When you receive data from a sensor, it will be attached to the JavaScript this object, so when you create a callback for the event handler, do not use the arrow syntax, as you will lose the bindings Johnny-Five places on the this object in JavaScript.

Here's an example of a generic data handler for a change event on a Johnny-Five sensor:

let mySensor = new five.Sensor('PIN_NUMBER')

mySensor.on('change', function() {
  console.log(this.value) // logs a value between 0-255 to the console
})

Now that we've established how we'll get the data, let's talk about what the data will look like and how we can manipulate it.