Some ole fashioned Linux NO-de.js

#!/usr/bin/node

////////////////////////////////////////
//      blinkLED.js
//      Blinks the USR LEDs and P9_14.
//      Wiring: P9_14 connects to the plus lead of an LED.  The negative lead of the
//                      LED goes to a 220 Ohm resistor.  The other lead of the resistor goes
//                      to ground.
//      Setup:
//      See:
////////////////////////////////////////
const fs = require('fs');

let LED1 = "/sys/class/leds/beaglebone:green:usr0/brightness";
//const LED2 = "/sys/class/leds/beaglebone:green:usr1";
//const LED3 = "/sys/class/leds/beaglebone:green:usr2";
//const LED4 = "/sys/class/leds/beaglebone:green:usr3";
//const LED5 = "/sys/class/leds/beaglebone:green:usr4";

// var brightness = [ "/sys/class/leds/beaglebone:green:usr0/brightness", "/sys/class/leds/beaglebone:green:usr1/brightness",
//                   "/sys/class/leds/beaglebone:green:usr2/brightness", "/sys/class/leds/beaglebone:green:usr3/brightness",
//                   "/sys/class/leds/beaglebone:green:usr4/brightness" ];

setInterval(perk, 10000);

function perk() {
  while(1) {
    fs.writeFileSync(LED1, '1', function (err) {
      if (err) return console.log(err);
      console.log('1 > LED1');
    })

    fs.writeFileSync(LED1, '0', function (err) {
      if (err) return console.log(err);
      console.log('0 > LED1');
    })
  }
}