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INDONESIA
GEMA TEKNOLOGI
Published by Universitas Diponegoro
ISSN : 08520232     EISSN : 2656582X     DOI : -
Core Subject : Science,
Computer Science & IT
Gema Teknologi Journal (pISSN : 0852-0232, eISSN : 2656-582X) is an open access journal published by Vocational School, Diponegoro University, Indonesia. Gema Teknologi publishes articles from various engineering disciplines (the results of original scientific research or new scientific studies of literature). Editor receives articles both in English and Indonesian. Gema Teknologi Journal is published 2 (two) times a year, on April and October.
Arjuna Subject : -
Articles 217 Documents
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Pengaturan Suhu Dan Kelembaban Serta Penyiraman Pestisida Secara Otomatis Untuk Peningkatan Produksi Jamur Tiram Yonathan Dwi Nugroho; Iwan Setiawan; Yuniarto Yuniarto
Gema Teknologi Vol 21, No 4 (2022): October 2021 - April 2022
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i4.90288

Abstract

Oyster mushroom production is often hindered by suboptimal temperature and humidity, as well as manual pest control, leading to inefficiency. This project proposes a prototype system for automatic temperature and humidity control, along with scheduled pesticide spraying, to improve the efficiency and productivity. This system uses an ESP-32 microcontroller, a DHT22 sensor for temperature and humidity monitoring, and an RTC DS1307 for scheduling. Actuators include heaters, Peltier coolers, exhaust fans, humidifiers, and a pesticide pump. Users can monitor and configure the system locally via a 16x2 LCD and keypad or remotely through a web dashboard. Calibration of the DHT22 sensor reduced temperature reading errors from 4.32% to 0.31% and humidity errors from 1.4% to 0.22%. The system maintained temperature within 26–28°C (setpoint 27°C, differential 2) and humidity within 88.5–91.5% (setpoint 90%, differential 3). The automated pesticide spraying functioned according to schedule (every 3 days for a duration of 5 seconds at 17:00). The web dashboard interface showed good performance with a Google Lighthouse score of 100 and a speed index of 0.9 seconds. Oyster mushrooms grow optimally at approximately 4 cm per day and are ready for harvest by the fourth day.
Rancang Bangun Sistem Monitoring Dan Pemutusan Otomatis Sambungan Sementara (Pesta) Berbasis IoT (Internet Of Things) Latiefa Achsani Yusfira Sulaiman; Eko Ariyanto
Gema Teknologi Vol 21, No 3 (2021): April 2021 - October 2021
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i3.90249

Abstract

Temporary Connection (PESTA) is an electricity connection service provided by PT. PLN (Persero) intended for customers’ temporary needs or those requiring service for a specific period, with a capacity greater than the installed contracted capacity. Examples of temporary customer needs include electricity for repair shops, celebrations, etc. Limited field personnel, combined with overlapping tasks related to PBPD (New Connections and Capacity Changes), the lack of direct notification regarding the completion time of temporary connections, and the distance to customers’ homes, result in delays in normalizing temporary connections. Delays in normalizing temporary connections affect customers’ metered usage, which does not match the initial contracted capacity, resulting in losses for PT.PLN (Persero) because the metered usage is billed at the initial contracted rate rather than the temporary connection rate (non-technical loss). To address these issues and minimize losses, a monitoring and automatic disconnection device for temporary connections was developed to prevent delays in normalization and achieve energy savings (saved kWh). This device utilizes an Automatic Transfer Switch (ATS) system with a relay and timer that automatically transfers the load from the PESTA kWh meter to the customer’s kWh meter. The ESP-32 module acts as a microcontroller that processes data from the PZEM-004T sensor (with an error margin of 0.02–0.05%) and sends automatic disconnection notifications via the Blynk app and SMS.
Rancang Bangun Pembangkit Listrik Tenaga Bayu Menggunakan Turbin Tipe Savonius 6 Sudu Dengan Generator AC Berbasis Arduino MEGA 2560 Julio Abiyu Putra; Fakhruddin Mangkusasmito
Gema Teknologi Vol 23, No 2 (2025): October 2024 - April 2025
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v23i2.90339

Abstract

The design and construction of a prototype for a Wind Power Plant (PLTB) using a three-blade Archimedes wind turbine has been completed. This turbine utilizes a DC motor that has been converted into a DC generator, with overall dimensions of 120 x 80 x 80 cm, powered by wind energy. Testing was conducted to evaluate the efficiency of converting wind energy into electrical energy based on various wind speeds and types of loads, including resistors, DC motors, and LED lamps. Test results indicate that system efficiency varies depending on wind speed and load characteristics. The highest efficiency was achieved at an optimal wind speed, ranging from 60-80%, with a power coefficient between 0.1033 and 0.1699. For a 15-watt LED lamp load, the average voltage recorded was 7.404 V, whereas, for a 5-watt DC motor load, the average voltage reached 10.132 V. The testing also revealed that the highest power value for resistor loads was obtained with a 10.5 Ω resistor, delivering 2.22 W. This study highlights the importance of optimizing turbine and generator system design to enhance energy conversion efficiency under varying wind speed conditions.
Perbandingan Efisiensi Daya Pada Solar Charge Controller Menggunakan Maximum Power Point Tracking (MPPT) dengan Metode Algoritma Adaptive Neuro-Fuzzy Interence System (ANFIS) dan Incremental Conductance Berbasis IoT Hafizh Prasetio Utomo; Arkhan Subari
Gema Teknologi Vol 22, No 1 (2022): April 2022 - Oktober 2022
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v22i1.90240

Abstract

Solar panels are a type of renewable energy technology that can convert energy from sunlight into electrical energy. Solar panels consist of an array of solar cells arranged in such a way as to effectively absorb sunlight. Solar panels provide a readily available and free source of renewable energy; however, their efficiency remains relatively low. MPPT (Maximum Power Point Tracking) solar charge controllers are designed to maximize the power output from solar panels and regulate battery conditions to prevent overcharging. This study aims to compare the Adaptive Neuro-Fuzzy Inference System (ANFIS) method and the Incremental Control method using a boost converter to achieve maximum output in terms of voltage, current, and power using an MPPT module. Simulations were conducted using both sunlight and artificial light. Additionally, this MPPT system is integrated with IoT control using an ESP32 microcontroller for remote control.
Rancang Bangun Sistem Manajemen Air Berbasis IoT Dengan Kontrol Fuzzy Logic Pada Hidroponik Raihan Ananto Putra; Dista Yoel Tadeus
Gema Teknologi Vol 22, No 4 (2024): October 2023 - April 2024
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v22i4.90305

Abstract

This study discusses the design and development of an Internet of Things (IoT)-based water management system using Fuzzy Logic Control for backyard hydroponics. The system is designed to monitor and regulate the main parameters, namely nutrient solution pH, water flow rate, and water temperature, in order to maintain optimal plant growth conditions. A pH sensor, a water flow sensor, and a DS18B20 water temperature sensor are used as system inputs, while the ESP32 acts as the main controller that processes sensor data and executes fuzzy logic rules to determine control actions for the actuators. Water temperature control is implemented using a Peltier module combined with a waterblock as the heat transfer medium, while the BTS7960 driver is used to reverse the current direction through the Peltier module. By reversing the current direction, the hot side and cold side of the Peltier module can be interchanged, allowing the system to operate as both a water cooler and a water heater according to the required conditions. Sensor readings are displayed on the LCD, transmitted to the Blynk platform for real-time remote monitoring, and recorded using Google Form as a data logger. The test results indicate that the system is capable of monitoring water parameters in an integrated manner and providing control responses to changes in water flow rate and temperature according to the defined setpoints. Therefore, this system is expected to serve as a practical, adaptive, and efficient solution for automated backyard hydroponic water management
Rancang Bangun Automatic Valve Control Pada Penyimpanan Gas Rawa Berbasis ESP32 Zahratun Diniyah; Priyo Sasmoko
Gema Teknologi Vol 22, No 3 (2023): April 2023 - October 2023
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v22i3.90295

Abstract

This study designs an automatic control system for biogenic shallow gas filling using a PLC based on ESP32, with monitoring via a Telegram Bot. A pressure transmitter sensor measures pressure in real-time, and hysteresis logic controls the compressor operation within a range of 1–3 bar. Pressure values are displayed on the Serial Monitor and sent to Telegram. Test results show that the system operates stably and accurately, with sensor deviation less than ±0.1 bar. The average filling rate is 0.123 bar per minute, and the compressor temperature remains within safe limits. The Telegram Bot responds quickly and provides data that accurately reflects the device’s condition. This system is effective for automatic filling and remote monitoring.
Rancang Bangun Automatic Oil Skimmer Dengan Metode UV Visible Transmission Spectroscopy Berbasis ESP32 Pada Limbah Industri Hanif Abdul Qodir; Arkhan Subari
Gema Teknologi Vol 21, No 4 (2022): October 2021 - April 2022
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v21i4.90284

Abstract

Electricity is a form of energy that has now become a part of life for all mankind. Almost everything that humans use requires electricity to function, where the greater the energy required, the more electrical energy that needs to be generated. The majority of generators used are steam power plants that require coal. Where the coal used requires a mining process which will produce waste, one of which is used oil from coal transport equipment which is undergoing maintenance. This used oil will later mix with water when the workshop is cleaned. To ensure the cleanliness and safety of waste water that will be channeled back into nature, preventive measures need to be taken in the form of using an oil skimmer. Oil skimmers are still rarely used in Indonesia, and still require operator intervention. One method to reduce operator intervention is to automate the oil skimmer tool by utilizing the UV Visible Transmission Spectroscopy method, ESP32, and a belt skimmer made from polypropylene. From this method it can be seen that oil causes changes in light intensity, where these changes indicate the amount of oil in the water.
Rancang Bangun Monitoring Motor Induksi Tiga Fasa Berbasis IoT (Internet Of Things) Farah Salsabila Habib; Fakhruddin Mangkusasmito
Gema Teknologi Vol 23, No 2 (2025): October 2024 - April 2025
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v23i2.90345

Abstract

Three-phase induction motors are widely used as the primary drive in the industrial sector because of their high reliability in supporting production processes. This final-year research project developed an IoT-based monitoring system for three-phase induction motors to monitor voltage, current, power, and temperature in real time via a website, using PZEM-004T (voltage, current, power) and DS18B20 (temperature) sensors. Motor condition analysis was performed using a diagnostic approach based on the National Electrical Manufacturers Association (NEMA) MG-1 14.36 standard, by calculating the percentage of unbalanced voltage, unbalanced current, and motor load percentage. Testing was conducted on two motor conditions: a loaded Direct-on-Line (DOL) motor with specifications of 2,200 watts (3 HP) and an unloaded star-connected motor with specifications of 0.5 HP. Test results for the DOL motor showed a current sensor accuracy of 98.79% (error 1.21%), a voltage sensor accuracy of 99.38% (error 0.63%), and a power sensor accuracy of 98.87% (error 1.13%), with unbalanced voltage at 1.23% and unbalanced current at 2.99%, both of which indicate that the motor is in good condition. For the star-connected motor under no-load conditions, the IoT system recorded an unbalanced voltage of 2.37% (risky condition) and an unbalanced current of 8.79% (good condition), which are consistent with manual measurements taken using a digital multimeter and a digital clamp meter (unbalanced voltage of 2.04% and unbalanced current of 9.09%).
Rancang Bangun Sistem Pengendalian Suhu Pada Kandang Ayam Anak Menggunakan Mikrokontroler Arduino Nano Berbasis PID Muhammad Syauqillah; Yuniarto Yuniarto
Gema Teknologi Vol 22, No 2 (2023): October 2022 - April 2023
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v22i2.90245

Abstract

Broiler chicken farming requires a stable environmental condition, particularly in terms of temperature and humidity, to support optimal growth and prevent thermal stress. To overcome the limitations of manual temperature regulation, an automatic temperature control system was designed based on the Proportional Integral Derivative (PID) algorithm using an Arduino Nano microcontroller. This system utilizes the DHT22 sensor to read temperature and humidity, while a keypad allows users to input the desired temperature set point. The PID output signal is used to regulate the power of a PTC heater through an AC Light Dimmer module using Pulse Width Modulation (PWM). Additionally, two fans serve as a ventilation system: an exhaust fan to expel hot air and a cooling fan to introduce fresh air. Testing demonstrated that the system could maintain the cage temperature close to the set point of 34°C with a relative sensor error of only 0.86%. Four rounds of PID tuning were conducted, resulting in optimal parameters of Kp = 21.8, Ki = 0.048, and Kd = 3800. These results show that the system offers more stable and efficient temperature control compared to conventional on-off methods. Furthermore, the system is designed to operate offline without an internet connection, making it suitable for implementation in remote farming areas.
Rancang Bangun Dc-Dc Boost Converter Dual Mode Berbasis Arduino Nano Untuk Kebutuhan Pembelajaran Naren Dramardhani Sasda; Fakhruddin Mangkusasmito
Gema Teknologi Vol 23, No 1 (2024): April 2024 - October 2024
Publisher : Vocational School Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/gt.v23i1.90334

Abstract

 A comprehensive understanding of the operational characteristics of DC-DC boost converters and the fundamental differences between open-loop and closed-loop control systems are crucial learning outcomes in the power electronics curriculum. However, limited laboratory equipment often makes it difficult for students to observe physical phenomena such as voltage drop due to load regulation. This research aims to design and implement a Dual-Mode DC-DC Boost Converter learning module based on an Arduino Nano microcontroller that is compact, accurate, and integrated into a portable suitcase chassis. The power circuit is built using logic-level IRLZ44N MOSFETs, SR3150 Schottky diodes (150 V/3 A), a 330 μH toroidal inductor, and a 47 μF/160 V filter capacitor, operating at a PWM switching frequency of 62.5 kHz. The control circuit is self-powered by a 5 V DC cell phone charger via the Arduino Nano’s USB port. The system incorporates an SPDT toggle switch for instant mode switching between manual open-loop operation and automatic closed-loop PID operation (K_p = 0.2; K_i = 0.4; K_d = 0.0) to lock the target output voltage (12 V–50 V DC) from a variable power supply input (3 V–24 V DC). Experimental testing was conducted under four load conditions (no load, 220 kΩ, 22 kΩ, and 1 kΩ) with transient data recorded at 10 ms intervals, totaling 1,500 samples. The test results show that the voltage divider feedback circuit (K=101) has a high level of accuracy with an average error percentage of 0.88%. Evaluation of the transient response yielded a Mean Square Error (MSE) value of 33.82 under no-load conditions; 35.95 at a 220 kΩ load; 36.10 at a 22 kΩ load; and 46.80 at the heaviest load of 1 kΩ. The PID controller proved highly reliable in compensating for current draw up to 55.0 mA without experiencing steady-state error, making this module highly suitable for use as an interactive laboratory exercise.

Page 19 of 22 | Total Record : 217

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