Try to use this function, where $text is your text to split and $choplenght (optional) is the lenght of the peices of the $text string. The command for using this function is:
array = string2array(string, int);
string2array.php
//========================================
function string2array($text, $choplenght = 1) {
for($i = 0; $i < strlen($text); $i = $i + $choplenght){
$chunk = substr($text, $i, $choplenght);
$text_array[] = $chunk;
}
return $text_array;
}
//========================================