I ended up creating switches by sticking wire-rigged copper tape on each set of opposing triggerable pages, so that the copper pieces touch each other when the pages are closed, deactivating the audio.

Here’s what my MaxPatcher looks like.  You see the Serial sending the switch readings to the audio objects, telling them to play or not:

  When the copper pieces are not touching, the audio starts playing.

  Simple and effective, this method takes care of most potentially buggy cases that might exist with more complex analog methods (like my original failed attempts to use an FSR to read pressure vs no pressure to see if a page was open (paper is way too light to get an FSR reading), and a Photocell to detect if there is light hitting the page (there is too much light-spill onto closed pages from the top and bottom edges of the book when open).

  So the homemade copper switch proves the simplest, cheapest, AND best solution.  The only problem is that the pages dont always hold perfectly closed unless you are holding the book firmly as you read it.  In future protypes, I would like to add light magnets to the switches to make them a bit more reliable when closed without making it difficult to turn to the page.

  Here’s a video of the prototype in action:

  You can see my effort in holding the pages fully closed as I read, as the switches are often triggered accidentally when turning pages.  This is a huge thing to address as I iterate on this project.

  My plan is to print my own pages with copper built in that run along (almost) the entire top strip of the page.  This way, if any part of the width of 2 closed pages are touching, the audio won’t play.  I will experiment with different patterns to see where the pages most consistently touch.

  I would also like to implement some sort of light magnetism into the sensors to hold them together and address this same problem even more reliably.  I haven’t found a light, suitable magnetic material yet but I will continue to search.  I am taking a Fabrication class next semester so I’m sure I will get new insights on materials and processes of potentially assembling this book in fully-readable form.

  That said, there are a few other things I need to do to take it from prototype to product.  The eventually SoundBook (working title) will have a sensor on every page, so the audio will be totally synced up to the page you’re on at all times.  This will require the thinnest, most compact circuitry possible.

  I want to build the microcontroller into the spine of the book, so figuring out a good way to house it and make it seem as much like a normal book as possible will be critical.  I am excited to continue developing this project, and see much potential in developing my own stories and books built from the ground up to take advantage of this feature.  I could also imagine integrating soundtracks into existing books and releasing them as new editions– reasons to buy physical books again!

  This message has been brought to you by the Society For The Survival Of Literature!  Operation SoundBook: Continue!