International Journal of Computer Applications (0975 – 8887) Volume *– No.*, ___________ 2014 39 Efficient Low-power Scanner Free On-Board Diagnostics and Monitoring System for Vehicles S. Sheraz Mohani Dept. of Engineering, Sciences & Technology, Iqra University, Karachi M. Waseem Dept. of Telecom. Engg, Sir Syed University of Engineering & Technology Karachi, Pakistan Mir Asif Dept. of Electronic Engg, Sir Syed University of Engineering & Technology, Karachi, Pakistan Zeeshan Asim Dept. of Electronic Engg, Sir Syed University of Engineering & Technology, Karachi, Pakistan ABSTRACT The diagnostics and monitoring of the running condition of a car engine is very important and smart way to enhance the efficiency and maintenance of the engine. In the modern era almost all modern vehicles include an On Board Diagnostic (OBD) system. The OBD system can always monitor the running condition of engine. When the OBD system detects a malfunction in any of sensors or engine parameters, OBD regulations require the Electronic Control Unit (ECU) of the vehicle to save a standardized Diagnostic Trouble Code (DTC) about the information of malfunction in the memory. These DTC’s can be processed and read by connecting external scanner to OBD system which then shows the diagnostic results. But this project removes the need of external scanner. The purpose of this study is to make the information of different sensors of engine and parameters of vehicle freely available to drivers or mechanics on an embedded screen device. This system eliminates the need of any external scanner required to show the diagnostic results of OBD system and solves these problems by providing many useful functions such as real time display of sensor data, diagnostic trouble code (DTC) reading and displaying information of different sensors and parameters of engine in a simple and an easily understandable language for the user (driver). General Terms Monitoring system, On-board diagnostics, vehicle engine monitoring. Keywords Model-based diagnosis, On-board diagnostics system, vehicle parameters monitoring. 1. INTRODUCTION On-Board Diagnostics, or OBD, in an automotive context, is a generic term referring to a vehicle's self-diagnostic and reporting capability. OBD systems give the vehicle owner or a repair technician access to state of health information for various vehicle sub-systems. OBD system consists of a computer chip interfaced with different sensors in the car. These sensors update their information to the controller in OBD system that transfers this data in the form of DTC’s (Diagnostic Troubleshooting Codes). This data is then read by the scan tool. Early instances of OBD would simply illuminate a malfunction indicator light, or MIL, if a problem was detected—but would not provide any information as to the nature of the problem. Modern OBD implementations use a standardized fast digital communications port to provide real time data of sensors, DTC’s, which allow one to rapidly identify and remedy malfunctions within the vehicle. But this is achieved by connecting an external scanning tool which is an expensive device and it is not easily decodable in simple language by an owner or a car technician. Comprehensive description of the DTC is done by using software on a PC or laptop. The aim of the research is focused to design a low cost and low power diagnostic system for vehicles that can monitor the status and process real time data of engine parameters and sensors connected, and also display its status and information on LCD in an easy and understandable language for the user of the vehicle. The proposed system is so designed that it must eliminate the need of any external scanning tool or connection to a PC or laptop. Moreover, the proposed system should be capable of extracting the necessary data from the vehicle in order to use it in a meaningful and useful way by using the mounted sensors. 2. SYSTEM BLOCKS The building blocks of the proposed diagnostics system model are explained in this section. The backbone of the system is considered to be the communication with the system done using the custom protocols on serial transmission; and the firmware is based on C programming. The system takes sensor-data and sends it to a master controller using a distinct frame format used for identification and information, the data contains. The OBD (on board diagnostic) frameworks made are perplexing and oblige outer scanner interfaced with no constant powerful implication of the glitch in the vehicle, so the thought is to actualize a prototype framework which gives the client continuous data of the breakdown and which is straightforward. The utilization of DTC's (symptomatic inconvenience codes) will be carried out on inner level and the client is demonstrated the issue in a basic dialect on a showcase. Sensors that are really basic for a legitimate vehicle working will be interfaced including fuel level, temperature, alternator sensing, brake oil level, clutch check, state of brakes and radiator fan state are vital things to be incorporated. In the proposed model AVR series of microcontrollers is used, which contain built-in peripheral UART and ADC. The initialization and selection of modes for both the peripherals according to the requirement is to be achieved before any further work can be done. The on-board UART in the AVR is