Oakrey.UDS 2.0.2

Oakrey.UDS

Overview

Oakrey.UDS is a .NET 10 class library implementing the ISO 14229 (UDS) diagnostic protocol. It runs over Oakrey.ISOTP as the transport layer and exposes a fully async, CancellationToken-aware API through the UnifiedDiagnosticServices class. Responses are returned as UdsResponse value types and can be post-processed with a set of chainable extension methods.

Main Features

Implemented UDS services

Response extension pipeline (UdsExtensions)

• ProcessDTCs() � deserialises the DTC payload into List<DiagnosticTroubleCodes>.
• ToAscii() � decodes the response data as ASCII text.
• ToBytes() � returns raw response bytes.
• ToUInt(offset, length) � extracts an unsigned integer from the response data.

Enumerations

• DiagnosticSessionControlType � Default (0x01), Programming (0x02), Extended (0x03), EOL (0x40), Development (0x4F).
• EcuResetType � HardReset (0x01), KeyOffOnReset (0x02).
• StatusOfDtc � bitmask flags for DTC availability and status filtering.

Extensibility

• UdsServiceBase is public and can be subclassed to implement additional UDS services.
• IRequest defines the contract used by UnifiedDiagnosticServices for request dispatch.

Architecture

graph TD
    ISOTP["Oakrey.ISOTP<br>(ISOTPProtocol)"]
    UDS["UnifiedDiagnosticServices<br>(public API)"]
    Base["UdsServiceBase<br>(abstract)"]
    Services["DiagnosticSessionControl<br>EcuReset<br>ClearDtc<br>ReadDataByIdentifier<br>WriteDataByIdentifier<br>ReadDtcInformation<br>SecurityAccess"]
    Response["UdsResponse<br>(value type)"]
    Ext["UdsExtensions<br>(ProcessDTCs, ToAscii,<br>ToBytes, ToUInt)"]

    ISOTP --> UDS
    UDS --> Base
    Base --> Services
    UDS --> Response
    Response --> Ext

Requirements

• .NET 10 or higher
• Oakrey.ISOTP (project reference or matching NuGet package)

Installation

.NET CLI

dotnet add package Oakrey.UDS

Package Manager Console

Install-Package Oakrey.UDS

NuGet Package Manager

1. Open Visual Studio.
2. Go to Tools > NuGet Package Manager > Manage NuGet Packages for Solution.
3. Search for Oakrey.UDS and click Install.

Example Usage

Setup

// Create and configure an ISO-TP protocol instance
ISOTPProtocol isoTp = new ISOTPProtocol();
isoTp.AddService("ECM", rXAddress: 0x7E8, tXAddress: 0x7E0);

// Subscribe CanTX to your CAN bus send method
isoTp.CanTX.Subscribe(msg => canBus.Send(msg.Id, msg.Data));

// Feed received CAN frames into ISO-TP
canBus.OnMessageReceived += (id, data) => isoTp.CanRX(id, data);

UnifiedDiagnosticServices uds = new UnifiedDiagnosticServices(isoTp);

Switch diagnostic session

UdsResponse response = await uds.DiagnosticSessionControl(
    "ECM",
    DiagnosticSessionControlType.Extended,
    CancellationToken.None);

Read data by identifier

string vin = await uds
    .ReadDataByIdentifier("ECM", 0xF190, CancellationToken.None)
    .ToAscii();

Write data by identifier

UdsResponse response = await uds.WriteDataByIdentifier(
    "ECM",
    dataIdentifier: 0x0100,
    data: [0x01, 0x02, 0x03],
    CancellationToken.None);

Read and process DTCs

List<DiagnosticTroubleCodes> dtcs = await uds
    .ReportDiagnosticTroubleCodesByStatusMask("ECM", StatusOfDtc.TestFailed, CancellationToken.None)
    .ProcessDTCs();

foreach (DiagnosticTroubleCodes dtc in dtcs)
{
    Console.WriteLine($"DTC: 0x{dtc.Code:X6}  Status: {dtc.Status}");
}

ECU reset

await uds.EcuReset("ECM", EcuResetType.HardReset, CancellationToken.None);

Extract an integer from a response

uint odometer = await uds
    .ReadDataByIdentifier("ECM", 0xA100, CancellationToken.None)
    .ToUInt(offset: 0, length: 3);

Development Notes

• UnifiedDiagnosticServices uses a single pendingRequest field � only one request can be in-flight at a time per instance. Concurrent use requires separate instances.
• UdsServiceBase silently ignores ResponsePending (0x78) responses and continues waiting, in compliance with the UDS spec.
• SecurityAccess performs the seed/key exchange internally: it requests the seed, computes the key using the Login property, and sends the key reply automatically.
• UdsException.ThrowIfOperationFailed is called by all extension methods � failed responses surface as exceptions in the continuation task.
• Base timeout is 3000 ms; override BaseTimeout in a UdsServiceBase subclass to change it for custom services.

Project Information

• Author: Oakrey
• License: MIT
• Repository: Azure DevOps
• Package URL: nuget.org/packages/Oakrey.UDS

License

This project is licensed under the MIT License. See the LICENSE file for details.