Bus Tracking System characterazation presentation

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High Speed Digital Systems Lab
Bus Tracking Systemcharacterazation presentation
Presented by Gal gavish and Yuval
Peled Supervisor Hen Broodney
Winter 2003-2004
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Projects Goals

• Create a system that tracks a bus and gathers the
  arrival times to each station along its route.
• The system includes 3 modules bus, station and
  central-station.
• Communication between bus and stations is done
  using the Bluetooth protocol.

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General System Requirements

• Independent of human intervention.
• Gathers the time of arrival only to stations that
  belong to the buss route.
• Transfers all the data to the central-stations
  database for later analysis.
• Low power consumption.

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Register station
Skip station
Pass information
Register station
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Wireless communication architecture

• We have 2 options for the wireless communication
  between the systems components
• The bus is the Master and stations are slaves.
• At the beginning of the route the bus gets a
  list of all the station-Ids and -frequencies in
  its route. During the ride, it constantly
  searches for the next 2 or 3 stations in its
  list.
• Pros fast connection establishment.

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Wireless communication architecture cont.

• Cons
• a station (slave) cant handle more than one bus
  at a time and if two buses are close one will
  become slave.
• A bus can also somehow miss more than 3 stations
  and then the whole route is lost.
• The bus has to hold a list of stations, therefore
  any change in the route has to be reloaded into
  the memory.

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Wireless communication architecture cont.

• The station is the master and buses are slaves.
• A station searches constantly for oncoming
  buses. When a bus is recognized, the station ID
  is transferred and written in the buss memory
  along with the current time.
• Pros The station can handle several buses
  simultaneously.
• Cons Long connection establishment because of
  the Bluetooth search function.

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Wireless communication architecture cont.

• Bus holds a list of stations in memory
• compares each station ID to the list.
• Advantage Doesnt register unnecessary stations.
• Disadvantage Needs to reload memory whenever
  the route changes.
• Bus doesnt hold a list of stations in memory
• - registers every station ID it receives along
  the route.
• Advantage The bus doesnt need to bother with
  processing the information.
• Disadvantage takes up a lot of memory. Registers
  unnecessary information.

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Memory size calculation

• Assume 2 bytes for the time, 2 bytes for the
  station ID.
• Up to 50 stations in the route 100 interfering
  stations.
• Bus can travel the route up to 8 times before
  returning to the central-station
• Bus holds a list of stations in memory
• 50x(22x8)900 bytes - can be stored in the
  PIC18F built-in memory
• Bus doesnt hold a list of stations in memory
• 150x4x84800 bytes needs an external memory

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Block diagram for the bus and station modules
PIC18F458 microprocessor
Bluetooth
Memory (if needed)
Clock Generator
Battery
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Block diagram for the central-station module
Bluetooth
The info from each bus is transferred to the
computer and stored in a text file.
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Hardware

• Microchip PIC18F458 a 40-pin chip. Later we
  hope to minimize it and use the smallest chip
  suitable (18-pin chip).
• Bluetooth chip.
• Flash memory - component to store info from the
  route.
• Clock generator.
• Battery.

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Stages of the project

• Learning about the developing environment and
  Bluetooth.
• Transferring messages on the Bluetooth.
• Software design.
• Simulation of the entire system on the
  development boards.
• Wire-wrap.
• Debug.
• Optional printed circuits.

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Expected Timetable
Learning
SW design
Simulation
Wire-wrap
Debug
Nov Dec Jan Feb Mar Apr May
Jun Jul
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High Speed Digital Systems Lab
Bus Tracking Systemcharacterization presentation
Presented by Gal Gavish and Yuval
Peled Supervisor Hen Broodney
Winter 2003-2004