• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.18 no.6
• /
• pp.133-137
• /
• 2018

Arduino is a small microcomputer that is used in a variety of industry fields and especially is widely used as an open source hardware IoT device. The multi-tasking method of Arduino is divided into super loop timing and RTOS thread method. The super loop timing method is simple and easy to understand. However, when one task is long, it affects the execution of the next task. In addition, RTOS threading has the advantage of being able to run without being influenced by other work time. However, Arduino, a small microcomputer, has a disadvantage in that, when the number of threads increases, the context switching time of the thread causes additional time not included in the super loop timing method have. In this paper, we use Arduino Uno R3 and FreeRTOS to analyze these different features, and the task for the experiment is to send 8000 digital signals to the built-in LED port. If two tasks of the same size are executed, the super loop method executes 3 ms faster than FreeRTOS multitasking. If multiple tasks are executed simultaneously, superloop type task is sequential execution and difference in execution time between first task and last task is large. FreeRTOS method can be executed concurrently, but execution time delay of about 30 ms occurs in context switching time.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2012.11a
• /
• pp.57-59
• /
• 2012

본 논문에서는 소형 임베디드 시스템을 응용하여 원격으로 가정의 에너지를 효율적으로 절약할 수 있는 시스템을 제안한다. 이를 위하여 OpenWrt기반 소형 유무선 공유기를 임베디드 시스템 개발 플랫폼으로 활용하여, DC 모터가 장착된 창문 블라인드를 날씨 변화에 따라 원격지에서 스마트폰으로 제어가 가능하게 하였다. 프로토타입 시스템 구현은 Buffalo사의 WZR-HP-G450H 유무선공유기, Arduino 사의 UNO 인터페이스 보드, DC 모터로 구성하였다. 원격제어 시스템은 iOS 기반으로 애플리케이션을 제작하였다. 전체 시스템의 동작 검증은 스마트폰과 유무선 공유기, 인터페이스 보드의 소켓통신을 통하여 DC 모터의 속도를 원격으로 조절함으로 동작을 확인하였다.

• Journal of information and communication convergence engineering
• /
• v.19 no.3
• /
• pp.161-165
• /
• 2021

Since the first commercialization of beacon-based services in 2011, various services have been provided to improve Bluetooth performance, and research has been conducted to accurately recognize user locations using beacons. The various measurement methods of indoor positioning systems (IPS) include methods using receiver signal strength indicator (RSSI) the strength of which varies greatly in accuracy depending on whether there are obstacles such as cement walls or doors. In this paper, we present a method to provide accurate positioning services even in the presence of obstacles in indoor spaces. To this end, we connect the HM-10 module supporting the beacon with Arduino Uno, to place beacons in three directions in real-world indoor space, and derive an optimal trilateration equation. Based on the derivation, we select the optimal expression for calculating the distance between the beacon and the moving station and use it to verify the coordinate determination for the moving station.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.18 no.3
• /
• pp.1-7
• /
• 2022

In this study, inaccurate RSSI values of beacons are corrected using extended Kalman filter. For the experiment, the beacon was manufactured using Arduino Uno board and HM-10 Bluetooth module. RSSI values according to the distance between beacon and the viewer were measured at intervals of 1m, 1.5m, 2m, 2.5m, 3m, 3.5m, 4m, 4.5m, and 5m. To remove the irregular signal pattern of the beacon, the extended Kalman filter was applied to obtain the average and standard deviation of the actual distance and the measured distance, and it was confirmed that more than 76.6% of the irregular signal pattern was removed after using the extended Kalman filter.In addition, through the smartphone app, it was confirmed that the distance accuracy between the beacon and the measurer was less than the actual distance and the measured distance within 2m, and the standard deviation was small.

• Journal of Information Technology Applications and Management
• /
• v.26 no.5
• /
• pp.41-56
• /
• 2019

Recently great loss of life and property is occurring because of fire, natural disaster, earth quake, tsunami and so on. People spend 80~90% of their time indoor environment like office, supermarket, campus. Therefore Indoor navigation and guidelines system became so essential for most of all. Incase of emergency we must be careful earlier, in such a cases 5G kind of new technology may also cannot work. So immediate action and quick routing notification for guidelines and protection is the most. Considering this issue We proposed indoor evacuating guidance system based on microcontroller Wi-Fi board for Indoor APP using mobile. Focusing various kind of technology like, ok google, voice search APP we purposed node architecture based system. When we listen fire alarm while living inside the room. Then to be safe we connect with server and start Arduino UNO+IoT ESP8266 Wi-Fi shield version1-IoT module to store data in MySQL DB server. We make application to escape out from the building up-to the three exits giving information from source point to destination. Our program can send information to the users emergency location and situations. For this when the user get sound or vibration in their mobile device it indicate fire out near by. At that time we update message from Arduino to DB server for the fixed current position inside the building which give routing signal for that fire out location by changing values from 0 to 1. We have user in point 10 where user is near by. Later we detect Wi-Fi signal form Nodemcu as room of each floor and try to connect with user. Main purpose of this paper is to save life of people in short time and find out the shortest path up to nearest exits in the time of emergencies and rescue them.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.23 no.12
• /
• pp.1687-1692
• /
• 2019

In the era of the fourth industrial revolution, advanced technologies such as the Internet of Things(IoT) and big data are emerging. However, the level of application of IoT to indoor environment is very weak. Therefore, it is necessary to develop a system for analyzing air pollutants or indoor air quality through real-time monitoring using the IoT. This paper implements a system that measures indoor environmental values using Arduino and various sensors, and stores the information obtained from various sensors into a database of server. The information stored in the server was built as a database and utilized in the ventilation system or air cleaner installed in the home or company's room. In the proposed system, it is possible to check the immediate indoor environmental condition through the LED status display of the monitoring sensor module while reducing the cost of the sensor used to implement IoT technology.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.10
• /
• pp.1325-1330
• /
• 2020

New-born babies who require special attention medically are admitted often to incubator. Incubators are well equipped to fulfill take care of infants, but they have to hospital and so expensive. This paper proposes a smart incubator that can solve the problem of convenience and cost aspect of these incubators. Developed incubator enables near-field monitoring using Arduino Uno as the main control device and Bluetooth communication. The environment in the incubator measures temperature and humidity using a DHT22 sensor and the sound using a P5510 microphone. If the temperature and humidity data set by the user are lower or higher than the reference value, it is designed to operate the heating pad using the controller or turn on the fan to allow air circulation. The measured values in the incubator are displayed in real time on the user's smartphone monitoring screen and are programmed using app inventor. Developed incubators can help take care of infants at low cost in the home.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.16 no.5
• /
• pp.256-264
• /
• 2023

Smart farm technology using IoT is one of the technologies that can increase productivity and improve the quality of agricultural products in agriculture, which is facing difficulties due to the decline in rural population, lack of rural manpower due to aging, and increase in diseases and pests due to climate change. . Smart farms using existing IoT simply monitor farms, implement smart plant growers, and have automatic greenhouse opening and closing systems. This paper implements a smart farm system based on MQTT, an industry standard protocol for the Internet of Things, and Node-RED, a representative development middleware for the Internet of Things. First, data is extracted from Arduino sensors, and data is collected and transmitted from IoT devices using the MQTT protocol. Then, Node-RED is used to process MQTT messages and store the sensing data in real time in MongoDB, a representative NoSQL, to store the data. Through this smart farm system, farm managers can use a computer or mobile phone to check sensing information on the smart farm in real time, anytime, anywhere, without restrictions on time and space.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.5
• /
• pp.933-940
• /
• 2017

This thesis shows the emotional light that stabilizes various human heart rates through the three elements of LED. This experiments confirm the change of heart rates when subjects see the static LED, fluid LED That was controlled by the guitar chord and beat in a given music and without light Consequently, the experiment proved that the bpm slope of test subject during specific time in liquid LED, -12.85, was steeper than -12.05 in static LED and -11.05 without light, which showed that fluid LED is more effective to stabilize heart rate than other conditions.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.13 no.6
• /
• pp.1275-1280
• /
• 2018

We made a smartphone interlocking location tracking streetlight and remote display device to compensate the defect of real time identifiable CCTV streetlights and child safety notification applications. It controls brightness of LED by detecting the surrounding brightness and objects with ultrasonic sensor and illuminance senor. The CCTV receives the location of smartphone by Bluetooth and takes the target of the location. It realizes a wireless transmission system that the video is upload to the tablet PC via WiFi.