• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.227-235
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• 2011

This paper describes a PMSM control algorithm for realizing a low-cost motor drive system using a general purpose microcontroller. The proposed sensorless algorithm consists of the current observer and the sensorless scheme based on instantaneous reactive power. Also the control board system is not the high-cost DSP(digital signal processor) system but the general purpose microcontroller and it allows to reduce the unit cost of the motor system. However the clock frequency of the proposed microcontroller is one-fifths for the clock frequency of the DSP. In addition, the switching frequency must be selected as the lower frequency because of complex mathematic modeling of the sensorless algorithm. the low switching frequency augments the noise of the motor and might make accurate speed control impossible. Thus this paper proposes the optimization method to supplement the drawback of the general purpose microcontroller and the usefulness of the proposed method is verified through the experiment.

• International Journal of Advanced Culture Technology
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• v.6 no.3
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• pp.129-141
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• 2018

As the scope of social expectations and roles in the design field has expanded, the demand for education to cope with changes in the technology environment is increasing in design education. In response to this trend, microcontroller board-type design-prototyping tools have also been introduced into design education, and much educational content is being developed. However, there is the perception that students who are majoring in design without engineering knowledge are still barred from entry. A variety of educational content and tools have been developed to solve these difficulties, although there are several limitations to their practical application. Especially, in the design education courses in universities, the functional expectation level for prototyping is high, but most of the content developed for solving the difficulties has been developed for the lower education levels, and it could be said that a great deal of learning is necessary to solve the problem. In this study, students were asked about microcontroller board utilization and their satisfaction with their design through questionnaires and with the developed microcontroller board development direction via Focus Group Interviews. Based on this, we tested microcontroller boards that eliminate the coding process and which students can use to create and prototype their work as a suggestion to fulfil demand. After using the board, both the usability and improvement of the product were checked. Confirmation of the usefulness of the free- coding-type microcontroller was obtained through this study along with the possibility of responding to various educational demands by applying the application design related to this product.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4422-4430
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• 2022

Studying the effects of gamma radiation on the instrumentation and control (I&C) system of a nuclear power plant is critical to the successful and reliable operation of the plant. In the accidental scenario, the adverse environment of ionizing radiation affects the performance of the I&C system and it leads to inaccurate and incomprehensible results. This paper reports the effects of gamma radiation on the AT89C51RD2, a commercial-off-the-shelf 8-bit high-performance flash microcontroller. The microcontroller, selected for the device under test for this study is used in the remote terminal unit for a nuclear power plant. The custom circuits were made to test the microcontroller under different gamma doses using a ⁶⁰Co gamma source in both ex-situ and in-situ modes. The device was exposed to a maximum dose of 1.5 kGy. Under this hostile environment, the performance of the microcontroller was studied in terms of device current and voltage changes. It was observed that the microcontroller device can operate up to a total absorbed dose of approximately 0.6 kGy without any failure or degradation in its performance.

• International Journal of Contents
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• v.14 no.3
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• pp.61-68
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• 2018

Unlike in the past, where the expression of the form was given a priority, with the widening of the scopes of the designs, the proportion of design education institution curricula targeting user experience and the application of technology is continually and gradually increasing. Open source microcontroller boards such as Arduino have initiated attracting attention as a countermeasure against these changes. These prototyping tools have many advantages for the diversification of expression and design verification in the design field and therefore have a high likelihood of being introduced into many design education institutes; however, the tools act as high entry barriers for design students who lack engineering knowledge. Although various educational content and tools have been developed to address the issue of barrier, existing solutions remain insufficient as alternatives for the purpose of activation. In this study, we investigated the present state of related education content and conducted a pilot workshop using a prototype microcontroller board with simplified coding. We intend to use the results of this investigation to develop study material for design education. We started by conducting a survey regarding the pre-university education situation. It was observed that engineering education opportunities are insufficient and the problem of mutual application between educations due to course-based education was not realized. We also analyzed the characteristics of simplified training tools using the microcontroller to establish a direction for educational design and conducted a pilot workshop using the microcontroller toolkit with a simplified coding process based on this content. Students who lack a basic knowledge of engineering technology received instruction, and after completing minimum preliminary training, they proceeded to practical exercises that involved utilizing the toolkit. Through this process, we identified the need for a simple-type microcontroller board with low-complexity for use in educating students majoring in design. We also identified some obstacles that serve as barriers to entry of utilizing microcontroller board. Based on these results, we propose several functional requirements and teaching guidelines for prototyping toolkits for design education.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.6
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• pp.148-155
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• 2008

We investigated the damage effects of microcontroller devices under high power electromagnetic(HPEM) wave. HPEM wave was radiated from the open-ended standard rectangular waveguide(WR-340) to free space. The influence of different reset-, clock-, data-, and power supply-line lengths has been tested. The susceptibility of the tested microcontroller devices was in general much influenced by clock-, reset-, and power supply-line length, little influenced by data-line length. Further the line length was increased, the malfunction threshold was decreased as expected, because more energy couples to the devices. The surfaces of the destroyed microcontroller devices were removed and the chip conditions were investigated with microscope. The microscopic analysis of the damaged devices showed component and bondwire destructions such as breakthroughs and melting due to thermal effects.

• Journal of Sensor Science and Technology
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• v.23 no.1
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• pp.24-28
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• 2014

A lock-in amplifier was proposed for capacitive sensor applications. This amplifier was based on a general-purpose microcontroller and had only a charge amplifier as analog circuits. All the other functions of lock-in amplifier except for the charge amplifier were implemented with firmware and the internal resources of the microcontroller. A rectangular signal, generated by the microcontroller, was used in a sensor-driving signal instead of a conventional sinusoidal signal. This makes it possible that the phase comparison circuit in the lockin amplifier is made with analog-to-digital converter, a timer and an interrupt controller. Using the oversampling method and the rectangular driving signal, we can make it easy to implement the peak detection function with software and sample the peak-to-peak signal at charge amplifier output. A charge amplifier was proposed to cancel out the base capacitance existing in capacitive sensors structurally. The experimental results show that the lock-in amplifier operating in the supply voltage of 3.0 V cancels out the base capacitance and has good linearity.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.976-981
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• 2009

This paper proposed optimal design and microcontroller driver for driving the thin-type ultrasonic motor. To find the optimal size of the stator, motions of the motor were simulated using ATILA by changing length, width and thickness of the ceramics. Two sinusoidal waves which have 90 degree phase difference were needed for driving the thin-type motor. The thin-type ultrasonic motor driver was composed of microcontroller(Atmega128), push-pull inverter, encoder and AD-converter. Microcontroller generates four square waves which have variable frequency and 25[%] duty ratio in $20{\sim}150$[kHz]. The output signals of microcontroller were converted to sine wave and cosine wave by push-pull inverter and were applied to the thin-type ultrasonic motor. The encoder and AD-converter were used for maintaining speed of the thin-type ultrasonic motor. The AD-converter controlled DC voltage of inverter in accordance with output signal of encoder. Using the driver, characteristics of the motor as speed and torque were measured.

• Journal of Software Assessment and Valuation
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• v.17 no.1
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• pp.93-99
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• 2021

The demand for online education has rapidly increased due to the influence of COVID-19. One of the biggest challenges in engineering education is how to efficiently conduct experiments online. In this paper, for the virtual experimental system for microcontroller application that is essential for education in the field of electrical, electronic, and control engineering, we described the microcontroller functional modeling and implementation with Java language. The usefulness of the developed microcontroller module has been verified through educational field application.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2263-2268
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• 2008

We investigated the malfunction and destruction characteristics of microcontroller devices under high power electromagnetic(HPEM) wave by magnetron. HPEM was rated at a microwave output of 0 to 1,000 W, at a frequency of 2,450${\pm}$50 MHz and was radiated from the open-ended standard rectangular waveguide(WR-340) to free space. The influence of different reset-, clock-, data-, and power supply-line lengths has been tested. The variation of the line length was done with flat cables. The susceptibility of the tested microcontroller devices was in general much influenced by clock-, reset-, and power supply-line length, little influenced by data-line length. Further the line length was increased, the malfunction threshold was decreased as expected, because more energy couples to the devices. The surfaces of the destroyed microcontroller devices were removed and the chip conditions were investigated with microscope. The microscopic analysis of the damaged devices showed component and bondwire destructions such as breakthroughs and melting due to thermal effects. The obtained results are expected to provide fundamental data for interpreting the combined mechanism of microcontroller devices in an intentional microwave environment.

• Journal of Korea Society of Industrial Information Systems
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• v.27 no.6
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• pp.51-58
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• 2022

Microcontroller (MCU) is designed to properly utilize each module through programming by connecting various modules to Advanced Microcontroller Bus Architecture (AMBA). General-purpose MCUs are designed for consumers to use them appropriately in their research or industry area. However, in a specific area such as networking and AI autonomous vehicles, it is necessary to design MCU suitable for the field directly. However, there is a significant barrier for most consumers to directly design an MCU. In this paper, we provide a development guideline that can easily design an MCU for education or research purpose. First, we introduce AMBA system with open IPs, and we verify that the module operates properly through AMBA and interrupt operation. Finally, the MCU system is designed as an on-chip.