text: var tessel = require('tessel'); // import tessel
  var gpio = tessel.port['GPIO']; // select the GPIO port
  
  gpio.digital.forEach(function (pin, i) {
    console.log('Value of digital pin', i, '=', pin.read());
  });
  gpio.analog.forEach(function (pin, i) {
    console.log('Value of analog pin', i, '=', pin.read() * pin.resolution, '/', pin.resolution);
  });
  
  // COMMON = 18 ; G5 ; BLUE ; grounded
  // NORMALLY CLOSED = 19 ; G3 ; GREEN ; not using
  // NORMALLY OPEN = 20 ; G4 ; RED
  
  
  // var COMMON = gpio.pin['G5']; // on GPIO, can be gpio.digital[0] through 5 or gpio.pin['G3'] through ‘G6’
  // COMMON.output(1);
  
  var myPin = gpio.pin['G4']; // on GPIO, can be gpio.digital[0] through 5 or gpio.pin['G3'] through ‘G6’
  myPin.output(1);
  // gpio.pwmFrequency(980);
  
  // myPin.pwmDutyCycle(1.0); // set the pin to be on 60% of the time
  
  function foo(){
  
  
    console.log('Reading pin:', myPin.rawRead());
  
    // foo();
  }
  for(;;){
    setTimeout( foo() , 30000);
  
  }
  
  
  
  // myPin.readPulse('low', 3000, function (err,pulse_len) {
  //   if (err) {
  //     console.log(err.message);
  //     return;
  //   }
  // });
  