Doubt in PHP Paging

Question

I’m working on a system and I’m having doubts in the pagination, I know it can have some grotesque errors because not "manjo" much.

<?php include("cabecalho.php");
include("conexao.php"); 
include("banco-dados.php"); 

    $totalReg = 11;
?>


<?php
    //$pagina = (isset($_GET['pagina']))? $_GET['pagina'] : 1;
    $pagina = $_GET['pagina']; 

    if (!$pagina) { 
        $pc = "1"; 
    } else { 
        $pc = $pagina; 
    } 

?>
<?php
    $inicio = $pc -1
?>



<?php if(array_key_exists("removido", $_GET) && $_GET['removido'] == true) : ?>
    <p class="alert-success">Chip apagado com sucesso</p>
<?php 
    endif
 ?>

<?php if(array_key_exists("add", $_GET) && $_GET['add'] == true) : ?>
    <p class="alert-success">Chip adicionado com sucesso</p>
<?php 
    endif
 ?>

 <?php if(array_key_exists("altera", $_GET) && $_GET['altera'] == true) : ?>
    <p class="alert-success">Chip alterado com sucesso</p>
<?php 
    endif
 ?>
<table class="table2 table-striped table-bordered">
    <form action="lista-chip.php" method="post">
        <tr>
            <td class="col-md-1"><input class="form-control" type="text" placeholder="Busca pelo o ddd" name="ddd"></td>
            <td class="col-md-2"><input class="form-control" type="text" placeholder="Busca pelo o telefone" name="telefone"></td>
            <td class="col-md-2"><input class="form-control" type="text" placeholder=" Busca pela a operadora" name="operadora"></td>
            <td class="col-md-1"><input class="btn btn-default" type="submit"> </td>
        </tr>
    </form>
    <tr>
        <td><h5><strong>DDD</strong></h5></td>
        <td><h5><strong>TELEFONE</strong></h5></td>
        <td><h5><strong>OPERADORA</strong></h5>
        <td><h5><strong>STATUS</strong></h5></td>
        <td><h5><strong>FUNÇÕES</strong></h5>

    </tr>
    <?php
        $inicio = $pc - 1; 
        $inicio = $inicio * $totalReg;


        $chips = listaChips($conexao, $inicio, $totalReg);
        foreach($chips as $chip) :
    ?>
    <tr>
        <td><?= $chip['DDD']; ?></td>
        <td><?= $chip['TELEFONE']; ?></td>
        <td><?= $chip['operadora_nome']; ?></td>
        <td> <?= $chip['STATUS'] != 1 ? "Desativo" : "Ativo"; ?> </td>
        <td class="col-md-1">
            <a href="lista-chip.php?id=<?=$chip['ID_CHIP']?>"><img src="imgs/atualizar.png"></a>
            <a href="editar-chip.php?id=<?=$chip['ID_CHIP']?>"><img src="imgs/edit.png"></a>
            <a onclick="return confirm('Você tem certeza que quer excluir esse item?');" href="remove-chip.php?id=<?=$chip['ID_CHIP']?>"><img src="imgs/remover.png"></a>
        </td>
    </tr>

    <?php
        endforeach  
    ?>
</table>
<?php

?>  <div class="btn-group">
        <button type="button" class="btn btn-default"><a href="chips.php?pagina='$anterior'">  Anterior</a> </button>
        <button type="button" class="btn btn-default"><a href="chips.php?pagina='$proximo'">Próxima</br></a> </button>
    </div>


<?php include("rodape.php"); ?>

when I click the button next, the following error appears

Warning: mysqli_fetch_assoc() expects Parameter 1 to be mysqli_result, Boolean Given in C: xampp htdocs managed database.php on line 25

down the function,with line 25. Someone helps me to make the system correctly apgination?