pre-tests. In conclusion, this IoT-based trainer is effective and worthy of being used as a learning medium in engineering education. Keywords: Trainer, Microprocessor, Internet of Things, Learning Media