Jurnal SPEKTRUM is peer review journal, published four times a year by the Department of Electrical Engineering, Faculty of Engineering, Universitas Udayana. This journal discusses the scientific works containing results of research in the field of electrical, include: power systems, telecommunications, computers, informatics controls, and electronics. Authors are expected to include original scientific papers in accordance with the scope of the discussion of this journal including all aspects of the theory and practice are used. p-ISSN: 2302-3163 e-ISSN: 2684-9186 Member of: Sinta S4
RANCANG BANGUN SISTEM IRIGASI OTOMATIS DENGAN PEMANFAATAN ENERGI SURYA PADA TANAMAN BUAH NAGA
Budidaya buah naga sangat bergantung pada pengelolaan irigasi yang tepat. Kendala biaya operasional dan inefisiensi pada sistem penyiraman manual bertenaga diesel di Desa Mengwitani mendorong perlunya inovasi teknologi. Penelitian ini bertujuan merancang dan membangun sistem irigasi otomatis berbasis Internet of Things (IoT), dengan catu daya dari energi matahari (PLTS). Pemantauan dan kendali dilakukan dengan aplikasi telegram dan Google Spreadsheet. Sistem ini dikendalikan oleh ESP32 yang diantarmukakan dengan sensor-sensor berupa sensor kelembapan tanah kapasitif, sensor suhu (DHT22), sensor ultrasonik (HC-SR04), sensor arus dan tegangan dc (INA219). Pengairan menggunakan pompa submersible DC dan solenoid valve, disuplai oleh panel surya monocrystalline 50 Wp dan baterai LiFePO4 12V 30Ah (direct DC to DC). Hasil pengujian selama tujuh hari mengonfirmasi sistem beroperasi sesuai rancangan. Sistem menyalurkan 8,5 liter air/pohon per siklus (durasi 70 menit, debit 313,2 liter/jam) untuk meningkatkan kelembapan tanah dari 69% menjadi 89%. Pompa DC mengonsumsi energi 15,96 Wh dan menurunkan State of Charge (SoC) baterai sebesar 4,57% selama 19 menit beroperasi. Secara keseluruhan, integrasi perangkat keras dan pemantauan jarak jauh untuk tanaman buah naga sudah berhasil direalisasikan sesuai dengan tujuan penelitian Kata kunci : Buah Naga, IoT, ESP32, irigasi otomatis, PLTS, Bot Telegram, kelembapan tanah
PERENCANAAN SUPLAI DAYA DI RUMAH SAKIT AMERTA HUSADHA
As vital facilities, hospitals require a highly reliable and secure electrical power supply to ensure uninterrupted 24-hour operations, specifically in critical care zones such as operating theaters and Intensive Care Units (ICUs). Interruptions in power supply can lead to fatal outcomes. This study aims to design an electrical installation system that is optimal, efficient, and compliant with safety standards outlined in the Minister of Health Regulation No. 24 of 2016 and the General Electrical Installation Requirements (PUIL) 2011. Utilizing a quantitative descriptive method with a case study approach, data were collected via building blueprint documentation and field observations. The analysis encompassed installed load calculations, the selection of protection devices, and the determination of technical specifications for main and backup power systems. The findings reveal a total planned peak load of 1,549.7 kVA. Consequently, the installation of two 1,250 kVA transformers is recommended. The study concludes that reliability and safety must be prioritized over cost efficiency in hospital power planning. The proposed design is intended to serve as a technical guideline for establishing robust electrical systems that support the critical functions of healthcare facilities.
ANALISIS PENGARUH RISE TIME PADA LINE CODING RZ DAN NRZ PADA JARINGAN OPTIK
Line coding is a process of converting digital data into electrical signals so that they can be transmitted in a fiber optic network. Commonly used line coding is NRZ and RZ. Line coding characteristics are determined by the selection of Rectangular shape, Amplitude, Bias, Position, Rise Time and Fall time. The rise time of a signal is defined as the time required for the signal to change from 10% to 90% of the maximum value. In this study, the effect of increasing the rise time value on RZ and NRZ line coding was observed compared to Q Factor and BER. The rise time value starts from 0.05 bits with an increase of 0.05 until it reaches a value of 1 bit. The results obtained show a change in the signal shape from the edial form at a rise time of 0.05 bits to a non-edial form at a value of 1 bit. RZ line coding shows no significant change in Q Factor and BER from changes in rise time values, but NRZ line coding shows a decrease in Q Factor by 10.57% and BER by 80.9%.
ANALISIS TINGKAT KEMATANGAN KEAMANAN INFORMASI DATA KEPEGAWAIAN BERDASARKAN KERANGKA KERJA ISO/IEC 27001:2022
Keamanan data adalah masalah kritis ketika menangani informasi pribadi karyawan, terutama jika mereka bekerja untuk organisasi pemerintah. Namun, masih banyak organisasi yang tidak memiliki kebijakan formal tentang bagaimana menerapkan Sistem Manajemen Keamanan Informasi (SMKI). Tujuan dari studi ini adalah untuk menilai tingkat kematangan SMKI yang diterapkan dalam mengelola data pribadi pegawai dan untuk mengidentifikasi kontrol untuk meningkatkan tingkat kematangan. Kuesioner, wawancara, dan observasi digunakan untuk mengumpulkan data tentang pengelolaan data pribadi. Penilaian tingkat kematangan dilakukan pada 21 kontrol sesuai dengan ISO/IEC 27001:2022. Temuan survei mencerminkan tingkat kematangan keseluruhan sebesar 3,6, menunjukkan bahwa sebagian besar kontrol sudah ada. Namun, dari hasil wawancara dan observasi menunjukkan beberapa kesenjangan terutama berkaitan dengan penyamaran data, kebijakan keamanan informasi, dan pemantauan aktivitas. Diharapkan bahwa temuan ini dapat digunakan untuk memberikan dasar bagi pembuatan kebijakan keamanan informasi dan peningkatan kemampuan sumber daya manusia oleh organisasi.
PERANCANGAN DAN KUALITAS LAYANAN JARINGAN FTTH (FIBER TO THE HOME) GPON DI DAERAH SUKAWATI
Teknologi Gigabit Passive Optical Network (GPON) adalah teknologi jaringan berbasis serat optik yang digunakan untuk mentransmisikan data melalui sinyal cahaya. Dengan menggabungkan kapasitas besar serat optik, pemanfaatan gelombang cahaya, dan sistem berbagi jaringan, GPON dapat mencapai kecepatan transfer data hingga tingkat gigabit ke rumah dan gedung yang terhubung. Teknologi ini digunakan dalam layanan akses broadband seperti Fiber to the Home (FTTH), yang memungkinkan penyedia layanan untuk memberikan koneksi internet berkecepatan tinggi kepada pengguna mereka. Dalam penelitian ini, daerah Sukawati dipilih sebagai lokasi perancangan FTTH karena kebutuhan layanan jaringan internet yang belum terpenuhi dari 3.000 pelanggan yang tinggal di wilayah tersebut. Hasil survei tentang jumlah rumah, tiang tiang yang telah dipasang, dan jumlah pengguna yang memiliki koneksi internet. Penelitian ini menggunakan metode perhitungan matematis dan metode simulasi dengan menggunakan program OptiSystem. Setelah dihitung, nilai redaman total untuk ODC FA -20 dBm dan ODC FB -19 dBm ditemukan, masing-masing 20,255 dB dan 20,537 dB, yang masih di bawah batas redaman total standar ITU-T sebesar 28 dB. Hasil ini menunjukkan bahwa jaringan memiliki kemampuan untuk memberikan layanan pelanggan yang luar biasa.
I Gusti Agung Komang Diafari Djuni Hartawan
PEMBERIAN ZAT ADITIF SEBAGAI MEDIA PENURUNAN TAHANAN JENIS TANAH LOKASI GARDU DISTRIBUSI DI PESISIR TANAH LOT
Penyulang Pandak bersumber dari GIS Tanah Lot merupakan jaringan distribusi tegangan menengah 20 kV di wilayah Kabupaten Tabanan. Penyulang ini memiliki topologi jaringan radial membentang luas untuk mensuplai 41 gardu distribusi dengan total kapasitas terpasan mencapai 6.175 kVA. Untuk menjaga keamanan gardu distribusi tersebut dibutuhkan pembuatan sistem pembumian. Tipe sistem pembumiannya tergantung dari tekstur tanahnya. Tekstur tanah Penyulang Pandak didominasi oleh tanah lempung, namun beberapa lokasi gardu distribusinya berlokasi pada tekstur tanah pasir berdebu yang memiliki nilai tahanan jenis tanah lebih besar, sehingga membutuhkan perbedaan tipe pembumian, apalagi lokasi gardu distribusinya sangat sempit rata-rata berukuran 2mx2m. Tujuan penelitian ini untuk mengetahui sistem pembumian yang digunakan pada gardu distribusi khusus pada lokasi gardu distribusi pesisir Tanah Lot yang memiliki tekstur tanah berpasir. Metode yang digunakan dalam penelitian ini adalah metode kuantitatif deskriptif. Berdasarkan hasil analisis didapatkan hasil dengan penambahan zat aditif gypsum pada lokasi gardu distribusi Penyulang Pandak di pesisir Tanah Lot dengan tekstur tanah pasir berdebu terjadi penurunan tahanan jenis tanah sebesar 36,7%, penghematan pemakaian elektroda batang sebesar 50% serta memperkecil dimensi tipe sistem pembumiannya dan cocok untuk lokasi gardu distribusi dengan lahan yang sempit. Kata kunci: Pembumian, Gardu Distribusi, Pesisir Tanah Lot.
ANALISIS KINERJA KODE BOSE CHAUDHURI HOCQUENGHEM PADA DIRECT SEQUENCE SPREAD SPECTRUM PADA KANAL FREKUENSI SELECTIVE FADING
This study aims to analyze the performance of Bose Chaudhuri–Hocquenghem (BCH) coding (7,4) in a Direct Sequence Spread Spectrum (DSSS) system using Pseudo Noise (PN) spreading code, under frequency selective fading and white Gaussian noise (AWGN) channel conditions. Simulations were performed using MATLAB Simulink to compare the system performance against Bit Error Rate (BER) at various values of bit energy to noise power density (Eb/No). The simulation results show that the use of BCH generally improves system performance by significantly reducing the BER value. At high Eb/No, the performance of PN + BCH is slightly better. This indicates that the effectiveness of signal coding and spreading is strongly influenced by channel conditions and noise levels. Code length, spreading type, and error correction method play an important role in optimizing digital communication performance.
PERANCANGAN DIRECT CHARGING SEPEDA MOTOR LISTRIK DAN PEMILIHAN LOKASI PEMASANGAN DI BALI SELATAN
Bali is one of the regions in Indonesia at the forefront of the transition toward clean energy. One of the key steps to achieving this goal is the shift to electric vehicles (EVs). Therefore, the design of electric vehicle charging stations is a crucial factor in ensuring a smooth transition. Charging stations must be strategically located to provide easy access for users, and their planning must comply with existing regulations. One type of charging station is the Public Electric Vehicle Charging Station (SPKLU). However, most SPKLUs are focused on electric cars, whereas the use of electric motorcycles is far more widespread. For this reason, this study focuses on the design of a direct charging system for electric motorcycles, which can be connected directly to the vehicles. The design process includes both 3D modeling and the electrical layout. The selection of a suitable location will be carried out using the Analytic Hierarchy Process (AHP) to determine the optimal site in the South Bali area
PERANCANGAN SPKLU SEPEDA MOTOR LISTRIK DAN PEMILIHAN LOKASI PEMASANGAN DI BALI SELATAN
Indonesia is currently in a transition toward clean energy. Therefore, accelerating the adoption of Electric Vehicles (EVs) as a replacement for fossil-fueled vehicles has become a strategic step that is being actively promoted. To support this, the availability of adequate infrastructure is a key factor, with charging stations serving as the main infrastructure for electric vehicles. For optimal operation, the development of charging stations requires proper location selection and design. This study focuses on the design and location selection of Public Electric Vehicle Charging Stations (SPKLU) intended for electric motorcycles in the South Bali region. The design features a three-dimensional model of the charging station, along with its corresponding electrical plan. Meanwhile, location selection is carried out using the Analytical Hierarchy Process (AHP) method by evaluating potential sites. The outcome of this study is the identification of the best location for installing the SPKLU, accompanied by design suited to the site’s characteristics and the SPKLU’s electrical design. It is expected that this work can serve as a study and reference for further development to accelerate the adoption of electric vehicles in Bali.
PENERAPAN TEKNOLOGI TEPAT GUNAALAT SIRAT (SPLIT DAN IRAT) SEBAGAI UPAYA PEMERDAYAAN PENGRAJIN BAMBU DI DESA KAYUBIHI
Kayubihi Village, Bangli District, Bali, has great potential in the bamboo craft industry because 15% of its population works as craftsmen. However, limited traditional tools lead to low productivity and low quality results. This study aims to analyze the effectiveness of the use of the SIRAT (Split and Irat) tool in increasing the efficiency and productivity of craftsmen. The research method used is descriptive quantitative through structured observation and questionnaires. The results showed that the SIRAT tool can reduce processing time, from 35 seconds to 2 seconds in the split process, and from 73 seconds to 50 seconds in the irat process. Average split production increased from 0.57–1.42 stems per day to 1.85–3.42 stems, while irat production increased from 50.29–125.71 stems to 163.43–301.71 stems per day, or equivalent to an increase of 130%–225%. In addition, this tool produces more uniform bamboo sizes, reduces labor load, and reduces the risk of work accidents. Thus, the application of the SIRAT tool has proven effective in increasing productivity and quality of results, while also supporting Kayubihi Village as a bamboo craft center.
EVALUASI KUALITAS TEKNIS SISTEM INFORMASI ADMINISTRASI COASS MENGGUNAKAN GOOGLE LIGHTHOUSE
The successful adoption of an information system is highly dependent on its technical quality, including performance, accessibility, adherence to Best Practices, and SEO compliance. This study aims to evaluate the technical quality of a web-based information system for Coass (clinical internship) administration using Google Lighthouse. The audit was conducted on three key user interfaces: the Admin, Doctor, and Student Dashboards. The evaluation focused on four main categories: Performance, Accessibility, Best Practices, and SEO. The results demonstrated outstanding scores across all tested pages, with Performance scoring between 99–100, Accessibility at 95–96, and perfect scores (100) in both Best Practices and SEO. These results confirm that the system exhibits a high level of technical quality and aligns with modern web development standards. The findings indicate that the system delivers not only functional capabilities but also speed, reliability, and a highly optimized user experience.
OPTIMALISASI DETEKSI WAJAH DLIB-HOG PADA CITRA INTENSITAS RENDAH DENGAN PREPROCESSING CLAHE
Face decection using Dlib-HOG offers high performance under ideal lighting condition but significantly degrades when applied to low-light images. This study evaluates the effectiveness of Contrast Limited Adaptive Histogram Equalization (CLAHE) as a preprocessing method to enhance face detection accuracy under poor lighting conditions. CLAHE is applied to grayscale images to improve local contrast without introducing excessive artifacts, thereby making facial features more distinguishable for the HOG-based algorithm. Experiments were conducted on a facial image dataset with varied lighting conditions, comparing detection results before and after preprocessing. The results show a notable improvement in detection accuracy from 85.7% to 96.4% and a reduction in false negatives, with only a minimal increase in processing time. These findings confirm that CLAHE is an efficient and lightweight enhancement technique for improving the performance of Dlib-HOG on low-quality images.
PENGEMBANGAN SISTEM OTOMATISASI PENGENDALI ALAT PENDINGIN BERDASARKAN SUHU RUANGAN DENGAN MENGGUNAKAN SENSOR LM35
Indoor temperature and humidity control plays an important role in creating a comfortable and energy-efficient environment, especially in tropical areas such as Denpasar, Bali. Manual use of air conditioners (AC) is often less than optimal because it does not consider the actual environmental conditions as a whole. This study designs an AC control automation system based on the Internet of Things (IoT) concept that can be controlled via a web interface. This system combines several sensors, such as LM35 for temperature, DHT22 for humidity, and PIR for motion detection, and is controlled by an Arduino UNO microcontroller. In addition, data transmission is carried out via the HM-10 Bluetooth module and a web-based monitoring interface built using the Python programming language. The developed system is able to display temperature, humidity, and user presence data in real time, and automatically regulates AC operation based on these environmental conditions. Tests show that the LM35 sensor has an error of 1,42% and the DHT22 sensor is 0.73%, with an effective range of PIR and IR sensors of up to 4 meters. Overall, this system has succeeded in saving AC energy consumption by up to 35.49%. Based on these results, this system is considered feasible to be applied in real environments as an efficient and adaptive temperature control solution.
RANCANG BANGUN SISTEM MONITORING IOT PADA PENGISIAN BATERAI SEALED LEAD ACID BERBASIS APLIKASI MOBILE UNTUK MENCEGAH OVERHEATING DAN OVERCHARGING
Sealed Lead Acid (SLA) batteries are prone to damage caused by overcharging and overheating during the charging process. To address this issue, this study aims to design and develop an Internet of Things (IoT)-based monitoring system integrated with a mobile application to wirelessly monitor the charging of two SLA batteries, as well as prevent overheating and overcharging. The system employs the INA219 sensor to measure voltage and current, and the DS18B20 sensor to measure temperature. Current, temperature, and voltage data are transmitted to Firebase using an ESP32 microcontroller and displayed on an Android application called MySyM, developed with Android Studio. This research successfully realizes a functional, accurate, and effective IoT-based monitoring system to enhance the safety of SLA battery charging. The analysis of test results for the INA219 and DS18B20 sensors shows a Mean Absolute Error (MAE) of 0.24995 V for voltage and 2.1068 °C for temperature on the 12 V battery, as well as 0.1299 V for voltage and 1.3295 °C for temperature on the 6 V battery, demonstrating high measurement accuracy.
ANALISIS TEKNIS DAN KELAYAKAN EKONOMI SISTEM PEMBANGKIT LISTRIK TENAGA PLTB TURBIN TULIP DAN PLTS MENGGUNAKAN SIMULASI HOMER PRO
The horizontal axis wind turbine in the smart microgrid system at DH Building, Faculty of Engineering, Udayana University, is not operating optimally due to blade damage. This study aims to evaluate the replacement of the horizontal wind turbine with a tulip-type wind turbine and to analyze its economic feasibility. Simulation and optimization were carried out using HOMER Pro software, considering the local wind and solar energy potential. The simulation results indicate an annual energy production of 103,205 kWh, with contributions from the PV system at 61.5% and the wind turbine at 38.5%. From an economic perspective, the project yields a Net Present Cost (NPC) of Rp 1,668,925,000, a Levelized Cost of Energy (LCoE) of Rp 4,368.36/kWh, and a Payback Period of 16 years and 8 months. The feasibility analysis results in a Net Present Value (NPV) of –Rp 308,312,810.02 and a Profitability Index (PI) of 0.7635. These findings demonstrate that the project is not financially feasible under the PLN tariff of Rp 1,699.53/kWh and a discount rate of 8.5%.
PERANCANGAN SPBKLU SEPEDA MOTOR LISTRIK DAN PEMILIHAN LOKASI PEMASANGAN DI BALI SELATAN
The limited availability of fossil fuel reserves and the fact that their formation takes millions of years have driven the accelerated adoption of electric vehicles as a strategic step to reduce carbon emissions. Bali, as one of the leading regions in the clean energy transition, requires adequate infrastructure support, particularly charging stations as the main facilities for electric vehicles, whose development must take into account proper location selection and design. This study focuses on the design and location selection of battery swapping stations for electric motorcycles (SPBKLU) in South Bali, including three-dimensional designs and electrical layouts, as well as location determination using the Analytical Hierarchy Process (AHP) method by evaluating potential sites. The results of this study are one optimal location for SPBKLU installation, accompanied by a three-dimensional design suited to the site’s characteristics and the SPBKLU’s electrical layout. In the future, it is expected to serve as a study and reference for the development of electric vehicle infrastructure in Bali, accelerating public adaptation to this technology.
RANCANG BANGUN SISTEM PAYUNG OTOMATIS BERBASIS INTERNET OF THINGS
This study designs an Internet of Things (IoT)-based automatic umbrella system that can be operated manually or automatically via the Blynk application. The process begins with device initialization, including the configuration of the ESP32, servo motor, rain sensor, RTC, push button, and switch. The device then connects to a Wi-Fi network to enable data transmission and reception. In manual mode, the user can open or close the umbrella using a physical button or commands from Blynk. In automatic mode, the system follows a preset schedule: the umbrella opens from 08:00 to 16:00, remains open from 16:00 to 22:00 if rain is detected, and closes from 22:00 to 08:00. Data such as servo position, umbrella status, time, and operation mode are sent to Blynk in real time. Test results indicate that the system functions according to the design, provides ease of use, and helps protect.
RANCANG BANGUN SISTEM SENSOR OTOMATIS PADA ALAT PENERANGAN JALAN (APJ) DI JALAN BUKIT DHARMA RAYA JIMBARAN
Street lighting plays a crucial role in supporting public safety and comfort, especially at night. However, many areas, such as Jalan Bukit Dharma Raya Jimbaran, still lack adequate lighting systems. This study designs and implements an intelligent street lighting system based on the Internet of Things (IoT), utilizing the ESP32 Devkit V1 as the central controller, along with an LDR sensor, ultrasonic sensor, and an AC Light Dimmer to automatically adjust light intensity according to time and traffic conditions. Test results show that the system operates efficiently and adaptively, achieving energy savings of up to 17.6% and cost savings of Rp 54.39 compared to a manual system, with efficiency levels varying depending on road user activity. The prototype has proven effective in enhancing energy efficiency and offers an adaptive lighting solution that can be further developed to support the concept of a sustainable smart city.
EVALUASI KEBERGUNAAN SISTEM INFORMASI ADMINISTRASI COASS MENGGUNAKAN SYSTEM USABILITY SCALE (SUS)
The adoption of new technology in professional settings is often hindered by low user acceptance, making usability a key factor in successful implementation. This study aims to assess the perceived usability of a web-based administrative information system for the Coass program at the Dental and Oral Hospital (RSGM). The evaluation used the System Usability Scale (SUS) method with 41 respondents, including Coass students, dentists, and administrative staff. The average SUS score was 80.121, categorized as "Excellent." These results indicate that the system is highly user-friendly and well-accepted, reflecting effective interface design and user experience as strong indicators of institutional adoption.
RANCANG BANGUN PEMBANGKIT LISTRIK TENAGA MIKRO HIDRO TURBIN CROSS-FLOW PADA SUNGAI AYUNG
The Cross Flow turbine is a type of turbine that utilizes hydraulic energy (water) from the Ayung River flow as its driving force and is very suitable for use in places with low head. Currently, the Cross Flow turbine is still very little used in Indonesia, especially in Bali. This is due to the difficulty of direct measurements by conducting tests related to influential parameters in the field. Therefore, it is necessary to. create a Micro. Hydro Power. Plant (MHP) with adequate terrain and water discharge and is not difficult to measure so as to obtain specific data. This study aims to create a design, determine the turbine specifications, analyze the torque, rotation speed, voltage, current, power, and, efficiency. generated from the MHP prototype with the Cross Flow turbine. The benefits of this study are also, expected. to be a referencei for further researchers to conduct research on MHP. The methods used in this study are, the library method, and the observation method. This study also discusses the analytical study of, the existing. hydropower potential, namely, the. water flow discharge and the height of the waterfall (head) of the Ayung River water flow. The turbine design calculation obtained an effective height of 6 meters with an inlet water velocity of 10.63 m/s and a circumferential velocity of 10.22 m/s indicating that the runner has an outer diameter of 0.15 meters, an inner diameter of 0.1 meters, a runner width of 0.1 meters, a distance between blades of 0.026 meters, a blade width of 0.025 meters, and a total of 18 blades. This prototype, test uses, a water flow, rate of 7 L or 0.007 opening, a guide vane angle of 30. The output produced in the no-load test obtained an average. turbine rotation results before being, coupled to a generator of 539 rpm, an average, turbine rotation results after being coupled of 415 rpm. The average result of the. largest turbine rotation under load is 504 rpm, the largest, generator rotation result under load is 306 rpm, the largest average generator, voltage. result is 9.64 volts, the, largest average. generator, current result, is 0.33 Ampere, thei largest. average, generator, power result is 3.23 Watts, the largest torque result is 0.07 Nm, the largest. PLTMH efficiency result is 6%.
PEMANFAATAN INTERNET OF THINGS (IOT) PADA PERANCANGAN SISTEM BANGUNAN CERDAS
The development of Internet of Things (IoT) technology has made a significant contribution to the design of smart building systems. This research discusses the utilization of IoT in designing smart building systems based on previous studies. The focus of the discussion includes the use of controllers, various types of sensors and control devices, and system scope. By understanding the use of IoT devices and the approaches used in prior research, this study is expected to serve as a reference in the development of smart building systems to be more adaptive and efficient in the future.
RANCANG BANGUN PROTOTYPE MONITORING SYSTEM BERBASIS INTERNET OF THINGS PADA INKUBATOR PENETASAN TELUR AYAM
The hatching process of chicken eggs is highly dependent on a stable incubation environment, especially consistent and standard temperature and humidity. Fluctuations or instability of conditions within the incubator can significantly reduce the success rate of egg hatching (hatching) as well as degrade the quality of the chicks produced. In response to this challenge, this study developed an Internet of Things (IoT)-based monitoring system. The system is designed to monitor crucial parameters such as temperature, humidity, electric current, and voltage inside the incubator. The data collected from the monitoring is then transmitted using the ESP32 module to the ThingSpeak platform. This integration allows users to monitor the condition of the incubator at any time and remotely over an internet connection, providing flexibility and ease of supervision. The test results show that the developed system is able to provide accurate and responsive environmental condition data, and plays an important role in maintaining the stability of the incubation environment. This is expected to increase egg hatchability and support the production of better quality chicks.
RANCANG BANGUN E-HEALTH TRACKER UNTUK DETEKSI DETAK JANTUNG, SATURASI OKSIGEN, SUHU TUBUH, DAN TEKANAN DARAH BERBASIS IoT
The Internet of Things (IoT)-based health monitoring system presents a potential solution to improve remote healthcare services, particularly in areas with limited access. This study developed an IoT-based E-Health Tracker capable of measuring four vital health indicators: heart rate, oxygen saturation (SpO₂), body temperature, and blood pressure. The system integrates the MAX30102, DS18B20, and MPX5050GP sensors with Arduino Uno and ESP32 microcontrollers. Measurement data is displayed locally via an LCD TFT. Evaluation was carried out through experimental testing involving 5 participants over 7 consecutive days (a total of 35 samples). The system’s results were compared with conventional medical devices (oximeter, thermometer, and blood pressure monitor), and accuracy was assessed using the Mean Absolute Percentage Error (MAPE) method. The results showed that the system achieved very good to good accuracy levels, with MAPE values of 1.75% for heart rate, 1.28% for SpO₂, 2.67% for body temperature, and 7.74% for blood pressure. This system can serve as an alternative for IoT-based health monitoring.
RANCANG BANGUN SISTEM MONITORING PERTANIAN HIDROPONIK BERBASIS IoT DAN APLIKASI MOBILE (HYDROTECH)
Urban agricultural land conversion encourages the use of hydroponic systems. However, people's busy lives make it difficult to monitor the nutrition and environment of hydroponic plants. This study developed a monitoring system called Hydrotech, an IoT-based hydroponic monitoring system with an ESP32 microcontroller and pH, TDS, temperature (DS18B20), and water level sensors. Data from the sensors is sent to Firebase and displayed through a mobile application. The method used is an experiment and literature study. Testing was carried out by planting lettuce using the Hydrotech system to evaluate its performance. Primary data was obtained from device testing which includes data from research on the sensors used, while secondary data was obtained from previous research sensor data as a comparison with the current study. The results of this study indicate that the four sensors used, namely the pH, TDS, water level, and temperature DS18B20 sensors, can function properly. Hydrotech is also equipped with an Android application to display sensor data in real time and present historical data for each sensor used for further analysis on hydroponic plants. The Hydrotech application is also filled with a planting calendar as a reminder of planting and harvesting times for hydroponic plants. This Hydrotech monitoring system helps city residents manage hydroponics optimally and efficiently in terms of both energy and time.
STUDI PERBANDINGAN EFISIENSI ENERGI DAN BIAYA OPERASIONAL KOMPOR INDUKSI DAN LPG BERBASIS IOT
This study designs an Internet of Things (IoT)-based monitoring system for 2 kW induction and 2 kW LPG stoves, supporting Indonesia's 2060 Net Zero Emission energy transition policy. Utilizing Arduino Mega 2560 with ESP8266, PZEM-004T sensor, K-type thermocouple, load cell, and Blynk platform, the system provides real-time monitoring of voltage, current, power, temperature, gas mass, and operating time. Data is accessible via a mobile application and stored on an SD card for analysis. Safety features include remote electricity/gas cut-off and active stove notifications. Testing reveals the induction stove's higher efficiency, heating 400 ml of cooking oil in 193 seconds with 0.06 kWh, compared to the LPG stove's 281 seconds with 19.18 grams of gas. Operational cost analysis indicates the induction stove is more economical (Rp 101.97) than subsidized LPG (Rp 159.87), suggesting a more favorable long-term investment for induction technology. By facilitating data collection, remote control, and review, the proposed system allows for evaluation of both technical and economic efficiencies. This study offers an IoT based technical solution and economic assessment that support the national policy shift toward induction stove.
ANALISIS KELAYAKAN INVESTASI PEMBANGKIT LISTRIK TENAGA SURYA PADA ATAP GEDUNG RUMAH SAKIT UNIVERSITAS UDAYANA
The increasing global electricity demand, predominantly met by fossil fuels, necessitates renewable energy development. Indonesia, with its vast solar potential, still faces limited implementation of Solar Power Plants (PLTS). This study analyzes the investment feasibility of a rooftop PLTS at Udayana University Hospital (RSPTN Universitas Udayana), utilizing 2023 electricity consumption data and current component pricing. The research aims to determine the Cost of Energy (COE), conduct a comprehensive economic analysis using Net Present Value (NPV), Internal Rate of Return (IRR), Profitability Index (PI), and Payback Period (PP), and propose a suitable PLTS management model. Findings indicate strong financial viability for this PLTS investment. Calculations reveal a Life Cycle Cost (LCC) of Rp3,190,730,607, a Capital Recovery Factor (CRF) of 0.0746, and an estimated annual energy production of 498,955 kWh. The calculated COE is Rp803.00. The investment yields a positive NPV of Rp3,818,228,293, a PI of 2.357 (>1), and a Payback Period (PP) of 6 years and 9 months, well within the system's operational lifespan. The positive IRR (10.59%) further supports its financial viability, positioning this rooftop PLTS project as a sound and sustainable investment for RSPTN Universitas Udayana.
PENERAPAN METODE AGILE SCRUM DALAM PENGEMBANGAN SISTEM INFORMASI ADMINISTRASI KEGIATAN COASS (CO-ASSISTANT) PADA RUMAH SAKIT PENDIDIKAN GIGI DAN MULUT
The manual administration of the Co-Assistant (Coass) program at Dental and Oral Education Hospitals is often inefficient, prone to delays, and lacks transparency in data handling. To address these limitations, this study implemented a web-based information system developed using the Agile Scrum methodology. Development was carried out through five iterative sprints, totaling 106 story points, enabling the team to incrementally build and refine system features in alignment with stakeholder needs. The Scrum approach not only facilitated the completion of the product backlog but also proved instrumental in managing complex business logic and ensuring seamless inter-module integration. Key outcomes include enhanced efficiency in logbook recording, streamlined clinical assessment workflows, and improved data transparency. These results suggest that Agile Scrum is well-suited for dynamic, semi-academic environments such as teaching hospitals. This research offers a replicable, adaptive development model that can guide other health education institutions in accelerating the digital transformation of their academic and clinical administrative processes.
RANCANG BANGUN SOLAR TRACKER SINGLE AXIS BERBASIS ARDUINO UNO
Indonesia has abundant solar energy potential; however, its utilization remains limited due to dependence on fossil fuels and the low efficiency of solar panels caused by static installation systems. To address this issue, this study designed and developed a prototype of an automatic single-axis solar tracker based on Arduino Uno to optimize solar energy absorption. The system is controlled by the Arduino Uno R3 for automatic adjustment of the solar panel position, and the ESP32 is used for real-time monitoring of environmental and electrical parameters. The sensors employed include the BH1750 for light intensity, DHT22 for temperature and humidity, INA219 for voltage and current, and ACS712 for current. Test results indicate that the system is capable of automatically adjusting the solar panel angle, accurately monitoring environmental parameters, and generating stable electrical power for eight hours. Although some instability in current readings was observed when the system operated on battery power, the prototype has proven effective and feasible for further development to enhance the utilization of solar energy.
PENGEMBANGAN APLIKASI WEB UNTUK MONITORING REKAM MEDIS PADA SISTEM E-HEALTH TRACKER BERBASIS IOT
The digital transformation in the healthcare sector continues to advance significantly, particularly in the recording and management of electronic medical records. This study proposes the development of a web-based application for monitoring medical records within an E-Health Tracker system that leverages the Internet of Things (IoT), designed using a User-Centered Design (UCD) approach. The system aims to provide seamless access to health information for users through an intuitive interface and cross-device compatibility. The integration of IoT devices enables the transmission of vital health indicators—such as heart rate, body temperature, and oxygen levels—to a central server, which are then visualized through a web-based platform. A key advantage of this application lies in its flexible access and its potential to bridge gaps in healthcare services, especially in regions with limited medical infrastructure. This research is expected to contribute meaningfully to the equitable distribution of healthcare access and to raise public awareness of health literacy through the implementation of IoT-integrated web technologies.
RANCANG BANGUN PERBANDINGAN LUAS BATERAI BERBAHAN ALUMINIUM MENGGUNAKAN ELEKTROLIT AIR LAUT BERSIRKULASI TERBUKA DENGAN SISTEM KONTROL DATA TERSIMPAN
The utilization of renewable energy in Indonesia remains suboptimal, despite its substantial potential. One promising approach to harness this potential is through aluminum-air batteries using seawater as an electrolyte, offering greater safety and sustainability compared to conventional batteries. However, the performance of aluminum-air batteries can still be improved, particularly in terms of stabilizing the no-load voltage. This study aims to determine the voltage output generated by two battery design methods with identical electrode surface areas: one configuration using four cells measuring 5 × 5 × 0.2 cm arranged in series, and the other using a single cell measuring 10 × 10 × 0.2 cm. Both designs operate with an open circulation system. For testing, both battery configurations were monitored using an Arduino microcontroller as a voltage reader, which captured the voltage output from each battery. The voltage output from the aluminum-air batteries was read by the Arduino through the ADC pin and displayed in real time on a 16x2 I2C LCD screen, with the seawater circulation driven by a DC pump acting as the flow medium. The experimental results showed that the aluminum-air battery with four cells of 5 × 5 × 0.2 cm arranged in series achieved a maximum voltage increase of 255.7%, reaching 4.34 V, compared to the single-cell configuration of 10 × 10 × 0.2 cm, which produced only 1.22 V.