I’ve written many example programs for Arduino, Processing, p5.js, and node.js, and several Arduino libraries. You can find it all on gitHub. In addition to my own projects, I’ve contributed to Arduino, Arduino-libraries, ITP/NYU, and others.
Some of the more visited repos on my account:
BLEDocs - an introduction to Bluetooth LE, done with Don Coleman, Sandeep Mistry, Alasdair Allan, and video by Jeff Feddersen.
Bluetooth LE Examples - Example code for Bluetooth LE, with code contributed by Sandeep Mistry, Don Coleman, Jingwen Zhu, Yining Shi, and Maria Paula Saba.
Hue Control - an introduction to networked control of Philips Hue lights.
Beginning NFC - code samples for the Beginning NFC book I wrote with Don Coleman and Brian Jepson.
MakingThingsTalk2 - code samples for my book Making Things Talk.
I have additional code examples and explanations on my code blog.