Passing data to a modal with PHP and Ajax

Question

I am creating a system and at a certain moment the user can register the measurements of a person. For this, I would like to redeem in the table of people the ID and the Name, so that they are displayed in the modal, but I am not succeeding, even trying in several ways. I am trying to use Ajax, since to include and delete the information I have already used this tool successfully.

My student consultation table is generated with the following actions:

$tabela .= "\n  <td class='grid' style='width:8%' align='center'>";
$tabela .= "    <button class='btn btn-warning' onclick='_editar($codigo)' type='button'><span class='glyphicon glyphicon-edit'></span></button>";
$tabela .= "</td>";
$tabela .= "\n  <td class='grid' style='width:8%' align='center'>";
$tabela .= "    <button class='btn btn-danger' onclick='_excluir($codigo)' type='button'><span class='glyphicon glyphicon-remove-circle'></span></button>";
$tabela .= "</td>";

Where the code (id) is passed as parameter for the edit exclusion methods.

In _edit I have:

function _editar(varFiltro){
	$('#txtID').val(varFiltro);
	
	$.ajax({
		url: 'index.php?controle=Aluno&acao=editar',
            dataType: 'html',
            type: 'POST',
            data: {
				idAluno: varFiltro
            },
            dataType:"json",
            success: function(data) {
                $('#txtID').val(data["id"]);
                $('#txtNome').val(data["nome"]);  
			}
    });
	$('#frmModal').modal('show');
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>

And on my watch:

    public function editar(){
    $this->modelo('Aluno');

    $idAluno = $_POST['idAluno'];

    $sql  = "select id, nome from aluno where id = $idAluno";

    $result = $this->nome->pesquisar($sql);

    $arr = Array();

    $html = "";

    if($result){
        while($consulta = mysql_fetch_assoc($result)){    
            $arr['id'] = consulta['id'];
            $arr['nome'] = consulta['nome'];
        }
    }

    die(json_encode($arr));

   }

And the view looks like this:

    <div class="modal fade" id="frmModal" tabindex="-1" role="dialog" aria-labelledby="modalLabel" aria-hidden="true" style='max-height: 100%; overflow-y: auto;'>
  <div class="modal-dialog modal-dialog-centered" role="document" style="max-width: 900px;">
    <div class="modal-content">
      <div class="modal-header">
          <table style="width: 100%;">
              <tr  width="100%">
                  <td width="90%">
                       <h3 class="modal-title" id="modalLabel">Cadastro de Medidas</h3>  
                  </td>
                  <td width="10%">
                      <button type="button" class="close" data-dismiss="modal" aria-label="Close">
                        <span aria-hidden="true"><h3>&times;</h3></span>
                      </button>  
                  </td>                            
              </tr>
          </table>
      </div>
      <form id="medida" method="post">
      <div class="modal-body">
            <table class="table table-striped table-bordered table-hover" style="width:100%">
                <tr>
                    <!-- IDENTIFICADOR -->
                    <td class="borda_transparente" style='width:20%'>
                        <div style="width:95%;" class="selectpicker">
                            <label for="txtID">Nº ID</label>
                        </div>
                        <div style="margin-bottom: 10px; width:60%" class="selectpicker">
                            <input class="form-control" type="text" name='txtID' id="txtID" disabled/>
                        </div>
                    </td>

                    <!-- Título do Menu -->
                    <td class="borda_transparente" style='width:100%'>
                        <div style="width:95%;" class="selectpicker">
                            <label for="txtNome">Nome</label>
                        </div>
                        <div style="margin-bottom: 10px; width:95%" class="selectpicker">
                            <input class="form-control" type="text" name='txtNome' id="txtNome" maxlength="40"/>
                        </div>
                    </td>

                </tr>
            </table>    
            </div>
        <div class="modal-footer">
            <button type="button" class="btn btn-success" aria-label="Left Align" onclick="_gravar();"><span class="glyphicon glyphicon-ok" aria-hidden="true" style="margin-right:5px"></span>Gravar</button>          
            <button type="button" class="btn btn-default" data-dismiss="modal">Fechar</button>
        </div>
      </form>
      <div id="mensagemModal"></div>
    </div>
  </div>
</div>

Only the ID is filled, according to the image, the name remains blank: