Example sketch how to communicate from a [Particle Photon](https://store.particle.io/#photon) to an [Arduino Uno R3](https://www.arduino.cc/en/Main/arduinoBoardUno) using [Johnny Five](http://johnny-five.io/), [Particle-io](https://github.com/rwaldron/particle-io) and the [Wire](https://www.arduino.cc/en/Reference/Wire) library via [I2C](https://en.wikipedia.org/wiki/I%C2%B2C) protocol.