1. Adam Kadolph EE451 Bradley University Advisors: Dr. Irwin, Dr. Schertz
Webtrain Decoupling
Adam Kadolph
EE451
Bradley University
Advisors: Dr. Irwin, Dr. Schertz
Week 1-6
Monday 11/27

2. Outline Project Goals Introduction System Operation Week 1-6 Progress
Weekly Timeline
Sensors Review
Where is the Project Going?

3. Project Goals
The goal of the project is to design a system to automatically decouple cars from the webtrain.
The system will be able to decouple a specific car upon request.
A sensor is used to detect train position

4. Introduction The Webtrain is an N-gauge scale model train.
1 cm wide track
Each locomotive has a special receiver circuit built in
The locomotive can decode DCC Signal sent
Several trains running at various speeds in different direction at once

5. Introduction
The train is controlled through the Digital Command Control (DCC) System
Packets of data sent to train
Data is differential
Packet Structure
14 bits Preamble
8 bits Address Data
8 bits Instruction Data
8 bits Error detection
Transition bits: Packet Start, Data Start, Data Start, Packet End
AAAAAAA DCSSSS 0 EEEEEEEE 1

6. Introduction
The Webtrain Decoupling System is a 4th Generation project for the webtrain.
Webtrain History
2003 Webtrain Built
2004 Web Interface
2006 DCC System and Current Sensing
2007 Decoupling System

7. 2006 DCC System and Current Sensing
Introduction
2006 DCC System and Current Sensing

8. Decouple magnet dimensions – 48 mm x 5 mm x 2 mm (l x w x h)
Introduction
2007 Webtrain Decoupling
Decouple magnet dimensions – 48 mm x 5 mm x 2 mm (l x w x h)

9. System Operation Two modes of decoupling Manual Mode Automatic Mode
User Commands:
Forward
Backward
Stop
Automatic Mode
Car select for decoupling

10. System Operation

11. Week 1-3 Progress Learned Webtrain System Wrote functional description
DCC System
Decoupling
Wrote functional description
Started Website

12. Timeline – Week 1-3

13. Week 4 Progress Spent Morning understanding previous years code
Added plenty of comments in code
Afternoon spent working on my own coding
Implemented new menus
Added corresponding function to menus

14. Timeline – Week 4

15. Week 5-6 Progress Remounted decoupling magnet on bypass lane
Finished coding of manual decoupling aspect of project
Accomplished several decoupling runs
Added 0.5 oz weights to trains to improve control

16. Timeline – Week 5-6

17. Sensors Placement of Sensor Limitation in size
Below track
From sides
From above
Limitation in size
Height can not exceed 2 mm
Width can not exceed 10 mm
Interfaced to a microcontroller

18. Sensors Ambient Light Photosensor Reflective Photosensor
Detection of three levels of ambient light
Analog adjustable gain for levels
Digital Output
Dimensions (4.0mm x 3.2mm x 1.1mm)
Reflective Photosensor
Emitter and Detector in one package
Dimensions (3.4mm x 2.7mm x 1.5mm)
Phototransistor
Fall back sensor
Mounted below track

19. Where is the project going?
Decoupling System
RFID tags
Collision Avoidance

20. Timeline – Semester 1

21. Timeline – Semester 2

22. Bill of Parts Part Quantity Price Total Vendor Decoupler with track 8
$8.00
$64.00
Mike's Scale Rail
Train Cars 5
$15.00
$75.00
Train Wheels 1
$7.95
GP-40 DCC Decoder
$40.00
Atlas
Parts Cabinet
$0.00
Ambient Light Photosensor
$1.75
$8.75
Digikey
Reflective Photosensor
$0.95
$4.75
Phototransistor
$2.38
$11.90
$212.35

23. Questions? Comments.
END