No abstract

Abstrak-Pada penelitian ini telah dibuat sebuah alat untuk mengukur pH, suhu, dan kelembaban pada tanah berbasis mikrokontroler ATMega 328P. Pengukuran kelembaban tanah menggunakan sensor soil mouisture, Pengukuran pH tanah menggunakan elektroda dan pengukuran suhu tanah menggunakan sensor DS18B20. Mikrokontroler ATMega328P digunakan sebagai pengendali dan pemroses sinyal. Alat ini dilengkapi dengan sistem penyimpan data menggunakan SD Card sehingga mudah untuk pengambilan data hasil pengukuran.Tahapan penelitian meliputi proses perancangan, pembuatan dan pengujian alat. Hasil penelitian menunjukan bahwa kinerja alat ini mampu mengukur pH, kelembaban dan suhu tanah dengan error berturut-turut sebesar 2,68%, 1,53% dan 0,22% Kata kunci-sensor, pH, mikrokontroler, suhu , kelembaban tanah,

AbstrakTelah dibangun sebuah prototipe alat untuk mengukur ketinggian permukaan air laut berbasis mikrokontroler ATMega328. Sistem pengukuran berdasarkan prinsip kerja pelampung dan sensor inframerah sehingga dapat mengukur ketinggian permukaan air laut secara langsung. Instrumen ini dapat merekam hasil pengukuran ke dalam media penyimpanan data Multi Media Card (MMC). Tahapan penelitian meliputi proses perancangan, pembuatan dan pengujian alat. Alat ini dirancang untuk mengukur ketinggian air laut pada jarak 15 cm sampai dengan 110 cm dari sensor. Hasil eksperimen menunjukkan bahwa kinerja alat dipengaruhi oleh kestabilan gerak pelampung. Hasil pengujian alat memiliki nilai akurasi rata-rata sebesar 99,89 %.Kata kunci : sensor inframerah, mikrokontroler, ketinggian air laut.

A primer on the use of commercial off-the-shelf software in the development of low cost launch control systems AIP Conf.Abstract. Potentiostat is principal devices in modern electrochemical research especially in the investigation of mechanism reaction which associated with the redox chemistry reaction and other chemical phenomena. Several applications measurement is developed based on this tool such as measurement of sample concentrations, quality test of food and medicine, environmental monitoring and biosensors or development of a protein sensor. We have developed a low cost, simple and portable potentiostat with a relatively small dimension. TLC2264 op-amp and ATMEGA32 microcontroller is used to build controller circuit system. Range potential measurement of this tool is between -1600mV and +1600mV within frequency range 1Hz -1 kHz. The developed instrument has been tested for measuring samples using different voltammetry techniques, like cyclic, square wave, and linear sweep with relative error under 2.5%.

The prototype batteries was succesfully made by using activated carbon. This research aimed to examine the effect of pore size on the electrical properties of activated carbon which is used as a battery-making material. Activated carbon is synthesized using H3PO4 activator with concentration variations (mass/volume) of 5%, 10%, 15%, 20%, and 25%. The carbonization was carried out at 400 °C for 1 hour, while activation at 700 °C for 1 hour. The result showed, the pore size effect on the electrical properties of the activated carbon in the battery prototype, especially for the capacitance and internal resistance of the material which has a correlation of 90% and 90.2%, respectively. The sample with 25% H3PO4 has the best pore size of 5.43μm. As the pore size of the activated carbon increases, it has caused increased capacitance and decreased internal resistance of the material. With the pore size of 5.43μm, the capacitance is 5.88mF/g and the internal resistance of the material is 662.02Ω.