Pin.prototype.moveTo = function (pos,time) {                                    
  if (time==undefined) time = 1000;                                             
  var pin = this;                                                               
  var t = 0;                                                                    
  var int = setInterval(function() {                                            
    digitalPulse(pin, 1, 1+Math.clip(pos,0,1));                                 
    t += 20;                                                                    
    if (t>time) clearInterval(int);                                             
  }, 20);                                                                       
};  


var VENT = B12;                                                                 
var WATER = B13;     
                                                           
Pin.prototype.moveTo = function (pos,time) {                                    
  if (time==undefined) time = 1000;                                             
  var pin = this;                                                               
  var amt = 0;                           
  if (servoPos==undefined) servoPos = {};                                         
  if (servoPos[pin]==undefined) servoPos[pin] = pos;

  var int = setInterval(function() {                                          
    if (amt>1) { 
      clearInterval(int);                                               
      servoPos[pin] = pos;
      amt = 1;
    }
    digitalPulse(pin, 1, 1+Math.clip(pos*amt + servoPos[pin]*(1-amt),0,1));                                 
    amt += 1000.0 / (20*time);                                                                    
  }, 20);                                                                       
};      
function ventClose() { VENT.moveTo(0.65, 2000); }                               
function ventOpen() { VENT.moveTo(0.1, 2000); }                                 
function waterOn() { WATER.moveTo(0.9, 2000); }                                 
function waterOff() { WATER.moveTo(0.2, 2000); }