Reading mixed ASCII/binary serial input

[N8UR]

I think I figured it out. This seems to work with a timeout of 1 second:

    self.serial.timeout = 1
    delimiter = b'$PASHR'
    if self.serial.in_waiting:
        message = self.serial.read_until(delimiter)
        if len(message) > 6: # ignore carryover b'$PASHR'
            ***process message***

When I looked carefully at the variable length returns, I discovered that the message sequence after the first incomplete cycle was:

b'$PASHR' (6 bytes)
b',MPC,<data><checksum>\r\n$PASHR' (108 bytes)
...
b',MPC,<data><checksum>\r\n' (102 bytes)
(delay)
b'$PASHR' (6 bytes)

The delimiter from the last message in the sequence is chopped off and output at the beginning of the next sequence. I can deal with that.