Angular Js: How to send simple data to API using $http?

This is the situation:

I have a simple Angular App that should send some data to API. This data are the email and password taken from a form. Then the API should check if user exist and return true or false.

I am not able to send properly the data to the API.

This is the code: The Controller:

.controller('LoginCtrl', function($scope,$http,$location) {

$scope.submit = function()
{
    console.log('form submitting..');

    $scope.user = {}

    $http({
            method : 'POST',
            url : 'http://localhost/myAppAPI/main/login',
            headers: {'Content-Type': 'application/x-www-form-urlencoded'},
            data: $scope.user
        }).success(function(data) {
            console.log('data(from API): ' + data);

            console.log('user: ' + $scope.user);

            $scope.authorized = data;

            console.log('authorized: ' + $scope.authorized);

            if ($scope.authorized == "true")
            {
                $location.path("/tab/account"); 
            } else 
            {
                $scope.message = "You are not authorized";
            }        

        });



}
})

The form:

<form role="form" method="post" ng-submit="submit()" novalidate>
<div class="list">   
  <label class="item item-input item-stacked-label">
    <span class="input-label">Email</span>
    <input type="text" ng-model="user.email" name="email" placeholder="[email protected]">
  </label>
  <label class="item item-input item-stacked-label">
    <span class="input-label">Password</span>
    <input type="password" ng-model="user.password" name="password" placeholder="Your password">
  </label>
</div>
<input type="submit" id="submit" value="Login" class="button button-block button-positive"/>
</form>

This is the API, made in Codeigniter:

$email = $this->input->post('email');
$password = $this->input->post('password');

if ($email == "test") {

$data = true;
}else {

$data = false;
}

echo json_encode($data);

This is the printing from the console:

user: [object Object]

data(from API): false

authorized: false

So probably the problem can be the the object user i am sending is actually empty. But i should be able to retrieve them using $this->input->post() right?

This is the question:

How can i propely send data to API ın Angular Js using $http ?

Thank you!