I have been developing the way in which paper pages connect to the digital. There are various options and I explored each to see which was worked the best.
I used this code snippet in openFrameworks. Magnets are really fun, however they are pretty unreliable and hard to control (it is difficult to place exactly where you are on the screen, and if the screen moves this affects the magnetometer)
For the first version of the book I used OTG (on the go) to connect the hardware to the app directly, and used a system of circuits and switches that triggered the pages. This was great with the android, but now I am developing for ios (only because it is more stable for me to do so, and easier platform to access at the moment…says an android user). Ios does not support OTG very easily
Testing bluetooth + iPad
Sensible Object use an external rfid reader and then communicate to the ipad via bluetooth. I gave this option a go, and got the bluetooth connection working with openFrameworks, but found it very tricky to read the bluetooth signal in my iPad.
This is a simple option (i.e no hardware needed), but requires precision and light.