Domotic Project

Question

I’ve planned to develop an application to control connected object, these objects are using the MQTT protocol. The application will be developed in JAVA (with paho library for the MQTT part). I use HiveMQ as a broker with a mysql plugin to store the published values for history purpose. My goal is to create an application which will allow the user to manipulate those connected objects such as turn off a specific light, every lights in a room or in the house, etc … But also to create some routine which will allow automation some actions such as turn on the heat when the temperature is down to 18°C, etc …

But I’m facing some difficulties :

• When I connect with the client application, I would like to load the connected objects to prevent from using the disconnected objects, how to do so ? I thought about create a xml file which will be modified every connection or disconnection of an object. That file will be sent when the client connects.
• How to manage routines (scripts) on the server ?

I’m open to every ideas, suggestions, etc …

Thanks a lot

Answer 1

Couple of suggestions

1. Use the Last Will and Testament and retained messages to alert when objects go offline (http://www.hivemq.com/mqtt-essentials-part-9-last-will-and-testament/)

2. couple of options here:

   • Have a look at using something like node-red (http://nodered.org) to allow users to build "flows" that allow rules/actions to fire based on values.
   • Look at the BSF (https://commons.apache.org/proper/commons-bsf/) to allow users to write scripts