• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.139-141
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• 2007

This paper presents a digital LCD(Liquid Crystal Display) backlight inverter control using an 8-bit microcontroller. The backlight uses cold cathode fluorescent lamps(CCFLs) that have the negative resistance characteristics, so it requires the ballast function. For this, the proposed LCD backlight inverter uses an 8-bit microcontroller, ATmega128. Therefore, the controller circuit is simplified and cost-minimized. It shows through the experimental results that the proposed inverter has good performance for the LCD backlight inverter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.495-498
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• 2008

This paper describes design of a real-time, wearable reflectance pulse oximetry which is based Wireless Sensor Network. For the purpose of continuously monitoring vital signs of a human, wearable reflectance pulse oximetry is built into a wrist type that can be obtained $SpO_2$ value of patient unobtrusively. This designed $SpO_2$ module is based on a low-power 8 bit ATmega128L microcontroller operating in 3V. Low power operating $SpO_2$ module was integrated to wireless sensor node for user's health monitoring. This paper is focused on the successful integration of all these components into wearable reflectance pulse oximetry and evaluates its ability to measure patient' $SpO_2$ value. Information from this sensor was wirelessly transmitted to a base-station for storage and display purposes.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.126-134
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• 2006

This paper describes the development of an embedded wireless LAN controller which can be in parallel operated with an existing utility controller. The embedded controller mainly consists of Prism(R) 2.5 chip set and Atmega 128 microcontroller. In order to communicate over the network, the controller including TCP/IP stack (IP, TCP, UDP, and ICMP), telnet, and X/Z modem has been developed. For a specific application, we have proposed an special method to convert data structure between TCP/IP and X/Z modem and a data buffer algorithm to minimize the RAM memory usage. Finally, the correctness and performance of the protocols are tested and verified using $CommView^{(R)}\;and\;DU^{(R)}$. The development is satisfactorily operated only for 3,381 bytes of RAM usage without sacrificing interoperability between hosts.

• The KIPS Transactions:PartA
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• v.9A no.1
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• pp.1-8
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• 2002

Most of the traditional embedded web server systems have been designed for monitoring and controlling some dedicated equipments. Hence, not only they have no generality and flexibility but also they are too expensive for the lower-cost domestic equipment. To cope with these difficulty, we suggest a lower-cost ${\mu}$-embedded web server model which is suitable for monitoring and controlling the industry or house equipments by using the internet. The suggested model is based on an one-chip ${\mu}$-processor in which the ISP (In-System Programming) function and flash ROM are embedded basically to minimize the cost of H/W and S/W. Also it allows to add an new function dynamically to provide the generality and flexibility. Finally, to evaluate the feasibility of the suggested model, we have manufactured a test-board based on the ATMega103 ${\mu}$-processor and programmed the control program and tested it on the MS Explorer 5.0 environment.

• Journal of Digital Contents Society
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• v.15 no.4
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• pp.481-489
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• 2014

In this paper, the automatic standby power blocking socket outlet to reduce standby power by blocking power threshold is implemented. Where, the standby power means a flowing power when a disused power electronic is plugged into the socket outlet. The proposed socket outlet can cut off the standby power by establishing a proper block power threshold electronic device according to each electronic device because it can monitor the amount of power through the smart machines such as the real-time PC or mobile phone and directly control the blocking power threshold. The software is implemented by using Visual Studio software, code vision and SN8 C studio, and the hardware is embodied in ATmega128, SN8F27E93S, USB to UART, and relay etc. Through the simulation, we find that the standby power of the proposed method is similar to that of the conventional method in case of the cellular phone but the standby power of the proposed method is much less than that of the conventional method in case of the computer, air conditioning, and set-top box. Therefore, it is proved that the proposed socket outlet has a superior performance in terms of the standby power.

• Journal of the Korea Society of Computer and Information
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• v.17 no.4
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• pp.1-9
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• 2012

As we are turnning into the aged society, accidents by falling down are increasing in the aged people's group. In this paper, we design the system with the 3-Axis acceleration sensor which is composed by a single chip. The body activity signal is measured with the signal detector and RF communicator in this proposed system and the and falling by the entering signal pattern analysis with 3-Axis acceleration sensor. For the RF communication, we are using nRF24L01p and 8bits ATmega uC for the processor. The error of energy expenditure estimation between motor driven treadmill and proposed a body activity module was 7.8% respectively. Human activities and falling is monitored according to analyze and judge the critical value of the Signal Vector. as falled down if they don't turn off the alarm after specific period and the aged person's after falling down activities are their position and more.

• Transactions on Electrical and Electronic Materials
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• v.11 no.5
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• pp.238-241
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• 2010

The purpose of this study is to solve the problems of radio frequency bandwidth frequency depletion, confusion possibilities, and security that are in current wireless communications systems, and to confirm the possibility of applying those solutions for the next generation network. To solve the problems of the current wireless communications system, a visible light communications system for power line communication (PLC) via 8-bit microcontroller is created and the capacity is analyzed. The exclusive PLC chip APLC-485MA, an 8-bit ATmega16 microcontroller, high brightness 5pi light emitting diodes (LEDs), and the LLS08-A1 visible light-receiving sensor were used for the transmitter and receiver. The performance was analyzed using a designed program and an oscilloscope. The voltage change was measured as a function of distance from 10-50 cm. Blue LEDs showed the best performance among the measured LED types, with 0.47 V of voltage loss, but for a distance over 50 cm, precise data was not easy to obtain due to the weak light. To overcome these types of problems, specific values such as the changing conditions and efficiency value relevant to the light emitting parts and the visible light-receiving sensor should be calculated, and continuous study and improvements should also be realized for better communication conditions.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.940_941
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• 2009

Dual Buck Inverter구조를 가지는 70W CDM 램프용 전자식 안정기의 제어기를 설계하였다. 전자식 안정기는 EMI filter, Active PFC, Dual Buck Inverter, Igniter, SMPS로 구성 된다. 제어기는 크게 2개로 구분 할 수 있다. MC33262를 이용하여 Inverter의 전압, 전류를 센싱 받아 70kHz의 Zero Voltage Switching을 위한 제어기와 시간의 경과에 따라 PFC의 출력 전압 제어, Ignition Pulse 제어 및 무부하 보호를 위한 제어기로 구성되어 있다. 본 논문은 ATmega8을 이용하여 제어기를 설계하였고 실험으로 시간의 경광 따른 안정기의 제어가 안정적인 동작을 하고 있음을 증명하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.867-869
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• 2007

TinyOS기반 무선센서노드를 사용한 실시간 계측 데이터 측정 및 제어기술은 유비쿼터스 센서 네트워크 분야에 주로 사용되어 왔으나 다양한 응용이나 신뢰성 있는 무선 네트워크 연구 개발에 한계가 있는 것으로 알려져 있다. 본 논문에서는 ATMega128L을 장착한 최소 8대 이상의 nano-24 센서 노드모듈과 메모리 용량이 매우 제한적인 무선 센서 노드에 적합하다고 평가받고 있는 Nano-Q+를 사용하여 전시물 주변의 환경 정보를 실시간 측정하는 시스템을 구현하였다. 전시물 주변의 센서들은 하나의 PAN Coordinator를 중심으로 Start-Mesh 네트워크를 구성하여 환경 정보를 측정한다. 환경 정보를 전송 하기 위해 측정된 계측 데이터를 센서 네트워크의 PAN Coordinator 노드로부터 환경 모니터링 서버로 효율적으로 전송하기 위한 TCP기반 전송 프로그램을 구현하였다. 실험 결과 센서 노드 수와 관련된 PAN의 크기 및 샘플링 주기에 상관없이 안정적으로 계측 데이터 수신이 이루어짐을 확인 하였다.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.508-510
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• 2005

In this paper, we have studied for the current control method with high accuracy for the high power LED driver that is necessary to the lighting system using LEDs. The control performance of LED driver can be improved with the adjustment of current control boundary by introducing D/A converters for setting high-offset and low-offset. And microprocessor (ATmega128) and D/A converter with 8 bits resolution are used in the proposed driver so that LED's illumination can be remotely controlled by serial communication on the spot or by key input. In the results of performance tests, we confirmed that the proposed control method is superior to the conventional control method using op-amps.