IJARCCE ISSN (Online) 2278-1021 ISSN (Print) 2319 5940 International Journal of Advanced Research in Computer and Communication Engineering ISO 3297:2007 Certified Vol. 6, Issue 8, August 2017 Copyright to IJARCCE DOI10.17148/IJARCCE.2017.6843 248 Study of μCOS RTOS on Low Cost Microcontroller Pundaraja 1 , Lavanya K.J 1 , Priyanka D.L 1 , Priyanka B.V 1 M. Tech Student, Telecommunication Engineering (DCN), Dr. Ambedkar Institute of Technology, Bengaluru, India 1 Abstract: Numbers of RTOS products from various vendors are available in the market, μC/OS-II a freeware with minimum facility is more popular among the hobbyist, researchers and small embedded system developers. In this project LCD is interfaced with the microcontroller using Serial interface. Four tasks are created using μC/OS-II RTOS. Task1 is for manage all other tasks from task create to delete. Task2 for reading characters from key board.Task3 for Displaying the entered characters on Hyper Terminal when ENTER key is pressed. Task4 for Displaying message on LCD when SPACE key is pressed. The software tools SDCC Compiler and ATMEL FLIP tool are used for implementation of tasks using μC/OS-II RTOS on AT89C51ED2 embedded development board. The result obtained indicates that best suitable for small scale industrial automation. Keywords: SDCC, Keil IDE, μC/OS-II RTOS, Flash Magic and Embedded Development Board. I. INTRODUCTION The human effort needed for implementing μC/OS-II RTOS is less compared to other RTOS products. Among the available RTOS μC/OS-II RTOS is suitable for small scale embedded system using various controllers and processors, since it is a freeware and easily available. A micro-kernel operating system (μC/OS-II RTOS) written by John J Lebrosse is a freeware for peaceful research purpose. The source code is written in C language, which is compliant to ANSI „C‟ format. It has about 10,000 lines of source code with well -documented comments in the source code. It is a well-tested source code. The μC/OS-II RTOS supports pre-emptive scheduling and not efficient with respect to processor utilization. The scaled-version of μC/OS-II RTOS on 8051 with multiple tasks uses 4 KB of flash and 512 bytes of RAM. The based on the idea of only placing essential core real-time operating system functions in the kernel is of micro kernal and other functionality is designed in modules that communicate with the kernel via minimal defined interfaces. The results in easy reconfigurable systems without the need to rebuild the kernel in micro kernal. The μC/OS-II kernel is completely designed in software and is a well-used RTOS for combined set of software and hardware systems. It is described in a monolithic microkernel in the language of ANSI C with a small part in assembly language for context switching. The objective of this project is to port μC/OS-II RTOS to 8051 controller and study the performance of multiple tasks. The performance of the 8051 microcontroller respect to different tasks is simulated in software platform and verified in the target hardware. To meet the above objectives, the software tools used for 8051 controller in this work are SDCC (Small device C Compiler ) full version and Atmel Flip2.4.2. The μC/OS-II RTOS is loaded to the system and different tasks are executed. II. PROPOSED WORK Fig. 1: Block diagram of handling of several tasks Hardware Micro-kernel Operating System (μC/OS-II RTOS) Task 1 Task 2 Task 4 Task 3