Abstrak - Penelitian ini bertujuan mengembangkan modul ajar Mikrokontroler untuk meningkatkan pemahaman konsep dan keterampilan praktik mahasiswa melalui integrasi teori, simulasi, dan pembelajaran berbasis proyek. Permasalahan awal meliputi kesulitan mahasiswa memahami konsep dasar seperti register, timer, interrupt, komunikasi serial, serta kurangnya bahan ajar praktikum yang terstruktur. Pengembangan modul mengikuti model ADDIE, mencakup analisis kebutuhan, perancangan, pengembangan, implementasi, dan evaluasi.Modul dirancang dengan materi pengenalan Arduino, pemrograman C bertahap, simulasi TinkerCad/Proteus, praktikum langkah-demi-langkah, serta proyek akhir berbasis PjBL. Hasil validasi ahli menunjukkan kategori sangat layak pada aspek materi, media, dan pedagogis. Uji coba pada 35 mahasiswa menunjukkan peningkatan signifikan pada hasil belajar, dengan nilai rata-rata meningkat dari 48,6 (pretest) menjadi 82,4 (posttest) dan N-gain 0,69. Selain itu, 89% mahasiswa dapat menyelesaikan sebagian besar praktikum dan 82% berhasil menuntaskan proyek akhir. Tingkat kepuasan mahasiswa juga tinggi, khususnya terhadap kejelasan instruksi, contoh kode, dan dukungan simulasi.Modul terbukti efektif meningkatkan pemahaman konsep dan keterampilan praktik, termasuk wiring rangkaian, debugging, serta penguasaan bahasa C. Keterbatasan penelitian mencakup jumlah sampel kecil dan fokus pada platform Arduino. Secara keseluruhan, modul layak diterapkan dan dapat dikembangkan lebih lanjut pada konteks pembelajaran yang lebih luas.Kata kunci: Modul Ajar; Mikrokontroler; Arduino; Project-Based Learning; Simulasi; Pembelajaran Praktikum; Abstract - This study develops a microcontroller teaching module aimed at improving students’ conceptual understanding and practical skills through the integration of theory, simulation, and project-based learning. Students initially faced difficulties with core concepts such as registers, timers, interrupts, and serial communication, alongside limited access to structured practical materials. The module was developed using the ADDIE model, covering needs analysis, design, development, implementation, and evaluation. The final module includes introductory Arduino content, step-by-step C programming, TinkerCad/Proteus simulations, guided practical activities, and a project-based final task. Expert validation rated the module as highly feasible in terms of material quality, media design, and pedagogical suitability. A classroom trial with 35 students demonstrated substantial learning gains, with average scores improving from 48.6 (pretest) to 82.4 (posttest) and an N-gain of 0.69. Furthermore, 89% of students completed most practical tasks, and 82% successfully completed the final project. Student satisfaction was high, especially regarding instructional clarity, code examples, and simulation support. The module effectively enhanced students’ conceptual understanding and practical competencies, including circuit wiring, debugging, and C programming. Study limitations include a small sample size and reliance on the Arduino platform. Overall, the module is feasible for implementation and can be expanded for broader learning contexts.Keywords: Teaching Modules; Microcontrollers; Arduino; Project-Based Learning; Simulations; Practical Learning;