def _data_transfer_handler(self, msg):
msg_source = msg.arbitration_id.source_address
pdu_specific = msg.arbitration_id.pgn.pdu_specific
if msg_source in self._incomplete_received_pdus:
if pdu_specific in self._incomplete_received_pdus[msg_source]:
self._incomplete_received_pdus[msg_source][
pdu_specific].data.extend(msg.data[1:])
total = self._incomplete_received_pdu_lengths[msg_source][
pdu_specific]["total"]
if len(self._incomplete_received_pdus[msg_source]
[pdu_specific].data) >= total:
if pdu_specific == constants.DESTINATION_ADDRESS_GLOBAL:
# Looks strange but makes sense - in the absence of explicit flow control,
# the last CAN packet in a long message *is* the end of message acknowledgement
return self._process_eom_ack(msg)
# Find a Node object so we can search its list of known node addresses for this node
# so we can find if we are responsible for sending the EOM ACK message
send_ack = any(True for l in self.j1939_notifier.listeners
if isinstance(l, Node) and (
l.address == pdu_specific
or pdu_specific in l.address_list))
if send_ack:
arbitration_id = ArbitrationID()
arbitration_id.pgn.value = constants.PGN_TP_CONNECTION_MANAGEMENT
arbitration_id.pgn.pdu_specific = msg_source
arbitration_id.source_address = pdu_specific
total_length = self._incomplete_received_pdu_lengths[
msg_source][pdu_specific]["total"]
_num_packages = self._incomplete_received_pdu_lengths[
msg_source][pdu_specific]["num_packages"]
pgn = self._incomplete_received_pdus[msg_source][
pdu_specific].arbitration_id.pgn
pgn_msb = ((pgn.value & 0xFF0000) >> 16)
_pgn_middle = ((pgn.value & 0x00FF00) >> 8)
_pgn_lsb = 0
div, mod = divmod(total_length, 256)
can_message = Message(
arbitration_id=arbitration_id.can_id,
extended_id=True,
dlc=8,
data=[
constants.CM_MSG_TYPE_EOM_ACK,
mod, # total_length % 256,
div, # total_length / 256,
_num_packages,
0xFF,
_pgn_lsb,
_pgn_middle,
pgn_msb
])
self.can_bus.send(can_message)
return self._process_eom_ack(msg)
def test_simple_periodic_send():
print("Trying to send a message...")
msg = Message(arbitration_id=0x0cf02200, data=[0, 1, 3, 1, 4, 1])
task = can.send_periodic('vcan0', msg, 0.020)
time.sleep(2)
print("Trying to change data")
msg.data[0] = 99
task.modify_data(msg)
time.sleep(2)
task.stop()
print("stopped cyclic send")
time.sleep(1)
task.start()
print("starting again")
time.sleep(1)
print("done")
def test_simple_periodic_send():
print("Trying to send a message...")
msg = Message(arbitration_id=0x0cf02200, data=[0, 1, 3, 1, 4, 1])
task = can.send_periodic('vcan0', msg, 0.020)
time.sleep(2)
print("Trying to change data")
msg.data[0] = 99
task.modify_data(msg)
time.sleep(2)
task.stop()
print("stopped cyclic send")
time.sleep(1)
task.start()
print("starting again")
time.sleep(1)
print("done")
def test_dual_rate_periodic_send():
"""Send a message 10 times at 1ms intervals, then continue to send every 500ms"""
msg = Message(arbitration_id=0x0c112200, data=[0, 1, 2, 3, 4, 5])
print("Creating cyclic task to send message 10 times at 1ms, then every 500ms")
task = MultiRateCyclicSendTask('vcan0', msg, 10, 0.001, 0.50)
time.sleep(2)
print("Changing data[0] = 0x42")
msg.data[0] = 0x42
task.modify_data(msg)
time.sleep(2)
task.stop()
print("stopped cyclic send")
time.sleep(2)
task.start()
print("starting again")
time.sleep(2)
print("done")
def test_dual_rate_periodic_send():
"""Send a message 10 times at 1ms intervals, then continue to send every 500ms"""
msg = Message(arbitration_id=0x0c112200, data=[0, 1, 2, 3, 4, 5])
print(
"Creating cyclic task to send message 10 times at 1ms, then every 500ms"
)
task = MultiRateCyclicSendTask('vcan0', msg, 10, 0.001, 0.50)
time.sleep(2)
print("Changing data[0] = 0x42")
msg.data[0] = 0x42
task.modify_data(msg)
time.sleep(2)
task.stop()
print("stopped cyclic send")
time.sleep(2)
task.start()
print("starting again")
time.sleep(2)
print("done")
def _process_rts(self, msg):
if msg.arbitration_id.source_address not in self._incomplete_received_pdus:
self._incomplete_received_pdus[
msg.arbitration_id.source_address] = {}
self._incomplete_received_pdu_lengths[
msg.arbitration_id.source_address] = {}
# Delete any previous messages that were not finished correctly
if msg.arbitration_id.pgn.pdu_specific in self._incomplete_received_pdus[
msg.arbitration_id.source_address]:
del self._incomplete_received_pdus[
msg.arbitration_id.source_address][
msg.arbitration_id.pgn.pdu_specific]
del self._incomplete_received_pdu_lengths[
msg.arbitration_id.source_address][
msg.arbitration_id.pgn.pdu_specific]
if msg.data[0] == constants.CM_MSG_TYPE_BAM:
self._incomplete_received_pdus[
msg.arbitration_id.source_address][0xFF] = self._pdu_type()
self._incomplete_received_pdus[msg.arbitration_id.source_address][
0xFF].arbitration_id.pgn.value = int(
("%.2X%.2X%.2X" % (msg.data[7], msg.data[6], msg.data[5])),
16)
if self._incomplete_received_pdus[
msg.arbitration_id.source_address][
0xFF].arbitration_id.pgn.is_destination_specific:
self._incomplete_received_pdus[msg.arbitration_id.source_address][
0xFF].arbitration_id.pgn.pdu_specific = msg.arbitration_id.pgn.pdu_specific
self._incomplete_received_pdus[msg.arbitration_id.source_address][
0xFF].arbitration_id.source_address = msg.arbitration_id.source_address
self._incomplete_received_pdus[
msg.arbitration_id.source_address][0xFF].data = []
_message_size = int("%.2X%.2X" % (msg.data[2], msg.data[1]), 16)
self._incomplete_received_pdu_lengths[
msg.arbitration_id.source_address][0xFF] = {
"total": _message_size,
"chunk": 255,
"num_packages": msg.data[3],
}
else:
self._incomplete_received_pdus[msg.arbitration_id.source_address][
msg.arbitration_id.pgn.pdu_specific] = self._pdu_type()
self._incomplete_received_pdus[msg.arbitration_id.source_address][
msg.arbitration_id.pgn.
pdu_specific].arbitration_id.pgn.value = int(
("%.2X%.2X%.2X" % (msg.data[7], msg.data[6], msg.data[5])),
16)
if self._incomplete_received_pdus[msg.arbitration_id.source_address][
msg.arbitration_id.pgn.
pdu_specific].arbitration_id.pgn.is_destination_specific:
self._incomplete_received_pdus[msg.arbitration_id.source_address][
msg.arbitration_id.pgn.
pdu_specific].arbitration_id.pgn.pdu_specific = msg.arbitration_id.pgn.pdu_specific
self._incomplete_received_pdus[msg.arbitration_id.source_address][
msg.arbitration_id.pgn.
pdu_specific].arbitration_id.source_address = msg.arbitration_id.source_address
self._incomplete_received_pdus[msg.arbitration_id.source_address][
msg.arbitration_id.pgn.pdu_specific].data = []
_message_size = int("%.2X%.2X" % (msg.data[2], msg.data[1]), 16)
self._incomplete_received_pdu_lengths[
msg.arbitration_id.source_address][
msg.arbitration_id.pgn.pdu_specific] = {
"total": _message_size,
"chunk": 255,
"num_packages": msg.data[3],
}
if msg.data[0] != constants.CM_MSG_TYPE_BAM:
for _listener in self.j1939_notifier.listeners:
if isinstance(_listener, Node):
# find a Node object so we can search its list of known node addresses
# for this node - if we find it we are responsible for sending the CTS message
if _listener.address == msg.arbitration_id.pgn.pdu_specific or msg.arbitration_id.pgn.pdu_specific in _listener.address_list:
_cts_arbitration_id = ArbitrationID(
source_address=msg.arbitration_id.pgn.pdu_specific)
_cts_arbitration_id.pgn.value = constants.PGN_TP_CONNECTION_MANAGEMENT
_cts_arbitration_id.pgn.pdu_specific = msg.arbitration_id.source_address
_data = [0x11, msg.data[4], 0x01, 0xFF, 0xFF]
_data.extend(msg.data[5:])
cts_msg = Message(
extended_id=True,
arbitration_id=_cts_arbitration_id.can_id,
data=_data,
dlc=8)
# send clear to send
self.can_bus.send(cts_msg)
return
def send(self, msg):
messages = []
if len(msg.data) > 8:
# Making a copy of the PDU so that the original
# is not altered by the data padding.
pdu = copy.deepcopy(msg)
pdu.data = bytearray(pdu.data)
pdu_length_lsb, pdu_length_msb = divmod(len(pdu.data), 256)
while len(pdu.data) % 7 != 0:
pdu.data += b'\xFF'
for i, segment in enumerate(pdu.data_segments(segment_length=7)):
arbitration_id = copy.deepcopy(pdu.arbitration_id)
arbitration_id.pgn.value = constants.PGN_TP_DATA_TRANSFER
if pdu.arbitration_id.pgn.is_destination_specific and \
pdu.arbitration_id.destination_address != constants.DESTINATION_ADDRESS_GLOBAL:
arbitration_id.pgn.pdu_specific = pdu.arbitration_id.pgn.pdu_specific
else:
arbitration_id.pgn.pdu_specific = constants.DESTINATION_ADDRESS_GLOBAL
message = Message(arbitration_id=arbitration_id.can_id,
extended_id=True,
dlc=(len(segment) + 1),
data=(bytearray([i + 1]) + segment))
messages.append(message)
if pdu.arbitration_id.pgn.is_destination_specific and \
pdu.arbitration_id.destination_address != constants.DESTINATION_ADDRESS_GLOBAL:
destination_address = pdu.arbitration_id.pgn.pdu_specific
if pdu.arbitration_id.source_address in self._incomplete_transmitted_pdus:
if destination_address in self._incomplete_transmitted_pdus[
pdu.arbitration_id.source_address]:
logger.warning(
"Duplicate transmission of PDU:\n{}".format(pdu))
else:
self._incomplete_transmitted_pdus[
pdu.arbitration_id.source_address] = {}
self._incomplete_transmitted_pdus[
pdu.arbitration_id.
source_address][destination_address] = messages
else:
destination_address = constants.DESTINATION_ADDRESS_GLOBAL
rts_arbitration_id = ArbitrationID(source_address=pdu.source)
rts_arbitration_id.pgn.value = constants.PGN_TP_CONNECTION_MANAGEMENT
rts_arbitration_id.pgn.pdu_specific = pdu.arbitration_id.pgn.pdu_specific
temp_pgn = copy.deepcopy(pdu.arbitration_id.pgn)
if temp_pgn.is_destination_specific:
temp_pgn.value -= temp_pgn.pdu_specific
pgn_msb = ((temp_pgn.value & 0xFF0000) >> 16)
pgn_middle = ((temp_pgn.value & 0x00FF00) >> 8)
pgn_lsb = (temp_pgn.value & 0x0000FF)
if pdu.arbitration_id.pgn.is_destination_specific and \
pdu.arbitration_id.destination_address != constants.DESTINATION_ADDRESS_GLOBAL:
# send request to send
rts_msg = Message(extended_id=True,
arbitration_id=rts_arbitration_id.can_id,
data=[
constants.CM_MSG_TYPE_RTS,
pdu_length_msb, pdu_length_lsb,
len(messages), 0xFF, pgn_lsb, pgn_middle,
pgn_msb
],
dlc=8)
self.can_bus.send(rts_msg)
else:
rts_arbitration_id.pgn.pdu_specific = constants.DESTINATION_ADDRESS_GLOBAL
bam_msg = Message(extended_id=True,
arbitration_id=rts_arbitration_id.can_id,
data=[
constants.CM_MSG_TYPE_BAM,
pdu_length_msb, pdu_length_lsb,
len(messages), 0xFF, pgn_lsb, pgn_middle,
pgn_msb
],
dlc=8)
# send BAM
self.can_bus.send(bam_msg)
for message in messages:
# send data messages - no flow control, so no need to wait
# for receiving devices to acknowledge
self._long_message_segment_queue.put_nowait(message)
else:
can_message = Message(arbitration_id=msg.arbitration_id.can_id,
extended_id=True,
dlc=len(msg.data),
data=msg.data)
self.can_bus.send(can_message)
