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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
 18   19   20   21   22 
Rancang Bangun Palang Pintu Otomatis Pada Perumahan Penduduk Menggunakan Image Processing Dengan Metode Optical Character Recognition (OCR) Berbasis Arduino Uno Jeffri Irjaya Nawawi; Priyo Sasmoko
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.v22i2.90247

Abstract

Automatic gate barriers in residential areas—primarily within housing complexes—serve to regulate and monitor access, as well as help prevent criminal acts targeting residents’ motor vehicles. Gate barriers in residential areas generally rely on makeshift equipment and infrastructure, making it highly feasible to improve them with the prototype developed by the author. Utilizing an HC-SR04 ultrasonic sensor, a servo motor, and image recognition methods, this device is used to automatically detect registered license plates to open and close the gate. It can be operated either automatically or manually, depending on the needs of the residents.
Implementasi Load Cell Sebagai Umpan Balik Sistem Kendali Gaya Tekan Pada Rancang Bangun Alat Pres Modul LED AC Di Vocalite Ryan Juliary; Dista Yoel Tadeus
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.v23i1.90337

Abstract

The process of installing AC LED modules into the housing in Vocalite requires sufficient pressure to lock the modules in place; however, excessive force can damage the plastic housing or electronic components. This study designed an Arduino Nano-based pneumatic press equipped with a load cell as the primary feedback for pressure. Load cell data is read via the HX711, while the WPT-83G pressure sensor is used to monitor air pressure. The Arduino Nano controls a relay and a 5/2-way solenoid valve to actuate the AirTAC SC 50 x 150 cylinder and halt the process when the force reaches the setpoint. Testing included power supply output verification, load cell calibration, pressure readings, characterization of the relationship between pressure and thrust force, and repeated testing on the AC LED modules. Test results showed an average load cell error of 0.26% and an average pressure sensor error of 0.52%. The actual thrust increased from 151.54 N at 1 bar to 380.09 N at 5 bar, while the theoretical calculation increased from 196.35 N to 981.75 N. In repeated testing with a target of 303.08 N, the system successfully deactivated the relay and retracted the cylinder in 20 out of 20 cycles. All samples had an installation depth of 5 mm with a range of 0 mm, and no visual damage was found. However, some of the force characterization data exceeded the load cell’s nominal capacity of 20 kg; therefore, validation using a higher-capacity force sensor is necessary for a more robust quantitative force analysis 
Implementasi Sensor PZEM-004T Sebagai Alat Penghitung Biaya Listrik Pada Pelanggan Pascabayar Tegangan Rendah 1 Fasa Yang Dilengkapi Sistem Monitoring Arus Berlebih Berbasis Telegram Rizki Ardianto; Eko Ariyanto
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.v22i1.90228

Abstract

In 2022, approximately 41.47% of residential electricity customers in Lampung Province were still using postpaid kWh meters. However, many residents have complained that their electricity bills are inaccurate. Excessive current in residential electrical systems can cause the MCB to trip, disrupting electricity usage. If left unchecked, this can lead to new problems such as electrical short circuits, which can trigger fires. The PZEM-004T sensor was implemented as a monitoring tool to track the amount of electricity consumed, along with an estimate of the electricity bill, and utilizes the Telegram platform to monitor excessive current in residential electrical installations. The device is designed for single-phase, low-voltage residential applications with a capacity of 450 VA to 900 VA. Measurement and testing results showed an average error percentage of 2.67% for current, 0.3995% for voltage, 1.78% for power, 1.84% for electrical energy consumption, and 1.5% for the estimated electricity bill. These values remain within the permissible limits set by Ministry of Energy and Mineral Resources Regulation No. 4 of 2009, which specifies a tolerance of ±2%.
Rancang Bangun Mesin Coil Winding Otomatis Berbasis Mikrokontroler Arduino Nano dan Motor Stepper Nema17 Untuk Coil Skala Kecil Uwaeis Bima Pangestu; Fakhruddin Mangkusasmito
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.v22i4.90303

Abstract

The coil-winding process is still largely performed manually, particularly in small-scale industries, assembly workshops, and educational laboratories, resulting in several drawbacks such as reliance on operator skill, relatively long production times, and inconsistent winding quality. This study aims to design and build an automatic coil-winding machine based on an Arduino Nano with a NEMA 17 stepper motor drive. The developed system uses two stepper motors—one to rotate the spool and the other to guide the wire—with the number of windings and wire diameter controlled via input buttons connected to an LCD as the user interface, as well as a limit switch to restrict the movement of the wire-guiding mechanism. Testing was conducted using 0.15 mm diameter enameled wire of Brand A, 0.15 mm of Brand B, and 0.30 mm wire. System performance was evaluated by measuring coil resistance, analyzing the winding distribution at four measurement points (P1, P2, P3, and P4), and performing statistical analysis using mean, standard deviation, and coefficient of variation. The test results showed that all measurement points had relatively small standard deviations, indicating that the resulting winding distribution was uniform, while the accuracy calculations showed values above 98% for all wire variations tested. Based on these results, the developed automatic coil winder is capable of performing the winding process automatically
Rancang Bangun Weather Station Berbasis Mikrokontroler Dengan Pembangkit Listrik Tenaga Surya Dan Transmisi Data Menggunakan Lora Rizal Krisna Saputra; 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.v22i3.90291

Abstract

Climate change demands the development of energy-efficient and autonomous weather monitoring systems capable of operating in remote areas. This study designs and implements a weather station based on the ESP32 microcontroller, powered by a standalone solar power system (PLTS), and utilizing LoRa for long-range wireless data transmission. The system integrates several sensors to measure temperature and atmospheric pressure (BMP280), wind speed and direction (anemometer and RS232-TTL wind vane), and rainfall (tipping bucket rain gauge). Sensor data is transmitted periodically to a receiver node, displayed in real time via a Node-RED dashboard, and automatically logged in daily CSV format. The system also includes LED indicators to show operational status. Testing results demonstrate that the system can operate stably for 24 hours without access to electricity or internet, achieving over 90% data transmission success rate with a communication range of up to 2 km. The solar power system reliably meets the energy requirements of the station. These findings indicate that the developed weather station is effective and suitable for deployment as an independent weather monitoring solution, particularly in remote areas lacking conventional communication infrastructure.
Simulasi Manuver Pada Jaringan Tegangan Menengah Penyulang Tanjung Jati B 03 PT PLN (Persero) Berbasis Arduino Mega 2560 Dengan Monitoring VT SCADA 12.1 Aulia Nurul Yunizah; Fakhruddin Mangkusasmito
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.v21i3.90271

Abstract

A protection system is necessary in a distribution network to ensure the network remains reliable. The purpose of protection equipment in a distribution network is to minimize damage to the system. In addition, protective equipment is also useful for minimizing the spread of faults so that outages can be limited to smaller areas. Given these functions, network maneuvers are necessary, utilizing protective equipment to prevent faults from spreading further. To facilitate learning about network maneuvers, a maneuver simulation tool was developed for this final project. The results of experiments conducted on this simulation tool showed that the PMT was set to a current of 0.5 A, the recloser was set to a current of 0.5 A, and the LBS was set to a current of 0.4 A.
Rancang Bangun Thermal Energy Storage Sebagai Penyimpanan Energi Berbasis Solar Panel Gilar Wirayudha; 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.v23i2.90343

Abstract

The intermittent nature of solar energy causes photovoltaic power output to fluctuate with solar irradiance, requiring an energy storage system to maintain energy availability when panel output decreases. This study designs, constructs, and evaluates a silica-sand-based Thermal Energy Storage prototype powered directly by photovoltaic panels. The prototype uses 57 kg of silica sand with a particle size of 30–50 mesh as a sensible heat storage medium. The final configuration employs two 545 Wp photovoltaic panels connected in series, two series-connected resistive heaters rated at 42 V and 500 W each, two K-type thermocouples, and rockwool-aluminum foil insulation. An ESP32 and Arduino Nano monitoring system records sand temperature, voltage, current, power, and estimated solar irradiance to a spreadsheet. Three configurations were evaluated. The highest temperature increased from 103.63°C in the first configuration to 195.13°C in the second and 230.13°C in the third. Complete insulation enabled the system to retain an average temperature of 100.09°C after approximately 16 h of cooling, with an average cooling rate of 5.84°C/h. For the analyzed charging period, 4,099 Wh of electrical energy produced 1,703.49 Wh of stored thermal energy, corresponding to a thermal storage efficiency of 41.56%. The results show that increasing the number of panels and heaters, combined with comprehensive insulation, improves heating and heat-retention performance.

Page 22 of 22 | Total Record : 217

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