PaulOS RTOS Analysis

Abstract

The concept behind a real-time operating system (RTOS) is that of having an operating system which capable of performing real-time application requests. An RTOS can be regarded as a scheduler of tasks which has direct control on the task that is currently running and decides which task should run next. When compared to general purpose operating systems (GPOS), an RTOS provides a higher degree of reliability and timing precision. It provides additional services suited for real-time development and also supports the development process for embedded-systems development [I]. The primary goal of this dissertation was to provide a thorough analysis of a specific RTOS (PaulOS) which was designed by Ing. Paul P. Debono. The system functions of this operating system were systematically divided into separate stand-alone modules. My aim was to make PaulOS more application specific and reduce memory consumption. Analysis regarding the memory and system requirements of each system command was performed. With timing being such an important aspect in RTOSs, the execution time of each system command was documented in this dissertation. To further prove the validity of this real-time operating system for commercial applications, an alarm system was designed and implemented on a C8051F020 microcontroller using PaulOS as the operating system. An LCD module was used as a graphical user interface whilst a 4x4 matrix keyboard was used for security code input. A PIR sensor detects motion by measuring changes in the infrared levels emitted by surrounding objects. A micro-switch simulates the detection of any un-authorised intruders opening doors or windows. To prevent gas leakage accidents, a highly sensitive gas sensor which is capable of detecting LGP, smoke and town gas is used in this system. Apart from the standard siren indicating that the alarm has been triggered, a GSM Siemens TC35 SMS Wireless Module was interfaced with the microcontroller which alerts the user or any other person via an SMS.