def test_can_fd():
timing = can.BitTiming(f_clock=80000000,
bitrate=500000,
tseg1=119,
tseg2=40,
sjw=40)
assert timing.f_clock == 80000000
assert timing.bitrate == 500000
assert timing.brp == 1
assert timing.nbt == 160
assert timing.tseg1 == 119
assert timing.tseg2 == 40
assert timing.sjw == 40
assert timing.sample_point == 75
timing = can.BitTiming(f_clock=80000000,
bitrate=2000000,
tseg1=29,
tseg2=10,
sjw=10)
assert timing.f_clock == 80000000
assert timing.bitrate == 2000000
assert timing.brp == 1
assert timing.nbt == 40
assert timing.tseg1 == 29
assert timing.tseg2 == 10
assert timing.sjw == 10
assert timing.sample_point == 75
def test_sja1000():
"""Test some values obtained using other bit timing calculators."""
timing = can.BitTiming(f_clock=8000000,
bitrate=125000,
tseg1=11,
tseg2=4,
sjw=2,
nof_samples=3)
assert timing.f_clock == 8000000
assert timing.bitrate == 125000
assert timing.brp == 4
assert timing.nbt == 16
assert timing.tseg1 == 11
assert timing.tseg2 == 4
assert timing.sjw == 2
assert timing.nof_samples == 3
assert timing.sample_point == 75
assert timing.btr0 == 0x43
assert timing.btr1 == 0xBA
timing = can.BitTiming(f_clock=8000000,
bitrate=500000,
tseg1=13,
tseg2=2,
sjw=1)
assert timing.f_clock == 8000000
assert timing.bitrate == 500000
assert timing.brp == 1
assert timing.nbt == 16
assert timing.tseg1 == 13
assert timing.tseg2 == 2
assert timing.sjw == 1
assert timing.nof_samples == 1
assert timing.sample_point == 87.5
assert timing.btr0 == 0x00
assert timing.btr1 == 0x1C
timing = can.BitTiming(f_clock=8000000,
bitrate=1000000,
tseg1=5,
tseg2=2,
sjw=1)
assert timing.f_clock == 8000000
assert timing.bitrate == 1000000
assert timing.brp == 1
assert timing.nbt == 8
assert timing.tseg1 == 5
assert timing.tseg2 == 2
assert timing.sjw == 1
assert timing.nof_samples == 1
assert timing.sample_point == 75
assert timing.btr0 == 0x00
assert timing.btr1 == 0x14
def test_string_representation():
timing = can.BitTiming(f_clock=8000000,
bitrate=1000000,
tseg1=5,
tseg2=2,
sjw=1)
assert (
str(timing) ==
"1000000 bits/s, sample point: 75.00%, BRP: 1, TSEG1: 5, TSEG2: 2, SJW: 1, BTR: 0014h"
)
def test_from_btr():
timing = can.BitTiming(f_clock=8000000, btr0=0x00, btr1=0x14)
assert timing.bitrate == 1000000
assert timing.brp == 1
assert timing.nbt == 8
assert timing.tseg1 == 5
assert timing.tseg2 == 2
assert timing.sjw == 1
assert timing.sample_point == 75
assert timing.btr0 == 0x00
assert timing.btr1 == 0x14
def test_bus_creation_bittiming(self):
cantact.MockInterface.set_bitrate.reset_mock()
bt = can.BitTiming(tseg1=13, tseg2=2, brp=6, sjw=1)
bus = can.Bus(channel=0,
bustype="cantact",
bit_timing=bt,
_testing=True)
self.assertIsInstance(bus, cantact.CantactBus)
cantact.MockInterface.set_bitrate.assert_not_called()
cantact.MockInterface.set_bit_timing.assert_called()
cantact.MockInterface.set_enabled.assert_called()
cantact.MockInterface.set_monitor.assert_called()
cantact.MockInterface.start.assert_called()
def _create_bus_config(config: Dict[str, Any]) -> typechecking.BusConfig:
"""Validates some config values, performs compatibility mappings and creates specific
structures (e.g. for bit timings).
:param config: The raw config as specified by the user
:return: A config that can be used by a :class:`~can.BusABC`
:raises NotImplementedError: if the ``interface`` is unknown
"""
# substitute None for all values not found
for key in REQUIRED_KEYS:
if key not in config:
config[key] = None
if config["interface"] not in VALID_INTERFACES:
raise CanInterfaceNotImplementedError(
f'Unknown interface type "{config["interface"]}"'
)
if "bitrate" in config:
config["bitrate"] = int(config["bitrate"])
if "fd" in config:
config["fd"] = config["fd"] not in ("0", "False", "false", False)
if "data_bitrate" in config:
config["data_bitrate"] = int(config["data_bitrate"])
# Create bit timing configuration if given
timing_conf = {}
for key in (
"f_clock",
"brp",
"tseg1",
"tseg2",
"sjw",
"nof_samples",
"btr0",
"btr1",
):
if key in config:
timing_conf[key] = int(str(config[key]), base=0)
del config[key]
if timing_conf:
timing_conf["bitrate"] = config["bitrate"]
config["timing"] = can.BitTiming(**timing_conf)
return cast(typechecking.BusConfig, config)
def load_config(
path: Optional[typechecking.AcceptedIOType] = None,
config=None,
context: Optional[str] = None,
) -> typechecking.BusConfig:
"""
Returns a dict with configuration details which is loaded from (in this order):
- config
- can.rc
- Environment variables CAN_INTERFACE, CAN_CHANNEL, CAN_BITRATE
- Config files ``/etc/can.conf`` or ``~/.can`` or ``~/.canrc``
where the latter may add or replace values of the former.
Interface can be any of the strings from ``can.VALID_INTERFACES`` for example:
kvaser, socketcan, pcan, usb2can, ixxat, nican, virtual.
.. note::
The key ``bustype`` is copied to ``interface`` if that one is missing
and does never appear in the result.
:param path:
Optional path to config file.
:param config:
A dict which may set the 'interface', and/or the 'channel', or neither.
It may set other values that are passed through.
:param context:
Extra 'context' pass to config sources. This can be use to section
other than 'default' in the configuration file.
:return:
A config dictionary that should contain 'interface' & 'channel'::
{
'interface': 'python-can backend interface to use',
'channel': 'default channel to use',
# possibly more
}
Note ``None`` will be used if all the options are exhausted without
finding a value.
All unused values are passed from ``config`` over to this.
:raises:
NotImplementedError if the ``interface`` isn't recognized
"""
# start with an empty dict to apply filtering to all sources
given_config = config or {}
config = {}
# use the given dict for default values
config_sources = [
given_config,
can.rc,
lambda _context: load_environment_config( # pylint: disable=unnecessary-lambda
_context),
lambda _context: load_environment_config(),
lambda _context: load_file_config(path, _context),
lambda _context: load_file_config(path),
]
# Slightly complex here to only search for the file config if required
for cfg in config_sources:
if callable(cfg):
cfg = cfg(context)
# remove legacy operator (and copy to interface if not already present)
if "bustype" in cfg:
if "interface" not in cfg or not cfg["interface"]:
cfg["interface"] = cfg["bustype"]
del cfg["bustype"]
# copy all new parameters
for key in cfg:
if key not in config:
config[key] = cfg[key]
# substitute None for all values not found
for key in REQUIRED_KEYS:
if key not in config:
config[key] = None
if config["interface"] not in VALID_INTERFACES:
raise NotImplementedError("Invalid CAN Bus Type - {}".format(
config["interface"]))
if "bitrate" in config:
config["bitrate"] = int(config["bitrate"])
if "fd" in config:
config["fd"] = config["fd"] not in ("0", "False", "false")
if "data_bitrate" in config:
config["data_bitrate"] = int(config["data_bitrate"])
# Create bit timing configuration if given
timing_conf = {}
for key in (
"f_clock",
"brp",
"tseg1",
"tseg2",
"sjw",
"nof_samples",
"btr0",
"btr1",
):
if key in config:
timing_conf[key] = int(config[key], base=0)
del config[key]
if timing_conf:
timing_conf["bitrate"] = config.get("bitrate")
config["timing"] = can.BitTiming(**timing_conf)
can.log.debug("can config: {}".format(config))
return config