Adjust the smoothing parameter w/ the sensor slider value.

notquitefusion.js

var five = require("./lib/johnny-five.js"),
    board, slider;

board = new five.Board();

board.on("ready", function() {
    
  var accel = new five.Accelerometer({
    pins: [ "I0", "I1" ],
    freq: 100
  }); 
  // Create a new `slider` hardware instance.
  slider = new five.Sensor("I3");

  // Fires when value of sensor changes
  //
  slider.scale([ 0, 1 ]).on("slide", function() {
    accel.alpha = this.scaled;
  });
  accel.on("acceleration", function(err, data) {
    console.log(Math.abs(data.rough.x - data.smooth.x));
  });
});