When I “Pull to refresh”, How I clean the Cache? With Ionic Framework and AngularJS

I have a problem, I'm using a JSON coming from an external server, but when I do "Pull to refresh" or when I open the application, displays the same information I downloaded the first time the application is opened. It may be that the JSON is being stored in the cache and therefore not update? For if when I go to on-refresh = "doRefresh ()" and called another JSON, (the first time I do), update, but re-enter the application I load the information from the first JSON and if I want update, showing me the information I also downloaded the first time. This will fix manually deleting the application data, but it is not the best way ...

This is my services.js

angular.module('starter.services', ['ngResource'])

.factory('NotasService', ['$http',
    function ($http) {

        var items_nota = [];
        var items_nota_array;

        return {

            all: function () {
                return $http.get('http://192.168.1.0:8100/wp-json/posts?filter[post_status]=publish&filter[posts_per_page]=30')
                .success(function(data, status, headers, config){
                  console.log("**** SUCCESS ****");
                  console.log(status);
                })
                .error(function(data, status, headers, config){
                  console.log("**** ERROR ****");
                  console.log(status);
                })
                .then(function(response){
                  console.log("**** THEN ****");

                        items_nota = response;
                        return items_nota;


                  }
                )
            },
            get: function (notaId) {
                // Simple index lookup
                var pepe = parseInt(notaId);

                var ESTO = 0;

                var addToArray = true;
                for (var i = 0; i < items_nota.length; i++) {
                    if (items_nota[i].id == pepe) {
                        addToArray = false;
                        ESTO = i;
                    }
                }


                return items_nota[ESTO];
            }

        }
}])

This is my controller.js..

.controller('ActulidadCtrl', function ($q, $scope, NotasService, $timeout) {

        var items_nota;

        NotasService.all().then(function (data) {
            $scope.items_nota = data;
        })

        //Pull tu refresh
        $scope.doRefresh = function () {
            console.log('Actualizando!');
            $timeout(function () {
                //NotasService.loadData().then(function (data) {
                NotasService.all().then(function (data) {
                    $scope.items_nota = data;
                })

                //Stop the ion-refresher from spinning
                $scope.$broadcast('scroll.refreshComplete');

            });

        };
    })

Thanks! And Happy New Year!