I'm trying to send measurement values to my Cumulocity Tenant via JSON MQTT.
For my test connection I use MQTTBox.
I have already successfully sent data / create new deivces via MQTT.
100,MQTT-Simulation-1,c8y_MQTTdevice
211,80
I have now tried to change my format to JSON MQTT.
According to the Cumulocity IoT Guide (http://www.cumulocity.com/guides/mqtt/json/) I have defined my MQTT topic endpoint.
<api>/<resource>/<action>/<id>
measurement/measurements/create/231
Topic to publish: measurement/measurements/create/231
Payload Type: String / JSON / XML / Characters
Payload: {"c8y_Temperature": {"T": {"unit": "°C","value": 35.742410434759904}}}
As described in the guide, the payload of SmartRest can be used?
The examples in the Guide looks different as described, no ID can be found here in the topic to publish.
A subscription to the topic error is also not possible. Only to the topic smartrest error s/e.
JSON via MQTT will only be possible in the next release for my main tenant - cumulocity support.
Related
Trying to send data to kafka topic from kura through Mqtt proxy but receiving strange values in kafka topic
we are trying to send json data to kafka topic
The MQTT proxy only sends binary data (bytes or strings), and Control Center can only show strings.
You will want to verify the Kafka producer settings to see if it is truly sending JSON, and not other binary format, or compressed/encrypted bytes.
You can further debug with kafka-console-consumer, rather than use any UI tool
I am trying to get weather forecasts data from OpenWeatherMap and integrate them in Orion by performing a registeration request.
I was able to register and get the API key from OpenWeatherMap, however, the latter returns a JSON file with all the data inside, which is not supported by ORION.
I have followed the step by step tutorial https://fiware-tutorials.readthedocs.io/en/latest/context-providers/index.html#context-provider-ngsi-proxy where they have acquired the data from OpenWeatherMap using NGSI proxy, an API key is required to be indicated in the docker-compose file as an environment variable, however, the data acquired is the "current data" and not forecast and also specific to Berlin.
I have tried to access the files inside the container "fiware/tutorials.context-provider" and try to modify and match the parameters to my needs but I feel like I am taking a long blocked path.
I don't think that's even considered as good practice but I have run out of ideas :(
Can anyone suggest how I could bring the forecast data to Orion and register it as a context provider?
Thank you in advance.
I imagine you aim to implement a context provider, able to speak NGSI with Orion.
OpenWeatherMap surely doesn't implement NGSI ...
If you have the data from OpenWeatherMap, as a JSON string, perhaps you should parse the JSON and create your entities using some select key-values from the parsed OpenWeatherMap? Save the entity (entities) locally and then register those keys in Orion.
Alternatively (easier but I wouldn't recommend it), create local entities with the entire OpenWeatherMap data as the value of an attribute of the entity:
{
"id": "id-from-OpenWeatherMap",
"type": "OpenWeatherMap",
"weatherData": {
"value":
...
}
...
}
Then you register id/weatherData in Orion.
I'm trying to do few quick prototypes of using RabbitMQ as message broker for internal services as well as messages from external clients received by gateway over websocket connection.
I decided it would be best (and probabaly only) option for client to publish messages as json, and then for gateway to simply send the unaltered json messages forward.
I've seen that RawRabbit have the ability to take raw Json as message and then deserialize it to C# class.
What I can't find is some example and/or documentation of how the process should look like. Also cannot find documentation of how the Json message should be formatted.
Protocol: A standard to define a method of exchanging data over a network.
If a browser wants to communicate with a server, it has to create an HTTP request and send that HTTP request to the server to convey its request of resources and options. The server receives the request and process it and do the needful and create an HTTP response to send to the browser. The browser has to follow the HTTP specification in creating the HTTP request. The server also has to follow the HTTP specification in creating the HTTP response. This is how the communication between the browser and the server happens in a standard way to avoid conflicts by following the HTTP protocol.
Json Wire Protocol: A client has an object that has to be sent to a server. The client converts this object into a JSON object and sends it to the server. The server parses the JSON object and converts it back to object for use. The server converts the response object into a JSON object and sends it back to the client. The client then converts the JSON object to object for use.
Why the later is called as Json Wire Protocol?
You are pretty correct both about Protocol and JsonWireProtocol. At this point it is worth to mention that, earlier all implementations of WebDriver that communicated with the browser, or a RemoteWebDriver server shall use a common wire protocol. This wire protocol defines a RESTful web service using JSON over HTTP.
JSON Wire Protocol is an abstract specification of how automation behavior like clicking or typing or whatever you actually want to do with your automation script is mapped to selenium or appium or HTTP requests and response. The protocol will assume that the WebDriver API has been "flattened", but there is an expectation that client implementations will take a more Object-Oriented approach, as demonstrated in the existing Java API. The wire protocol is implemented in request/response pairs of "commands" and "responses".
What is JSON Wire protocol?
JSON (JavaScript Object Notation) is a lightweight format for data exchange between client and server. Applications use JSON objects to send and receive data between each other in the web world. JSON data structure is industry standard and can be used for sending and receiving data as Key & Value pair. Some people say its a very nice alternative for XML. We can save JSON files as .json extension.
How JSON looks like?
A simple json file looks like below and there are many online editors which can be used to edit and verify JSON structure.
{
"Student":{
"FirstName":"Pawan",
"LastName":"Garia",
"IdNumber":"12345",
"City" : "New Delhi",
"EmailID" : "email#gmail.com" }
}
Why JSON Wire Protocol was used in first place?
To implement a client-server architecture which can give us the following benefits.
You write test in any programming language.
You can perform or run test on cloud services like SauceLabs, BrowserStack or Selenium Grid setup.
You are not bound to run test only on the local machine.
Different Drivers(FirefoxDriver, ChromeDriver) can be crated for browsers and separate implementation by using the same standards.
So client-server implementation requires a standard set of the specification beforehand so that Server and Client should be in sync with each other in term of what is coming and going on request and response. It’s something like a language of communication with each other. So we need some common specification to solve this kind of requirement and the solution was HTTP.
Why HTTP is the solution?
HTTP is a standard for web and can be a good base for the specification. Every programming language has a good HTTP libraries which can be used for creating client and server for request and response calls.
How JSON Wire protocol worked with HTTP?
HTTP request and response are generally made of GET and POST requests which is out of scope for this discussion.
Current status
From Selenium perspective, JSON Wire Protocol is obsolete now and the WebDriver W3C Living Document is the new implementation.
WebDriver Communication
The WebDriver protocol is organised into commands. Each HTTP request with a method and template defined in the specification represents a single command and hence each command produces a single HTTP response. In response to a command, the remote end will run a series of actions known as remote end steps. These provide the sequences of actions that a remote end takes when it receives a particular command.
Command Processing
The remote end is an HTTP server reading requests from the client and writing responses typically over a TCP socket. In the specification the communication is modeled as the data transmission between a particular local end and remote end with a connection to which the remote end may write bytes and read bytes. The exact details of how this connection works and how it is established is a bigger topic and out of scope for this question. After a connection has been established, the remote end must read bytes from the connection until a complete HTTP request can be constructed from the data. If it is not possible to construct a complete HTTP request, the remote end must either close the connection, return an HTTP response with status code 500, or return an error with error code unknown error.
Outro
Difference between JsonWireProtocol mechanisms and the new standards in W3C Living Document when using Selenium
I try to send data to thingsboard via mqtt. The mqtt node shows connected status but data is not transferring to thingsboard. Eventhough data is in json format, data is not receving in thingsboard. Any help will be more helpful.
sample sending data:
{ "main-door": "closed", "main-light": "OFF"}
You need to follow the Thingsboard rules for payload format at https://thingsboard.io/docs/getting-started-guides/helloworld/#pushing-data-using-mqtt-coap-or-http
You did not say which topic you are publishin to.