How to get an IsoTP frame when using a NotifierBasedCanStack?

[starketomyf]

I've been using python-can and python-can-isotp's CanStack in my application to receive IsoTP frames. I used the recv() function like so:

from isotp import CanStack
...
self.__bus = Bus(interface=socketcan, channel=can0, bitrate=baud)

rxid = config.get_pgn_rx()
txid = config.get_pgn_tx()
addr = AddressingMode.Normal_29bits

self.__addr = Address(addr, rxid=rxid, txid=txid)

params = {
    "blocking_send": True,
    "tx_padding": 0xFF,
    "tx_data_min_length": 8,
    "stmin": 20,
}

self.__stack = CanStack(
    self.__bus,
    address=self.__addr,
    error_handler=self.__error_handler,
    params=params,
)
...
message = self.__stack.recv()

I would like to use NotifierBasedCanStack instead. My goal is to have a function as a listener, that receives IsoTP frames. Currently I just have a simple function that prints the incoming messages:

from isotp import CanMessage, NotifierBasedCanStack
...
receiver = self.__notify_can_message
notifier = Notifier(self.__bus, [receiver])
self.__notifier_stack = NotifierBasedCanStack(
    self.__bus,
    notifier,
    address=self.__addr,
    error_handler=self.__error_handler,
    params=params,
)
...
def __notify_can_message(self, message: CanMessage) -> None:
    self.__debug("[RX-CAN] Message notification " + message.data.hex().upper())

When notified, this function receives a CanMessage object. Calling recv() on the stack returns an IsoTP frame, which I would like to have for my NotifierBasedCanStack as well.
What is the recommended way to get the actual IsoTP frame when using NotifierBasedCanStack?

[pylessard]

Hi,
Just use a Listener from python-can instead of providing a function to the notifier. I think what you want is a buffered reader. Then call get_message() to perform a blocking read.

https://python-can.readthedocs.io/en/stable/notifier.html#bufferedreader

Regards