1. Bus Tracking System midterm 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. Wireless communication architecture All stations and the central-station are Masters 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. The central-station sends a special message containing data request. The bus sends back all the information it gathered.

5. Specifications Phillips Bluetooth 2.4GHz to 2.4835GHz Operating Frequency Class 2 (0 dBm nominal) Transmit Output Power Up to 15m (with integral antenna)Operating range Less than –80dBm ~ 0.001 BERReceiver Sensitivity Embedded software stack supporting an HCI interface Embedded Software Point to Multipoint (up to 7 slaves) Master/Slave switching supported Network Topology USB v1.1, UART at up to 921 kbps (low voltage serial interface) Interface 3 to 3.4V (or direct power from USB connection)Power Supply Idle: < 2mA File transfer: 70mA Peak: < 100mA Current consumption -10 to + 55°COperating Temperature -40 to + 85°C Storage Temperature 45 x 48 x 7mmDimensions

6. Specifications – Cont. Microchip PIC18F452 DC – 10 MHz Operating Frequency 32KBytesInternal Program Memory 1536 BytesData Memory 256 BytesData EEPROM Memory 18Interrupt Sources 5I/O Ports 4Timers Addressable USART, MSSP MSSP, Serial Communications YesParallel Communications (PSP) 8 input channels10-bit Analog-to- Digital Converter Yes Programmable Low Voltage Detect YesProgrammable Brown-out Reset 75 InstructionsInstruction Set 40-pin DIPPackage

7. Specifications – Cont. Microchip 24LC256 EEPROM 400 KHzMax. Operating Frequency 256K x 8 bits.Data Memory 2.5-5.5 VVcc range 3 mA at 5.5VMax. write current 0.4 mA at 5.5VMax. read current 100 nA at 5.5VTypical standby current 2-wire serial interface bus, I2C™ compatible I/O yesSchmitt Trigger inputs for noise suppression 64 BytePage write mode 5 msMax. write cycle time 1 million write/read cycles Endurance > 4000VElectrostatic discharge protection > 200 yearsData retention -40°C to +85°CTemperature range 8-pin DIPPackage yesHardware write- protect for entire array

8. Block diagram for the bus and station modules PIC18F452 microprocessor Bluetooth Phillips Serial EEPROM Entriesexits Battery 9V Clock Generator 10MHz Development board:

9. Block diagram for the central-station module Bluetooth Phillips The info from each bus is transferred to the computer and stored in a data sheet.

10. Hardware  Microchip PIC18F452 – a 40-pin chip. Later we hope to minimize it and use the smallest chip suitable (18-pin chip).  Bluetooth chip by Phillips.  Serial EEPROM (24LC256) by Microchip - 256K x 8bit.  Clock generator – 10MHz.  Battery – 9V.

11. Memory size calculation Assume 2 bytes for the time, 6 bytes for the station ID. Up to 50 stations in the route + 100 interfering stations. Bus can travel the route up to 10 times before returning to the central- station. Bus writes all stations it passes. 150x8x10=12000 bytes ~ 12Kb Fits inside the 256K EEPROM.

12. EEPROM life expectancy  Serial EEPROMs are typically rated to endure 1 million write operations per byte.  Every time the bus enters the central-station it clears the entire EEPROM memory.  Assume the bus returns to the central-station 20 times a day, 5 days a week. Life_expectancy = 10^6 / (20x5x52) ~ 192 years Before BER increases dramatically.

13. Software design We’ll have 3 main modules: 1.The station module (master). 2.The bus module (slave). 3.The central-station module (master). We’ll also be using modules from a previous project – UART module, LCD module and Bluetooth module.

14. Station module requirements 1.UART – connection to the BT 2.Bluetooth – handle the connection and the data transfer. 3.Connection handling : 1.Search for oncoming buses using the BT inquiry function. 2.Connect to a bus that was found 3.Transfer station ID

15. Bus module requirements 1.UART module 2.BT module 3.Time counter 4.EEPROM 5.Connection handling: 1.Ready bus for connection 2.Block all other connection requests upon connection. 3.Handle data from station. 4.Bus gets out of range of station – disconnect and ready bus for connection to master.

16. Handle data from station 1.Comparing station ID to the last station ID received. 2.Storing station ID in memory 3.Transmitting all the data in memory upon receiving a special data packet containing a request for data.

17. Central-station module 1.BT module on PC. 2.Data sheet 3.Connection handling: 1.Inquiry – search for buses in the vicinity. 2.Connect to a bus that was found. 3.Send data request to bus. 4.Store received data in text file. 5.Disconnect when bus gets out of range

18. Bus module Bluetooth module Station module UART module controls the BT unit LCD module Central-station module Output, debug Interrupt driven

19. Software tools Software tools  We’ll be using the C18 C compiler from the MPLab IDE (Integrated Development Environment) to write our C code for the programs running on the PIC.  We’ll be using the MPLab ICD 2 (In Circuit Debugger) to program the PIC.

20. Debugging tools  To debug the application programmed on the PIC we’ll use the in-circuit debugger (ICD) supplied with the PICDEM 2 Plus development board.  Since debugging with the ICD is slow, we’ll also be using the LCD and the LEDs on the development board for faster and easier debugging.

21. Goals accomplished  Learning about the Bluetooth protocol and the development invironment we’re using.  Reading and understanding the UART, LCD and BT modules code.  Writing our own programs for the bus (slave) and the station (master).  Transferring messages from the station to the bus using the BT units.

22. Next Stages in the project  Learning the Hardware I 2 C and Software I 2 C functions implementing I 2 C bus using I/O pins from the PIC.  Writing to and reading from the EEPROM on the development board.  Simulation of the entire system on the development boards.  Wire-wrap.  Debug.  Optional – printed circuits.

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

24. Next stages I 2 C and EEPROM Simulation Debug Wire-wrap Dec Jan Feb Mar Apr May Jun Jul

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