var barcode = {
  listenerObj: null,
  oneKeyTime : '', /* 一次按键时间间隔 */
  twoKeyTime : '', /* 两次按键时间间隔 */
  keyDownTime: '', /* 键按下的时间  */
  barcodeLen : 8 , /* 条形码长度   */
  spanTime  : 70, /* 一次按键按下到释放的时间间隔 */
  on_key_down : function (){
    var that = this;
    this.listenerObj.keydown(function(e){
      if(e.which !== 13 && !(that.in_range(e.which))){
        $(that.listenerObj).val('');
        return ;
      }
      var d = new Date();
      var curTime = parseInt(d.getTime());
      if(that.keyDownTime !== '' && that.keyDownTime !== NaN){
        that.twoKeyTime = curTime - that.keyDownTime;
      }
      that.keyDownTime = curTime;
    });
  },
  on_key_up : function(){
    var that = this;
    this.listenerObj.keyup(function(e){
      var d = new Date();
      var keyUpTime = d.getTime();
      that.oneKeyTime = parseInt(keyUpTime) - parseInt(that.keyDownTime);
      var isHand = that.checkHandInput();
      if(isHand && that.in_range(e.which)){
        layer.msg('禁止手动输入');
        $(that.listenerObj).val("");
      }
    })
  },
  on_key_press : function(){
    var that = this;
    this.listenerObj.keypress(function(e){
      if(e.which == 13 && that.check_barcode()){
        that.createListEl();
      }
    });
  },
  checkHandInput : function(){
    if((this.oneKeyTime > this.spanTime) || this.twoKeyTime > this.spanTime){
      return true;
    }else{
      return false;
    }
  },
}

<input id="barCode" value="" type="text" placeholder="stay focus" style="" name="">
$("#barCode").startListen({
  barcodeLen : 10,
  letter : true,
  number : true,
  show : function(code){
    layer.msg(code);
  }
});