obd library

ISO-TP (ISO 15765-2), OBD-II (SAE J1979) and UDS (ISO 14229) clients that run on top of any CanBus, plus a simulated ECU for tests and demos.

Reading is always allowed. Services that change vehicle or ECU state (OBD mode 04, UDS session control, write DID, clear DTCs, security access) need an explicit allowWrites: true.

import 'package:can_bus_toolkit/obd.dart';

final obd = ObdClient(bus);
print((await obd.readPid(0x0C)).first); // Engine speed: 1726 rpm
print((await obd.readVin()).first);

Classes

Dtc

A two-byte OBD-II (SAE J2012) diagnostic trouble code.

IsoTpChannel

An ISO 15765-2 (ISO-TP) connection between two CAN IDs on any CanBus.

IsoTpOptions

ISO 15765-2 transport settings.

ObdClient

OBD-II (SAE J1979 / ISO 15765-4) client on any CanBus.

ObdDetection

Result of ObdClient.autoDetect.

ObdEcuResponses<T>

Responses to one OBD-II request, keyed by the responding CAN ID (for example 0x7E8 for the engine ECU in 11-bit addressing).

ObdEcuSimulator

A simulated ECU that answers OBD-II and UDS requests on any CanBus, for tests and demos without hardware. Usually run on a VirtualCanNetwork bus.

ObdPidDefinition

Definition of a mode 01 / 02 parameter (SAE J1979).

ObdPids

Decoders for common mode 01 / 02 PIDs.

ObdPidSample

One sample from ObdClient.poll.

ObdPidValue

A decoded (or raw) OBD-II parameter.

UdsClient

UDS (ISO 14229-1) client over ISO-TP with physical addressing.

UdsDtc

A DTC reported by UDS service 0x19: 3-byte code plus ISO 14229 status byte.

UdsDtcCount

Response to reportNumberOfDTCByStatusMask (0x19 0x01).

Enums

DtcSystem

Diagnostic trouble code system, from the two top bits of the code.

IsoTpPadding

Whether ISO-TP frames are padded to 8 bytes.

ObdAddressing

OBD-II addressing on CAN (ISO 15765-4).

UdsSession

UDS diagnostic sessions (service 0x10).

Functions

udsNrcName(int nrc) → String

Readable name of a UDS negative response code (ISO 14229-1 Annex A).

Typedefs

SeedKeyFunction = Future<Uint8List> Function(Uint8List seed, int level)

Computes a security access key from an ECU seed. The algorithm is OEM-specific and not part of this package.

SimulatorKeyFunction = Uint8List Function(Uint8List seed, int level)

Computes the key the simulator expects for a security access seed.

Exceptions / Errors

CanWriteNotAllowedException

A request that changes vehicle or ECU state was made without allowWrites: true.

IsoTpException

An ISO-TP protocol error: unexpected sequence number, overflow reported by the receiver, or a malformed flow control frame.

ObdException

An OBD-II request failed or returned data that cannot be decoded.

UdsNegativeResponseException

A UDS (ISO 14229) negative response 7F <service> <NRC>.