05-03-2011, 10:17 AM
presented by:
Chandrakant Bidave
Chavan Sneha
Bothe Krishna
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ABSTRACT
During the journeys at night times it may fail to know about the outer environment such as vehicle data , place of journey and so on, since the interaction between inner and outer environment is closed.
• In automobiles, the dash boards has many measuring units, such as Pressure gauge, Temperature gauge with numerous cables for inter-connection, which leads to cable complexity, the physical length of cables and other defects in communication.
• To overcome those problems, the CAN Protocol based multiplexed system is proven for the reliability and real-time performance of the data transmitted on CAN bus is appropriate to all Vehicular Automotive applications.
• Vehicle Buses..?
Why buses in vehicles?
Number of electronic equipment is increasing heavily in vehicles (expensive wiring)
Modern vehicles control system needs a lot of information from sensors
Easier fault diagnostic (tester can be connected to a single plug)
• Wire Length
Proposed System will Overcome….
Existing protocols didn’t support multi-masters
Text based communication
Low baud-rates even at higher distances
Poor error detection & management
CAN Networking
KEY CHARACTERISTICS OF CAN
CAN means Controller Area Network
CAN is an asynchronous serial communication protocol
Multi-master concept
o CSMA/CA (Carrier Sense Multiple Access / Collision Avoidance)
Message priority
Object-oriented communication
No node addressing, but content identification
Real-time capability
Low message transfer latency
System wide message consistency
Error detection & management mechanism
Features of ARM Controller
• Philips ARM7TDMI LPC2129 microcontroller with 256 Kbyte program Flash, 16 Kbyte SRAM, and 2 CAN communication channels
• Two interconnected CAN interfaces with advanced acceptance filters & Four channel 10-bit A/D converter with conversion time as low as 2.44 us.
• Vectored Interrupt Controller with configurable priorities and vector addresses.
Features of A/D converter
The LPC2129 contain single 10-bit successive approximation analog to digital converter with four multiplexed channels.
• Measurement range of 0 V to 3 V.
• Capable of performing more than 400,000 10-bit samples per second.
• Burst conversion mode for single or multiple inputs.
• Optional conversion on transition on input pin or Timer Match signal.
Features of LM35
• Calibrated directly in ° Celsius (Centigrade)
• Linear + 10.0 mV/°C scale factor
• 0.5°C accuracy guarantee able (at +25°C)
• Rated for full −55° to +150°C range
• Operates from 4 to 30 volts
• Less than 60 μA current drain
• Low self-heating, 0.08°C in still air
• Nonlinearity only ±1⁄4°C typical
• Low impedance output, 0.1 W for 1 mA load
• The Temperature Sensor
SCHEMATIC OF THE PROJECT
• The engine, water sensor and displacement nodes are continuously monitored on priority basis.
• Engine temperature will be continuously monitored and when maximum heat reaches, the coolant fan will be controlled.
• The water sensor of front glass is monitored to activate the wipers.
• Displacement is measured to display the distance of any obstacle at the back side of the vehicle.
FLOW CHART OF PROJECT IMPLEMENTATION
• A Full-CAN protocol is implemented in a convenient embedded Microcontroller to automate the dash-board display.
• Every node of the CAN bus is controlled by the CAN transceiver MCP2551 chip.
• Each analog inputs are converted to bytes of message like CAN headers and broadcasted to the CAN bus.
• The CAN peripheral automatically scans every incoming CAN message and when an identifier match is detected, the message is copied into the associated received buffer.
Scope of the Project…
Implementation of advanced communication protocols in the automotive and industrial long distance areas will much sophisticated and provides data monitoring with improved efficiency as much as other communication protocols.