convert.php

<?php

//mb_internal_encoding("ISO-8859-1");
$encoding = mb_internal_encoding();
echo "internal encoding: " . $encoding . PHP_EOL;

$input = [];
$input[] = chr(197);
$input[] = "\xC5";
$input[] = utf8_encode(chr(197));
//$input[] = utf8_decode(chr(197));

foreach ($input as $i) {
 $encoding = mb_detect_encoding($i);
 $ord = ord($i);
 $unpacked = unpack('H*', $i)[1];
 $bin = chunk_split(str_pad(base_convert($unpacked, 16, 2), 16, 0, STR_PAD_LEFT), 8, " ");

 print_r(Array(
 "\$i" => $i,
 "ord" => $ord,
 "encoding" => $encoding,
 "unpack" => $unpacked,
 "bin" => $bin
 ));
}
echo PHP_EOL;