string conversion error under python3

[Jeffrey Phillips Freeman]

Traceback (most recent call last):
  File "/usr/lib/python3.4/threading.py", line 920, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.4/threading.py", line 868, in run
    self._target(*self._args, **self._kwargs)
  File "/home/pi/apex/src/apex/buffers.py", line 121, in __run
    read_packet = self.packet_layer.read()
  File "/home/pi/apex/src/apex/aprs/aprs.py", line 201, in read
    frame = self.data_stream.read(*args, **kwargs)
  File "/home/pi/apex/src/apex/kiss/kiss.py", line 200, in read
    self.__fill_buffer()
  File "/home/pi/apex/src/apex/kiss/kiss.py", line 155, in __fill_buffer
    read_data = self._read_interface()
  File "/home/pi/apex/src/apex/kiss/kiss_serial.py", line 73, in _read_interface
    return [ord(c) for c in read_data]
  File "/home/pi/apex/src/apex/kiss/kiss_serial.py", line 73, in <listcomp>
    return [ord(c) for c in read_data]
TypeError: ord() expected string of length 1, but int found