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Abstract. Spin coater usually applied in preparation of a thin layer in industrial coatings and advanced material functionalization in various applications. This paper reports the development of spin coater with a closed loop control system using ATMega8535 microcontroller. The thickness of the thin film layer depend on the rotation of spin coater in which usually controlled by open-loop type. In long-term utilization of the spin coater, the performance of the motor usually degraded and caused the speed of the rotation is no longer accurate. Therefore to resolve the drawback, a closeloop system is applied in currently developed spin coater. The speed range of the spin coater was designed in between 450-6000 rpm, equipped with user interface through push button and LCD display. The rotary encoder transducer was applied to sense the speed of the dc motor. The pulse width modulation (PWM) method is applied to control the speed of the dc motor. The performance of the control system were evaluated based on the applied voltage to the PWM driver (L298) versus speed of the motor and also the rise time, overshoot, and settling time of the control system. The result shows that in the setting of low speed (450 rpm), the settling time is very fast about 12 seconds and very high overshoot about 225 rpm, contrary for the high speed (5550 rpm) the setting time is 71 seconds and very low overshot about 30 rpm. In addition, to evaluate the stability of the mechanical system, the spin coater was tested to prepare a ZnO thin film in various speed of rotations and at various concentrations of the solution, i.e. 10 wt.% and 15 wt.%. It is concluded that the spin coater can be utilized for thin film coating after pass the maximum of the settling time (71 seconds). The currently developed spin coater produce a film with common characteristics of the spin coater where thicker film was obtained when higher concentration was used and thinner the film was obtained when higher speed of the rotation was applied.

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Abstrak. Pada kegiatan pengabdian pada masyarakat ini, telah berhasil didesain dan dibuat alat perangkap hama dengan basis cahaya UV yang sumber listriknya dari panel surya. Untuk memudahkan di dalam penggunaannya, alat telah dilengkapi dengan kontroler sehingga pengisian baterai dan penyalaan lampu dapat diatur waktunya secara otomatis. Berdasarkan hasil pengujian yang telah dilakukan, alat dapat berfungsi dengan baik, yaitu pengisian baterai berlangsung normal dan pada saat matahari terbenam, secara otomatis lampu UV menyala selama 10 jam. Setelah menyala 10 jam lampu UV akan mati secara otomatis untuk menghemat dan mengefisiensikan daya listrik yang digunakan. Berdasarkan hasil pengujian alat telah berfungsi dengan baik dan dapat menjebak hama yang biasa aktif di malam hari.Kata kunci : perangkap hama, cahaya UV, panel surya Abstract.In the community service activities has successfully designed and manufactured instrument for insect trapping using UV light with the electricity source from solar panels. For simplicity in use, the instrument has been equipped with a controller so the battery charging and the lighting can be switched automatically. Our experiments have resulted the instrument that well function, the charging of battery switch normally and at sunset and automatically turns on the UV lamp for 10 hours. The UV lamp turn on for 10 hours and then turn off automatically to save the electricity.Keywords : insect trapping, UV light, solar panels PendahuluanBudidaya tanaman padi merupakan hal yang sangat penting untuk menjamin ketahanan pangan masyarakat Indonesia. Padi atau beras telah menjadi sumber pangan pokok bagi masyarakat Indonesia. Salah satu masalah yang dapat mengurangi produksi padi adalah adanya serangan hama serangga atau wereng. Serangan hama wereng pada tanaman padi semakin ke sini semakin meningkat. Di beberapa wilayah di Jawa Barat seperti Karawang, Subang dan Majalengka, hama wereng telah merusak puluhan bahkan ratusan hektar sawah petani. Produksi sawah yang seharusnya 6.2 ton/ha, karena serangan hama wereng hanya mampu mencapai 5.4 ton/ha [1]. Petani mengalami kerugian dan ketersediaan pangan nasional pun terancam berkurang.Wereng adalah sebutan umum untuk serangga penghisap cairan tumbuhan dengan ukuran tubuh yang kecil. Terdapat beberapa jenis hama wereng, beberapa