text: var tessel = require('tessel'),
      trellis = require('./../index.js')(tessel.port['B'], true),
      fs= require('fs');
  
  trellis.on('error', function(err) {
    console.log(err);
  });
  
  
  
  trellis.ready(function() {
    var up = 1,
        dim = 0;
  
    trellis.clearDisplay();
    setInterval(function() {
      trellis.led(Math.floor(dim / 4), dim % 4).output(up);
      
      if (dim == 15 && up) {
        up = 0;
        return;
      }
      if (dim == 0 && !up) {
        up = 1;
        return;
      }
      trellis.brightness(dim);
      if (up) {
        dim++;
      } else {
        dim--;
      }
  
    }, 50);
  });
  