Magnet Detector Simulation Tool Based on Microcontroller ATMEGA 8535, Diploma III, Electronic Engineering, Department of Electrical Engineering, Faculty of Engineering, University of Jakarta. Magnet Detector Simulation Tool Based on Microcontroller ATMEGA 8535, using a series of sensors and infrared photodiodes and output sensor magnet DC motors. The Magnet Detector Simulation Tool Based on Microcontroller ATMEGA 8535, through some process that has been carried out, including the manufacture of electronic circuits and manufacture of mechanical parts. Further tests performed on each set of systems, from the power supply, the minimum system, magnetic sensors and photodiode. From the experimental results, it can be obtained that the tool has been working in accordance with the job description of a device that is controlled using a microcontroller is programmed using software ATMega8535 Code Vison AVR C Compiler. Simulasi Alat Pendeteksi Magnet Berbasis Mikrokontroler ATMega 8535, D3 Teknik Elektronika, Jurusan Teknik Elektro, Fakultas Teknik, Universitas Negeri Jakarta. Simulasi Alat Pendeteksi Magnet Berbasis Mikrokontroler ATMega 8535 mikrokontroler menggunakan serangkaian sensor dan fotodioda inframerah dan output sensor magnet motor DC. Simulasi Alat Pendeteksi Magnet Berbasis Mikrokontroler ATMega 8535, melalui beberapa proses yang dilakukan, termasuk pembuatan sirkuit elektronik dan pembuatan bagian-bagian mekanik pada alat. Pengujian lebih lanjut dilakukan pada setiap rangkaian sistem dilakukan, mulai dari power supply, sistem minimum, sismin, sensor magnetik dan fotodioda. Dari hasil percobaan dapat diperoleh bahwa alat untuk bekerja sesuai dengan job description dari alat yang akan dikontrol menggunakan mikrokontroler ATMega8535 diprogram menggunakan software Code Vison AVR C Compiler.