1. Bus Tracking System characterazation presentation Presented by: Gal gavish and Yuval Peled Supervisor: Hen Broodney Winter 2003-2004 High Speed Digital Systems Lab

2. Project’s 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.

3. General System Requirements  Independent of human intervention.  Gathers the time of arrival only to stations that belong to the bus’s route.  Transfers all the data to the central- station’s database for later analysis.  Low power consumption.

4. Register station Skip station Register station Pass information

5. Wireless communication architecture We have 2 options for the wireless communication between the system’s 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.

6. Wireless communication architecture cont. Cons: 1)a station (slave) can’t handle more than one bus at a time and if two buses are close one will become slave. 2)A bus can also somehow miss more than 3 stations and then the whole route is lost. 3)The bus has to hold a list of stations, therefore any change in the route has to be reloaded into the memory.

7. 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 bus’s memory along with the current time. Pros: The station can handle several buses simultaneously. Cons: Long connection establishment because of the Bluetooth search function.

8. Wireless communication architecture cont. Bus holds a list of stations in memory -compares each station ID to the list. Advantage: Doesn’t register unnecessary stations. Disadvantage: Needs to reload memory whenever the route changes. Bus doesn’t hold a list of stations in memory - registers every station ID it receives along the route. Advantage: The bus doesn’t need to bother with processing the information. Disadvantage: takes up a lot of memory. Registers unnecessary information.

9. 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(2+2x8)=900 bytes - can be stored in the PIC18F built-in memory Bus doesn’t hold a list of stations in memory 150x4x8=4800 bytes – needs an external memory

10. Block diagram for the bus and station modules Block diagram for the bus and station modules PIC18F458 microprocessor Bluetooth Memory (if needed) Entriesexits Battery Clock Generator

11. Block diagram for the central-station module Entries exits Bluetooth The info from each bus is transferred to the computer and stored in a text file.

12. 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.

13. 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.

14. Expected Timetable Learning SW design Simulation Debug Wire-wrap Nov Dec Jan Feb Mar Apr May Jun Jul

15. Bus Tracking System characterization presentation Presented by: Gal Gavish and Yuval Peled Supervisor: Hen Broodney Winter 2003-2004 High Speed Digital Systems Lab