Welcome to pyneovi’s documentation!

Overview

pyneovi is a Python wrapper around the API provided by Intrepid Control Systems for communicating with their NeoVI range of devices.

There are three layers to pyneovi and application code can be written against any of them:

  • API wrapper layer. This is a Python wrapper around the API provided by ICS in their DLL/shared object. Code written against this will primarily use the neovi module, which contains the function wrappers and associated constants. Additionally, some constants are defined in the can module and structures are defined in the structures module.
  • neoVI device layer. This provides a more Pythonic implementation of the API based around objects representing neoVI devices. Code written against this will primarily use the neodevice module.
  • ECU layer. This shifts the focus to the devices being interacted with, providing objects representing ECUs on the network. Code written against this will primarily use the neoVI device layer to set up the interface plus the neodevice module.

The API wrapper layer and the neoVI device layer may both be used as provided. The ECU layer, however, requires additional information about the ECUs being communicated with. This may be provided by the application code directly, but it will usually be preferable to construct a “vehicle spec” file. This describes the networks provided by the vehicle, the ECUs on those networks, and the signals made available by the ECUs. ECUs and signals may then be identified by their names rather than addresses and conversion of the values read from the ECU will be performed automatically. The spec module is used to create a vehicle spec.

Examples

Examples

Submodules

neovi.can module

neovi.ecu module

neovi.neodevice module

neovi.neovi module

neovi.spec module

This module provides classes and functions to allow a network specification to be created for use with pyneovi. A network specification defines the valid networks for a given model of vehicle, along with the ECUs on those networks and the identifiers and signals made available by the ECUs.

Below is an example of a simple network specification. Only the medium speed CAN bus is defined and only a single ECU is associated with that network. The ECU provides four identifiers, each made up of a single signal.

from neovi.spec import *
from neovi.neovi import NETID_MSCAN, BitRate
import json


networks = {NETID_MSCAN: {'bitrate': BitRate.BR_125000}}

hvac_ecu = ECU(NETID_MSCAN, 0x456, 'HVAC')

hvac_identifiers = [
    Identifier('Blower Speed Output',          0x9601, [Signal(units='%', m=100./255.)], READ_WRITE),
    Identifier('External Ambient Temperature', 0x9628, [Signal(units='Deg C', m=0.25)], READ_WRITE),
    Identifier('Left Solar Radiation Sensor',  0x9734, [Signal(units='W', m=10, max_val=1250)]),
    Identifier('Cabin Temperature',            0x97A5, [Signal(units='Deg C', length=16, m=0.01, b=-100, min_val=-50, max_val=100)]),
]


ECUs = {
    'HVAC': {'ecu': hvac_ecu, 'identifiers': hvac_identifiers}
}


output_file = open('vehicle.spec', 'wt')
json.dump({'networks': networks, 'ECUs': ECUs}, output_file, cls=PyNeoViJSONEncoder)
output_file.close()
exception neovi.spec.NonByteBoundarySignalError

Bases: exceptions.Exception

exception neovi.spec.ValueTooLargeError

Bases: exceptions.Exception

exception neovi.spec.UnsupportedValueTypeError

Bases: exceptions.Exception

neovi.spec.prepend_zeroes(values, final_length)
class neovi.spec.Signal(self, name='value', signal_type=ANALOG, value_type=UNSIGNED_INT, start=0, length=8, min=None, max=None, units='', m=1, b=0, description='')

Represents a signal. An spec.Identifier will contain one or more signals.

Parameters:
  • name (str) – The name of this signal.
  • signal_type (int) – The type of signal. Currently, only spec.ANALOG is supported.
  • value_type (int) – The type of value returned for the signal. Currently only spec.UNSIGNED_INT is supported.
  • start (int) – The bit within the identifier’s aggregate value at which this signal starts.
  • length (int) – The length in bits of this signal.
  • min_val (float) – The minimum value for this signal. This is not enforced and is for reference only. If not specified then b is used as the default value.
  • max_val (float) – The minimum value for this signal. This is not enforced and is for reference only. If not specified then (255. * m) + b is used as the default value.
  • units (str) – The units of the signal once converted.
  • m (float) – The slope for conversion of the signal into engineering units.
  • b (float) – The offset for conversion of the signal into engineering units.
  • description (str) – A human-readable description of the signal.
Raises:

NonByteBoundarySignalError – If length or start are not integer multiples of 8.
decode_signal_bytes(signal_bytes)

Converts the individual data bytes into the final value for the signal.

Parameters:signal_bytes (list of ints) – The bytes received from the ECU.
Returns:Tuple of final value and the units of the signal.
Raises:UnsupportedValueTypeError – If the signal is of a type that is currently unsupported.
encode_value(value)

Converts a value into the individual data bytes required for transmission.

Parameters:

value (float/int) – The value for conversion.
Raises:
class neovi.spec.Identifier(self, name, data_id, signals = [], io_type = READ)

Represents an identifier (an example of which would be “Blower Speed Output” in a HVAC ECU). The value of an identifier can consist of multiple individual signals but often there is only a single signal associated with an identifier.

Parameters:
  • name (str) – The name of the identifier.
  • data_id (int) – The address (internal to the ECU) with which this identifier is associated.
  • signals (list of spec.Signal) – The signals that form this identifier.
  • io_type (int) – Allowed IO for this identifier: spec.READ, spec.WRITE, spec.READ_WRITE.
get_data_id_bytes()
Returns:The data_id as individual bytes. Used when constructing a message.
class neovi.spec.ECU(network, address, short_desc='', long_desc='')

Represents an ECU for the purpose of building a network specification. Note that if you need an object that allows you to communicate with the ECU then you’re looking for ecu.ECU.

Parameters:
  • network (int) – The network to transmit on. See NETID_* in neovi.
  • address (int) – The address of the ECU.
  • short_desc (str) – A short name for the ECU (e.g. “HVAC”).
  • long_desc (str) – A long description for the ECU (e.g. including model number or other information).
get_network()
get_request_id()
get_response_id()
class neovi.spec.PyNeoViJSONEncoder(skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, sort_keys=False, indent=None, separators=None, encoding='utf-8', default=None)

Bases: json.encoder.JSONEncoder

Can be passed to json.dump as the cls parameter to handle the additional object types defined here.

default(o)
neovi.spec.from_json(json_object)

Can be passed to json.load as the object_hook parameter to handle the additional object types defined here.

neovi.structures module

Classes provided by this module:
neovi.structures.array_equal(a1, a2)
neovi.structures.format_array(array)
neovi.structures.get_status_bits_set(msg)
class neovi.structures.NeoDevice

Bases: _ctypes.Structure

DeviceType

Structure/Union member

Handle

Structure/Union member

MaxAllowedClients

Structure/Union member

NumberOfClients

Structure/Union member

SerialNumber

Structure/Union member

class neovi.structures.icsSpyMessage

Bases: _ctypes.Structure

AckBytes

Structure/Union member

ArbIDOrHeader

Structure/Union member

ColorID

Structure/Union member

Data

Structure/Union member

DescriptionID

Structure/Union member

MessagePieceID

Structure/Union member

MiscData

Structure/Union member

NetworkID

Structure/Union member

NodeID

Structure/Union member

NumberBytesData

Structure/Union member

NumberBytesHeader

Structure/Union member

Protocol

Structure/Union member

StatusBitField

Structure/Union member

StatusBitField2

Structure/Union member

TimeHardware

Structure/Union member

TimeHardware2

Structure/Union member

TimeStampHardwareID

Structure/Union member

TimeStampSystemID

Structure/Union member

TimeSystem

Structure/Union member

TimeSystem2

Structure/Union member

Value

Structure/Union member

class neovi.structures.spyFilterLong

Bases: _ctypes.Structure

ByteDataLSB

Structure/Union member

ByteDataLength

Structure/Union member

ByteDataMSB

Structure/Union member

ByteDataMaskLSB

Structure/Union member

ByteDataMaskMSB

Structure/Union member

ExpectedLength

Structure/Union member

FrameMaster

Structure/Union member

Header

Structure/Union member

HeaderLength

Structure/Union member

HeaderMask

Structure/Union member

MiscData

Structure/Union member

MiscDataMask

Structure/Union member

NetworkID

Structure/Union member

NodeID

Structure/Union member

Status2Mask

Structure/Union member

Status2Value

Structure/Union member

StatusMask

Structure/Union member

StatusValue

Structure/Union member

bStuff2

Structure/Union member

bUseArbIdRangeFilter

Structure/Union member

class neovi.structures.CAN_SETTINGS

Bases: _ctypes.Structure

BRP

Structure/Union member

Baudrate

Structure/Union member

Mode

Structure/Union member

NetworkType

Structure/Union member

SetBaudrate

Structure/Union member

TqProp

Structure/Union member

TqSeg1

Structure/Union member

TqSeg2

Structure/Union member

TqSync

Structure/Union member

auto_baud

Structure/Union member

class neovi.structures.SWCAN_SETTINGS

Bases: _ctypes.Structure

BRP

Structure/Union member

Baudrate

Structure/Union member

Mode

Structure/Union member

NetworkType

Structure/Union member

SetBaudrate

Structure/Union member

TqProp

Structure/Union member

TqSeg1

Structure/Union member

TqSeg2

Structure/Union member

TqSync

Structure/Union member

auto_baud

Structure/Union member

high_speed_auto_switch

Structure/Union member

class neovi.structures.LIN_SETTINGS

Bases: _ctypes.Structure

Baudrate

Structure/Union member

MasterResistor

Structure/Union member

Mode

Structure/Union member

brgh

Structure/Union member

spbrg

Structure/Union member

class neovi.structures.ISO9141_KEYWORD2000__INIT_STEP

Bases: _ctypes.Structure

k

Structure/Union member

l

Structure/Union member

time_500us

Structure/Union member

class neovi.structures.ISO9141_KEYWORD2000_SETTINGS

Bases: _ctypes.Structure

Baudrate

Structure/Union member

brgh

Structure/Union member

chksum_enabled

Structure/Union member

init_step_count

Structure/Union member

init_steps

Structure/Union member

p2_500us

Structure/Union member

p3_500us

Structure/Union member

p4_500us

Structure/Union member

spbrg

Structure/Union member

class neovi.structures.UART_SETTINGS

Bases: _ctypes.Structure

Baudrate

Structure/Union member

bOptions

Structure/Union member

brgh

Structure/Union member

flow_control

Structure/Union member

parity

Structure/Union member

reserved_1

Structure/Union member

spbrg

Structure/Union member

stop_bits

Structure/Union member

class neovi.structures.STextAPISettings

Bases: _ctypes.Structure

Reserved0

Structure/Union member

Reserved1

Structure/Union member

Reserved2

Structure/Union member

Reserved3

Structure/Union member

Reserved4

Structure/Union member

can1_options

Structure/Union member

can1_rx_id

Structure/Union member

can1_tx_id

Structure/Union member

can2_options

Structure/Union member

can2_rx_id

Structure/Union member

can2_tx_id

Structure/Union member

can3_options

Structure/Union member

can3_rx_id3

Structure/Union member

can3_tx_id3

Structure/Union member

can4_options

Structure/Union member

can4_rx_id4

Structure/Union member

can4_tx_id4

Structure/Union member

network_enables

Structure/Union member

class neovi.structures.SFireSettings

Bases: _ctypes.Structure

ain_sample_period

Structure/Union member

ain_threshold

Structure/Union member

can1

Structure/Union member

can2

Structure/Union member

can3

Structure/Union member

can4

Structure/Union member

cgi_baud

Structure/Union member

cgi_chksum_enable

Structure/Union member

cgi_enable_reserved

Structure/Union member

cgi_rx_ifs_bit_times

Structure/Union member

cgi_tx_ifs_bit_times

Structure/Union member

fast_init_network_enables_1

Structure/Union member

fast_init_network_enables_2

Structure/Union member

iso15765_separation_time_offset

Structure/Union member

iso9141_kwp_enable_reserved

Structure/Union member

iso9141_kwp_settings

Structure/Union member

iso9141_kwp_settings2

Structure/Union member

iso9141_kwp_settings_3

Structure/Union member

iso9141_kwp_settings_4

Structure/Union member

iso_msg_termination

Structure/Union member

iso_msg_termination_2

Structure/Union member

iso_msg_termination_3

Structure/Union member

iso_msg_termination_4

Structure/Union member

iso_parity

Structure/Union member

iso_parity_2

Structure/Union member

iso_parity_3

Structure/Union member

iso_parity_4

Structure/Union member

iso_tester_pullup_enable

Structure/Union member

lin1

Structure/Union member

lin2

Structure/Union member

lin3

Structure/Union member

lin4

Structure/Union member

lsftcan

Structure/Union member

misc_io_analog_enable

Structure/Union member

misc_io_initial_ddr

Structure/Union member

misc_io_initial_latch

Structure/Union member

misc_io_on_report_events

Structure/Union member

misc_io_report_period

Structure/Union member

network_enabled_on_boot

Structure/Union member

network_enables

Structure/Union member

network_enables_2

Structure/Union member

perf_en

Structure/Union member

pwm_man_timeout

Structure/Union member

pwr_man_enable

Structure/Union member

swcan

Structure/Union member

text_api

Structure/Union member

uart

Structure/Union member

uart2

Structure/Union member

class neovi.structures.SVCAN3Settings

Bases: _ctypes.Structure

can1

Structure/Union member

can2

Structure/Union member

iso15765_separation_time_offset

Structure/Union member

misc_io_initial_ddr

Structure/Union member

misc_io_initial_latch

Structure/Union member

misc_io_on_report_events

Structure/Union member

misc_io_report_period

Structure/Union member

network_enabled_on_boot

Structure/Union member

network_enables

Structure/Union member

perf_en

Structure/Union member

class neovi.structures.APIFirmwareInfo

Bases: _ctypes.Structure

iAppMajor

Structure/Union member

iAppMinor

Structure/Union member

iBoardRevMajor

Structure/Union member

iBoardRevMinor

Structure/Union member

iBootLoaderVersionMajor

Structure/Union member

iBootLoaderVersionMinor

Structure/Union member

iMainFirmChkSum

Structure/Union member

iMainFirmDateDay

Structure/Union member

iMainFirmDateHour

Structure/Union member

iMainFirmDateMin

Structure/Union member

iMainFirmDateMonth

Structure/Union member

iMainFirmDateSecond

Structure/Union member

iMainFirmDateYear

Structure/Union member

iManufactureDay

Structure/Union member

iManufactureMonth

Structure/Union member

iManufactureYear

Structure/Union member

iType

Structure/Union member

Indices and tables