Sensor Workshop

Spring 2012

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Tom's Calendar
Office Hours: See calendar link

Good physical interaction design relies on listening to physical action well. In this class, students will focus on the input side of physical computing by researching various sensors and sensing methods and developing examples for their use. Conceptually, this class sits in between the physical interaction design focus of Intro to Physical Computing, and the electronics focus of Analog Circuits.

Topics include:

  • how to interface sensors to digital systems
  • calibration
  • how to convert the electrical output of a sensor into the terms of the energy it senses
  • computational techniques for interpreting a sensor's datastream
  • datalogging techniques
  • environmental sensing

The class will assemble a library of sensor applications for interactive applications, and apply this research to applications in their classes at ITP.

There will be a number of one-week exercises that students will complete to demonstrate sensor techniques discussed in class. In addition, students will be responsible for a major sensor research project in which they will explain the operating principles of a given sensor and present a working example of the sensor in use. These research projects will be presented throughout the second half of the semester, and collected into an online reference site. There is no final application project, but students will be evaluated on the application of their research (or that of other students) in production projects developed for other classes.

Week 1 - Jan 25

  • What is a sensor?
  • Electronic perception vs. human perception
  • Introduction to the site
  • Code translation: PBasic to Arduino-style C.

Assignment add yourself to the class wiki, with a link to your personal site, as appropriate.
Assignment pick an existing sensor report. Assemble a list of questions, critique, edit. Translate the code sample into Arduino-style C. Work in pairs.

Week 2 - Feb 1

  • Presentation: Present the sensor report you picked. Ask questions, offer critique. Let's talk about what makes these useful, and how we can improve on them.
  • Types of sensors: resistive, capacitive, piezoelectric, MEMS
  • Actives vs Passives
  • Simple device interfaces:
    • voltage output, RC time
    • pulsewidth output
    • serial output
  • Meters, scopes, and logic probes
  • Analog-to-digital and back to analog (voltage conversion)
  • Understanding datasheets

Assignment Manufacturer Description and contact. Work alone on this, so we can maximize our contacts.

Week 3 - Feb 8

  • Sensors and time
    • Input and sampling
    • Graphing voltage over time
    • Averages, Means, and outliers
    • Debouncing and filtering
    • Peaks, Averages, and thresholds
    • Linearity and non-linearity

Assignment Sensor walk
Assignment Sensors and Time. Work alone or in pairs

Week 4 - Feb 15

  • Presentation: Show Sensors and Time results
  • Presentation: Sensor walk results
  • Sensor Interfaces: digital protocols (I2C, SPI)

Assignment Review the sensors you've researched or worked with already. Make sure all notes that you have on them are in the sensor wiki, and add anything new you've discovered.
Assignment choose your final sensor for your report.

Week 5 - Feb 22

  • Datalogging
    • How much data: Sample resolution, sample rate
    • Power and sample rate
  • Logging to a file on an SD card
  • Logging to the network: Pachube and other options

Assignment Datalogging
Assignment review one other person's choice, to see if there is already significant data in the wiki. Suggest a plan of action for them. I'll assign your partners.

Week 6 - Feb 29

  • Hardware filtering
    • Decoupling
    • Op Amps

Assignment: consider the reviews by others and make a plan of action for your sensor report.

Spring Break - Mar 14

Week 7 - Mar 21

  • Presentation: tell us your final sensor choice, and give us your plan of action.
  • Events, actions, and filtering

Assignment Events, actions, and filtering

Week 8 - Mar 28

  • Presentation: Actions, Events, and filtering
  • Topics TBA depending on sensor report needs

Week 9 - April 3 - Makeup class

Week 10 - Apr 4

Week 11 - Apr 11

Week 12 - Apr 18

Week 13 - Apr 25

Week 14 - May 2

  • Wrap-up, review, final questions, plans for the future

Grading & Policies

Participation & Attendance

Showing up on time, engaging in the class discussion, and offering advice and critique on other projects in the class is a major part of your grade. Please be present and prompt. Lateness will hurt your grade. If you're going to be late or absent, please email your instructor in advance. If you have an emergency, please let your instructor know as soon as you can. Please turn in assignments on time as well.

Grading:

  • Participation & Attendance: 20%
  • Minor Assignments: 20%
  • Sensor research presentation: 25%
  • Documentation: 20%
  • Outside application: 15%

Laptops

Laptop use is fine if you are using your laptop to present in class, or if we're in the middle of an exercise that makes use of it. Whenever classmates are presenting or we're in the midst of a class discussion, however, please keep your laptop closed. The quality of the class depends in large part on the quality of your attention and active participation, so please respect that and close your lid.

Mobile Phones

Please put them on vibrate or turn them off before you come to class unless they are part of your project. If you have an emergency that requires you to answer your phone during class, please tell your instructor ahead of time.


Parts & Books

Parts

The parts you used for intro to physical computing should get you started. Any additional parts will be determined by what sensors you choose to work with.

Books

Below are recommended texts for the course in general.

Physical Computing: Sensing and Controlling the Physical World with Computers, Dan O’Sullivan and Tom Igoe ©2004, Thomson Course Technology PTR; ISBN: 159200346X Includes much of the material covered in class and lots of advanced examples as well.

Make: Electronics, Charles Platt, © 2009 Make Books, Sebastapol, CA; 1st edition ISBN: 0596153740. An excellent intro to electronics. Practical, readable, and enjoyable. Start here.

Getting Started in Electronics, Forrest M. Mims III, ©1983, Forrest M. Mims III A very basic introduction to electricity and electronics, written in notebook style. Includes descriptions of the basic components and what they do, and how they relate to each other.

Practical Electronics for Inventors, 2nd Edition. Paul Scherz, ©2006, McGraw-Hill Professional Publishing; ISBN: 978-0071452816 A more in-depth treatment of electronics, with many practical examples and illustrations. An excellent reference for those comfortable with the basic topics. The use of plumbing systems as examples to demonstrate electric principles makes for some very clear illustrations of how different components work. Good chapters on sound electronics and motors as well.

The Art of Electronics, 2nd Edition. Paul Horowitz & Winfield Hill ©1989, Cambridge University Press, ISBN 0-521-37095-7 For more advanced coverage of electronics, but still accessible to the non-engineeer, this is an invaluable reference. Not as accessible as Practical Electronics (above), but more in-depth on some topics.

Build Your Own Printed Circuit Board, Al Williams, ©2003, McGraw-Hill/TAB Electronics. ISBN 639785506973 The title says it all. This book introduces how circuit boards are made, how you design them using specialized CAD software, and how to fabriacte them at home or to get them manufactured professionally. A good introduction to the process.


Past Syllabi

Spring 2008
* Jeff Gray's Class

Spring 2007
* Jamie Allen's Class

Fall 2005 / Spring 2006
* Tom Igoe's Class