How to submit an unchangeable value with a POST request in CodeIgniter

MySql database is not updating with the new data entered in view. With following the MVC architecture.

My Controller :

public function saveEdit() {
    $this->load->helper('form');
    
    $id = $this->uri->segment(3); 
    
    $save = array(
        'userstory' => $this->input->post('userstoryarea'),
        'datetocomplete' => $this-> input->post('datecomplete'),
        'name' => $this->input->post('developer')
    );
   
    $this->load_userStory->saveEdited($id,$save);
    $this->viewUStory();
}

My Model

public function saveEdited($id,$save)
{   
    $this->db->where('devid', $id);
    $this->db->update('developer', $save);  
}

In some of the places i have called some javascript methods which will return some values to display.

My View

<?php foreach ($story as $UserStory): ?>                
    <form method="post" action="<?php echo base_url() ."addstories/saveEdit"?>" >
        <p> Select Devoloper to add : 
        <select class="form-control" id="developer" name ="developer" style="width:200px;"> </p>
         
         <?php 
            $val2 = $row['name'];
            foreach ($developers as $row)
            { 
                echo '<option value="'.$row->full_name.'" >'.$row->full_name.'</option>';
            }
            ?>
        </select>
        <p>
            
            <p>
            Select a date to complete the project :   <i>

             <input type="date" id="datecomplete"  name ="datecomplete" value="<?php echo $UserStory->datetocomplete;?>" onchange="calculate()">
            </i>    </p>
            
            <p>             
            <input type="textarea" name="userStory" id="userStory" value=" <?php echo $UserStory->userstory; ?> ">
            </p>
            
        <input type="submit" name ="dsubmit" value="Save" id="submit">
    </form>
<?php endforeach; ?>

pass the third value id in action like i pass $id

<form method="post" action="<?php echo base_url() ."addstories/saveEdit/".$id?>" >