For secure basecamp: you'll have to edit mytasks.php and add an s to http in $url ($url = 'https://'.$sitename.'.basecamphq.com/'

Also, if you want to use due dates, edit the mytasks.php

ADD TO foreach($list->{'todo-items'}->{'todo-item'} as $item) LOOP

$item_dueat = $item->{'due-at'};
$dueatCharacters = array(":", "-", "Z");
$item_dueat2 = str_replace($dueatCharacters, "", "$item_dueat");

CHANGE $the_list[] to THIS
$the_list[] = 'DUE:'. $item_dueat2 . "n" . 'SUMMARY:' . $project_name . ' ' . $list_title . ' – ' . $item_text . ' (|'.$item_id.'|'.$list_id.'|'.$project_id.'|)' . "n";

DELETE SUMMARY IN BOTTOM FOREACH LOOP:
BEGIN:VTODO

END:VTODO