snippet.js

  /**
   * Send a single G-code line, and resolve with the response.
   * @param  {string} line A single line of G-Code
   * @return {Promise} A promise that resolves with the response line, or rejects with the serial error.
   */
  send: function(line) {
    var self = this, port = this.port;
    //Clear any incoming data
    return port.flush()
    //Write the G-code line into the serial port, and set up a waiter with the response.
    .then(function() { return Promise.all([
      port.write(line),
      new Promise(function(res, rej) {
        port.once("data", res);
        setTimeout(function () { port.off("data", res); rej("Timed out waiting for a response"); }, self.options.timeout);
      })
    ]) })
    //and yield with the output line.
    .then(function(results) { return results[0]; });
  }