code: def _send_char(self,value):
          
  
          if type(value) != str and type(value) != bytes:
              err = "char requires a string or bytes array of length 1"
              raise ValueError(err)
  
          if len(value) != 1:
              err = "char must be a single character, not \"{}\"".format(value)
              raise ValueError(err)
  
          if type(value) != bytes:
              value = value.encode("ascii")
  
          if value in self._escaped_characters:
              err = "Cannot send a control character as a single char to arduino.  Send as string instead."
              raise OverflowError(err)
  
          return struct.pack('c',value)
docs: Convert a single char to a bytes object.