title: How to separate the character in binary form and checksum them c#
body: <pre><code>ff03c1 3d
  </code></pre>
  
  <p>how to xor this string and get checksum <code>3d</code> ?</p>
  
  <p>the scenario is:</p>
  
  <p>i get string like <code>ff03c13d</code>. (there are other models with longer lengths).
  and i should check crc in hex;</p>
  
  <p>like this:</p>
  
  <p><code>ff</code> xor <code>03</code> xor <code>c1</code> and if result equal the last two characters or the last byte (like <code>3d</code>) return True.</p>
  
  <p>thanks for your help</p>