#cloudmqtt

mqtt için her geçen yeni bir client, kütüphane yayınlanmaya devam ediyor. bunlardan en kullanışlarından bir tanesi kesinlikle paho . sitesinde an itibariye mqtt için C/C++, Java, Javascript, Python, Go ve C# .NET destekleri olduğu görülmekte. paho nun python kütüphaneleri kullanarak basit bir örnek yapalım. öncelikle gerekli kütüphaleri raspberry üzerine yükleyelim. pi@cicek ~ $ sudo pip install…

We want to store sensor data from Arduino or any other device in a time-series database like TempoDB. TempoDB offers ReST APIs that we could use to write the data series from Arduino directly into TempoDB. But that would be too easy ;)

In fact, we don't want each and every device to directly access the database. Instead, want a more generic solution that leverages the MQTT messaging protocol and the concept of message brokers.

Our Arduino publishes its sensor values already to an MQTT broker.

So how do we get the time series from CloudMQTT (or any other MQTT broker) into TempoDB?

As TempoDB does not provide a native MQTT interface (yet?), we will build a listener that is subscribed to a MQTT broker, and upon receipt of a new message, it simply writes the message into TempoDB.

The listener is based on the Ruby MQTT pub/sub client and the Ruby TempoDB client (clients for other languages are available, too): 

https://gist.github.com/6790192

Deployed to Heroku as a web app:

Clone the listener web app from GitHub to your local machine.

Follow the Getting Started with Ruby on Heroku instructions to install the necessary gems and familiarize yourself with app deployment to Heroku.

Deploy the web.rb app from the cloned Git repository with git push heroku master

Start the app with heroku open

Publish MQTT messages and use TempoDB's console to verify that the values are indeed stored.

Messages containing sensor values that are published to the local MQTT broker (Mosquitto) should also be available for subscription on the remote MQTT broker (CloudMQTT).

       This can be achieved with "bridges", a concept that MQTT servers provide. The bridge between Mosquitto and CloudMQTT can be established as followsSSH into the local server and edit the Mosquitto config file: nano /etc/mosquitto/mosquitto.conf

Add the following lines:

https://gist.github.com/6790584

Restart mosquitto (sudo systemctl restart mosquitto.service)

Test the connection with mosquitto_sub -h broker.cloudmqtt.com -p <port> -u <username> -P <password> -t arduino/temperature

Note: Get port/username/password for CloudMQTT by running the following command in a console: heroku config

To debug, systemctl status mosquitto.service may be helpful.

  References:

Today, we will connect our home network to the outside world, MQTT-style:

Sign up for free on Heroku. Heroku is a cloud-based Platform as a Service (PaaS), which basically means that you can host your own applications in the cloud. 

Create a new app (click "Create new App"). It's free as long as you only use one web dyno.

Add the CloudMQTT add-on (beta). As the name suggests, CloudMQTT is a cloud-based MQTT pub/sub broker, just like Mosquitto. Only in the cloud.

Click on the newly installed add-on within the "Add-ons" section in your Heroku Dashboard. It'll show you the username/password as well as the endpoint and port for the CloudMQTT instance.

You can use these connection details to connect to CloudMQTT and publish/subscribe topics with any MQTT client.