• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11a
• /
• pp.937-939
• /
• 2005

본 논문에서는 임베디드 프로세서인 ATmega128과 W3100A 이더넷 칩을 이용하여 범용 웹 모니터링 시스템을 구현하였다. 카메라를 이용한 동영상 오디오, RS-422 통신, 디지털/아날로그 신호의 입출력 등 다양한 제어 모니터링 정보를 통합하여 범용으로 사용할 수 있고, 소형, 저가, 저전력 소모가 가능하도록 설계, 구현하였다. 클라이언트 프로그램은 Java Applet으로 개발 하여 별도의 소프트웨어 설치 없이 웹브라우저를 통하여 접속되고, 원격지의 영상 및 각종 기기들의 상태를 실시간으로 모니터링하여 GUI기반의 각종 메뉴를 사용하여 원격 시스템을 편리하게 제어 할 수 있다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1826-1829
• /
• 2005

Recent advancement in wireless communications and electronics has enabled the development of low power sensor network. Wireless sensor network are often used in remote monitoring control applications, health care, security and environmental monitoring. Wireless sensor networks are an emerging technology consisting of small, low-power, and low-cost devices that integrate limited computation, sensing, and radio communication capabilities. Sensor network platform for health care has been designed, fabricated and tested. This system consists of an embedded micro-controller, Radio Frequency (RF) transceiver, power management, I/O expansion, and serial communication (RS-232). The hardware platform uses Atmel ATmega128L 8-bit ultra low power RISC processor with 128KB flash memory as the program memory and 4KB SRAM as the data memory. The radio transceiver (Chipcon CC1000) operates in the ISM band at 433MHz or 916MHz with a maximum data rate of 76.8kbps. Also, the indoor radio range is approximately 20-30m. When many sensors have to communicate with the controller, standard communication interfaces such as Serial Peripheral Interface (SPI) or Integrated Circuit ($I^{2}C$) allow sharing a single communication bus. With its low power, the smallest and low cost design, the wireless sensor network system and wireless sensing electronics to collect health-related information of human vitality and main physiological parameters (ECG, Temperature, Perspiration, Blood Pressure and some more vitality parameters, etc.)

• ETRI Journal
• /
• v.29 no.3
• /
• pp.259-269
• /
• 2007

The ubiquitous flexible operating system (UbiFOS) is a real-time operating system designed for cost-conscious, low-power, small to medium-sized embedded systems such as cellular phones, MP3 players, and wearable computers. It offers efficient real-time operating system services like multi-task scheduling, memory management, inter-task communication and synchronization, and timers while keeping the kernel size to just a few to tens of kilobytes. For flexibility, UbiFOS uses various task scheduling policies such as cyclic time-slice (round-robin), priority-based preemption with round-robin, priority-based preemptive, and bitmap. When there are less than 64 tasks, bitmap scheduling is the best policy. The scheduling overhead is under 9 ${\mu}s$ on the ARM926EJ processor. UbiFOS also provides the flexibility for user to select from several inter-task communication techniques according to their applications. We ported UbiFOS on the ARM9-based DVD player (20 kB), the Calm16-based MP3 player (under 7 kB), and the ATmega128-based ubiquitous sensor node (under 6 kB). Also, we adopted the dynamic power management (DPM) scheme. Comparative experimental results show that UbiFOS could save energy up to 30% using DPM.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2009.05a
• /
• pp.336-339
• /
• 2009

In this paper, such as battery power or solar energy and fuel cells generated from Renewable energy sources, high voltage to low voltage DC-DC Converter for converting the design of the study. System consists of low voltage ($24{\sim}28$ [VDC]) and Boosts the voltage (270 [VDC]) for a 3 [kW] DC-DC converter and control circuit is configured as, Power switch the ST Tomson's Automotive low voltage high current MOSFET switches STE250NS10S (temperature 250A) was applied to the two parallel. Also, Controller's processor used ATMEGA128, and Gate Drive applies and composed Photo Coupler TLP250. development. Input voltage (24V) and output voltage (270V) for Conversion in the H-bridge converter topology of the circuit output side power and voltage to control the implementation of the Phase shift angle control applied. And, 3kW of power to pass appropriate specification of the secondary side as interpreted by the high frequency transformer, and the experimental production and analysis of the experiment

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2008.05a
• /
• pp.209-212
• /
• 2008

During several years, lots of industrial and individual products have been developed based on the text or graphic LCD module which has been gave the short developing period to the developer. With the advent of home networks and intelligent robots, the need for interaction between human and instruments has been increased. Recently, goods with a TFT-LCD come out. But in spite of a simple required performance, the complicated microprocessor, such as ARM processor, is required to interface the TFT-LCD and touch screen. Our research and development is to develope an embedded TFT-LCD module in order to use or apply to the goods through the simple interface by the general users as well as the developers. We adopt the RTOS(real time operating system) in order to operate TFT-LCD independently and various communication protocols are provided in order to offer the simple interface to users and developers.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.6
• /
• pp.1388-1393
• /
• 2007

The Microprocessor Based Laboratory Systems(MBL) with the remote access functional could put basic science experimental facilities together by providing a modem platform that the students can utilize simultaneously to learn basic physics, chemistry and biology, Our educator target platform combines a highly integrated 8-bit embedded Atmega128 processor and real time embedded OS (operating system), allowing plenty of headroom for follow-on basic science projects for students. The proposed MBL-NUTOS (Microprocessor Based Laboratory-NUT/OS) employed in the lab are available with internet base simulation capabilities, on public servers and students personal PCs, enabling the students to study at home and increasing the opportunity of accessing for the science laboratory facility.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.32 no.8B
• /
• pp.509-520
• /
• 2007

In this paper, we propose a real-time sensor node platform that guarantees the real-time scheduling of periodic and aperiodic tasks through a multitask-based software decomposition technique. Since existing sensor networking operation systems available in literature are not capable of supporting the real-time scheduling of periodic and aperiodic tasks, the preemption of aperiodic task with high priority can block periodic tasks, and so periodic tasks are likely to miss their deadlines. This paper presents a comprehensive evaluation of how to structure periodic or aperiodic task decomposition in real-time sensor-networking platforms as regard to guaranteeing the deadlines of all the periodic tasks and aiming to providing aperiodic tasks with average good response time. A case study based on real system experiments is conducted to illustrate the application and efficiency of the multitask-based dynamic component execution environment in the sensor node equipped with a low-power 8-bit microcontroller, an IEEE802.15.4 compliant 2.4GHz RF transceiver, and several sensors. It shows that our periodic and aperiodic task decomposition technique yields efficient performance in terms of three significant, objective goals: deadline miss ratio of periodic tasks, average response time of aperiodic tasks, and processor utilization of periodic and aperiodic tasks.

• The KIPS Transactions:PartC
• /
• v.14C no.4
• /
• pp.371-382
• /
• 2007

In this paper, we propose a real-time sensor node platform that efficiently manages periodic and aperiodic tasks. Since existing sensor node platforms available in literature focus on minimizing the usage of memory and power consumptions, they are not capable of supporting the management of tasks that need their real-time execution and fast average response time. We first analyze how to structure periodic or aperiodic task decomposition in the TinyOS-based sensor node platform as regard to guaranteeing the deadlines of ail the periodic tasks and aiming to providing aperiodic tasks with average good response time. Then we present the application and efficiency of the proposed real-time sensor node platform in the sensor node equipped with a low-power 8-bit microcontroller, an IEEE802.15.4 compliant 2.4GHz RF transceiver, and several sensors. Extensive experiments show that our sensor node platform yields efficient performance in terms of three significant, objective goals: deadline miss ratio of periodic tasks, average response time of aperiodic tasks, and processor utilization of periodic and aperiodic tasks.