RepetierMqtt - A simple, easy configurable MQTT client to access your Repetier Server

Introduction

RepetierMqtt is a small and simple MQTT client which leverages the RepetierSharp client to forward information from the Repetier Server API to MQTT. It also provides the possibility to send commands via MQTT to the Repetier Server as well as upload and start gcode files.

Framework support

Currently RepetierMqtt supports .NET Core 3.1, .NET 5 and .NET 6.

Getting started

DISCLAIMER: RepetierMqtt is still in beta. Bugs are to be expected - please help improving RepetierMqtt by submitting issues on GitHub.

The following sections show some examples on how to use the RepetierMqtt client. The examples are not exhaustive. I will try to write a more thourough documentation as soon as possible.

RepetierMqtt uses a fluent builder api to reduce the complexity when creating a new client instance.

Creating a MQTT client instance

The RepetierMqtt client needs an instance of RepetierConnection from RepetierSharp.

RepetierConnection rc = new RepetierConnectionBuilder()
    .WithHost("demo.repetier-server.com", 4006)
    .WithApiKey("7075e377-7472-447a-b77e-86d481995e7b")
    .Build();
rc.Connect();

RepetierMqttClient MqttClient = new RepetierMqttClientBuilder()
    .WithRepetierConnection(rc)
    .WithMqttClientOptions(MqttOptionsProvider.DefaultMqttClientOptions)       
    .WithBaseTopic("RepetierMqtt/Neptune-19")
    .Build();

MqttClient.Connect();

This creates an simple instance with not much functionally other than offering you a MQTT client to publish messages. The provided BaseTopic is put in front of every other provided topic. The MqttClientOption type holds information about the broker, authentication, etc. See MQTTnet for more information.

Payload of published messages

In order to be able to identify the event and command responses, the published messages contain additional information. data contains the event payload or the command response payload.

Command responses example

{
    "callbackId": 42,
    "command": "listModelGroups",
    "data" : {
      "groupNames": [
        "#",
        "My Robot"
      ],
        "ok": true
    }
}

Event payload example

{
    "event": "jobFinished",
    "printer": "Cartesian",
    "data" : {
      "duration": 519,
      "end": 519,
      "lines": 18961,
      "start": 1615393295
    }
}

Adding default topics for events and response messages

To forward events and responses from commands you can add default topics:

RepetierMqttClient MqttClient = new RepetierMqttClientBuilder()
    .WithRepetierConnection(rc)
    .WithMqttClientOptions(MqttOptionsProvider.DefaultMqttClientOptions)       
    .WithBaseTopic("RepetierMqtt/Neptune-19")
    .WithDefaultEventTopic("Event")               // {BaseTopic}/Event[/{printer}]/{event}
    .WithDefaultResponseTopic("Response")         // {BaseTopic}/Response/{command}
    .Build();

MqttClient.Connect();

With this setup all events associated with a printer are published to their own topic RepetierMqtt/Neptune-19/Event/{printer}/{eventName}. Other events are published to RepetierMqtt/Neptune-19/Event/{eventName}.

Commands can be associated with a printer but are published to their own topic without the printer included RepetierMqtt/Neptune-19/Response/{command}.

Defining topics for specific events or command responses

RepetierMqttClient MqttClient = new RepetierMqttClientBuilder()
    .WithRepetierConnection(rc)
    .WithMqttClientOptions(MqttOptionsProvider.DefaultMqttClientOptions)       
    .WithBaseTopic("RepetierMqtt/Neptune-19")
    .WithCommandResponseTopic("startJob", "StartJobTopic")               //{BaseTopic}/StartJobTopic
    .WithPrinterEventTopic("temp", "Cartesian", "CartesianTempValues")   //{BaseTopic}/CartesianTempValues
    .WithEventTopic("temp", "AllTempValues")                             //{BaseTopic}/AllTempValues
    .Build();

MqttClient.Connect();

Line 5 adds a topic where only information about command responses for the command startJob is published: RepetierMqtt/Neptune-19/StartJobTopic. The callbackId can be used to indentify the send command.

Line 6 adds a topic for temps event associated with the printer Cartesian: RepetierMqtt/Neptune-19/CartesianTempValues. Line 7 adds a topic for all temp events: RepetierMqtt/Neptune-19/AllTempValues.

Define topics for executing various repetier commands

RepetierMqttClient MqttClient = new RepetierMqttClientBuilder()
    .WithRepetierConnection(rc)
    .WithMqttClientOptions(MqttOptionsProvider.DefaultMqttClientOptions)       
    .WithBaseTopic("RepetierMqtt/Neptune-19")
    .WithExecuteCommandTopic("Execute")           // {BaseTopic}/Execute          
    .Build();

MqttClient.Connect();

Different from the previous topics, this creates a subscription for the topic RepetierMqtt/Neptune-19/Execute. You are able to send any command to this topic to be executed.

The payload expected needs some additional information beside the actual command:

{
    "command": "startJob",
    "printer": "Cartesian",
    "data" : {
        "id": 6
    }
}

Where data is the actual object to execute the command. It is possible to leave the printer field blank if the command is not associated with a printer.

Define topics with predefined commands

RepetierMqttClient MqttClient = new RepetierMqttClientBuilder()
    .WithRepetierConnection(rc)
    .WithMqttClientOptions(MqttOptionsProvider.DefaultMqttClientOptions)       
    .WithBaseTopic("RepetierMqtt/Neptune-19")
    .WithPredefinedCommand("Action/ListPrinter", ListPrinterCommand.Instance)  // {BaseTopic}/Action/ListPrinter
    .WithPredefinedCommand("Model/Part42/EnqueueAndStart", new CopyModelCommand(42))  // {BaseTopic}/Model/Part42/EnqueueAndStart
    .Build();

MqttClient.Connect();

This (Line 5) creates a subscription for the topic RepetierMqtt/Neptune-19/Action/ListPrinter which executes a static, predefined command. Line 6 creates a subscription for the topic RepetierMqtt/Neptune-19/Model/Part42/EnqueueAndStart which enqueues the specified model into the print queue and starts it when possible.

Define topics to upload (and start) gcode files/jobs

RepetierMqttClient MqttClient = new RepetierMqttClientBuilder()
    .WithRepetierConnection(rc)
    .WithMqttClientOptions(MqttOptionsProvider.DefaultMqttClientOptions)       
    .WithBaseTopic("RepetierMqtt/Neptune-19")
    .WithUploadGCodeTopic("UploadGCode")           // {BaseTopic}/UploadGCode
    .Build();

MqttClient.Connect();

This topic creates a subscription for the topic RepetierMqtt/Neptune-19/UploadGCode, which is used to upload gcode files and print them directly.

The payload expected for this topics looks like this:

{
    "filepath": "/path/to/file.gcode",
    "printer": "Cartesian",
    "autostart": false,
    "group": "#",
    "overwrite": true
}

Note the path for the gcode file needs to be accessible for the MQTT client. This uses the functions from RepetierSharp, which uses the REST-API to upload/start gcode files.

If autostart is true, group and overwrite can be omitted. The gcode file is directly printed if possible or queued in the printing queue. If autostart is false, the gcode file is uploaded to the specified group of the printer. overwrite determines if a existing file with the same name should be replaced.