• Journal of the Korea Society of Computer and Information
• /
• v.24 no.11
• /
• pp.21-27
• /
• 2019

Recently, embedded systems have been introduced in various fields such as smart factories, industrial drones, and medical robots. Since sensor data collection and IoT functions for machine learning and big data processing are essential in embedded systems, it is essential to port the operating system that is suitable for the function requirements. However, in embedded systems, it is necessary to separate the hard real-time system, which must process within a fixed time according to service characteristics, and the flexible real-time system, which is more flexible in processing time. It is difficult to port the operating system to a low-performance embedded device such as 8BIT MCU to perform simultaneous real-time. When porting a real-time OS (RTOS) to a low-specification MCU and performing a number of tasks, the performance of the real-time and general processing greatly deteriorates, causing a problem of re-designing the hardware and software if a hard real-time system is required for an operating system ported to a low-performance MCU such as an 8BIT MCU. Research on the technology that can process real-time processing system requirements on RTOS (ported in low-performance MCU) is needed.

• 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 Contents Association Conference
• /
• 2017.05a
• /
• pp.439-440
• /
• 2017

최근 다양한 분야에서 IoT(Internet of Things)를 위한 마이크로 컨트롤러 디바이스가 사용되고 있다. BLE 통신을 통한 전력소모감소로 인해 작은 크기에서 다양한 기능을 수행할 수 있게 되었으며, 이를 위해 마이크로 컨트롤러에서 RTOS가 사용되는 분야가 늘어나고 있다. 본 연구에서는 국내 기술로 개발된 iRTOS를 IoT 디바이스에 포팅하는 연구를 수행한다. Cortex-M 시리즈를 위해 내부 컨텍스트 관리 및 RTOS 타이머 관련 내용을 수정하여 포팅하였다.

• Convergence Security Journal
• /
• v.22 no.1
• /
• pp.99-111
• /
• 2022

With current battlefield environment relying heavily on Network Centric Warfare(NCW), existing weaponary systems are evolving into a new concept that converges IT technology. Majority of the weaponary systems are implemented with numerous embedded softwares which makes such softwares a key factor influencing the performance of such systems. Furthermore, due to the advancements in both IoT technoogies and embedded softwares cyber threats are targeting various embedded systems as their scope of application expands in the real world. Weaponary systems have been developed in various forms from single systems to interlocking networks. hence, system level cyber security is more favorable compared to application level cyber security. In this paper, a secure real-time operating system has been designed, implemented and measured to protect embedded softwares used in weaponary systems from unknown cyber threats at the operating system level.