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 0 01DCSSSS 0 EEEEEEEE 1

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

7 Introduction 2006 DCC System and Current Sensing

8 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 User Commands: –Forward –Backward –Stop –Automatic Mode User Commands: –Car select for decoupling

10 System Operation

11 Week 1-3 Progress Learned Webtrain System –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 –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 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 PartQuantityPriceTotalVendor Decoupler with track8$8.00$64.00Mike's Scale Rail Train Cars5$15.00$75.00Mike's Scale Rail Train Wheels1$7.95 Mike's Scale Rail GP-40 DCC Decoder1$40.00 Atlas Parts Cabinet1$0.00 Ambient Light Photosensor5$1.75$8.75Digikey Reflective Photosensor5$0.95$4.75Digikey Phototransistor5$2.38$11.90Digikey $212.35

23 Questions? Comments. END