title: PHP convert unicode to hex
body: <p>An app wants me to insert strings as <code>text encoded using hex values in proper coding.</code>, the encoding being <code>Unicode_No_Compression</code></p>
  
  <p>For example, for <code>Sześć siedem</code> the correct HEX string is <code>0053007A0065015B0107002000730069006500640065006D</code>,<br>
  <code>Źdźbło</code> = <code>01790064017A00620142006F</code><br>
  <code>String with no special chars</code> 
  =<code>0053007400720069006E0067002000770069007400680020006E006F0020007300700065006300690061006C002000630068006100720073</code></p>
  
  <p>I tried playing with MySQL <code>HEX()</code>/<code>UNHEX()</code> and <code>dechex()</code> PHP, but been unable to figure out how to make this conversion. Any ideas?</p>