Monthly Archives: August 2013

openHAB EZControl Integration

For quite a time, I monitored the openHAB project. Eventually, I found some time to test it out and tried to set up some of my existing home automation hardware with openHAB.

Therefore, I decided to set up my EZControl XS1 as a very first testbed.

Learning it the Hard Way

Before digging into the details, I’d like to share some of my experience during my very first hours with openHAB.

First of all, the contributors (currently counting 38) have done a great job in documenting the project. Installation and configuration does work quite well. The same for the basic setup of the development environment (e.g. in the case you want to implement an own binding).

Unfortunately, there are many details you need to know to get the system up and running, not being offered at a glance. You have to dig into groups, the wiki, demo files and perform a lot of trying, experience a lot of frustrating errors. Once you figured out how it works, it is not hard to remember. Done once, some of the issues are that simple, that it is clear why they are not mentioned in the wiki at all. Unfortunately, if you haven’t dealt with openHAB before, you have to learn it the hard way.

Not to forget, here’s a list of sources you definitely need to check in case you stuck with your very first setup:

Definitely, do not miss the last one. Many of your questions will be answered in the examples wiki, though. Still, some details might be missing, but that’s the place to check first.

Said that, there’s no critics about the documentation. It’s great, you just see it’s written by those who implemented it. And as such, one sometimes forgets about the trivial bits and bytes one need to know to start.

Setting up the EZControl XS1

Most devices I run on my EZControl are sensors from the ELV FHZ 1×00 System and intertechno wireless receivers.

For my convenience, I uploaded the configuration app to my internal web server though.

XS1 Setup

For now, I am only interested in the sensors available at the sensors tab.

Sensors

Iwanted to be independent from the data structure to set up the XS1 with openHAB. Therefore, the only thing you need to know, is how you named the sensors, though.

Switches

Before starting, make sure the HTTP binding is installed as it is used both, for switches as well as for sensors.

To address switches, you can use the REST interface of the XS and address the switches directly, you simply need to know the number of the switch being used within the query parameters such as number=2 within your *.items configuration file..

Switch Switch_Balcony_gBalcony "Balkon" (gBalcony) {http=">[ON:GET:http://192.168.0.242/control?cmd=set_state_actuator&number=2&function=1] >[OFF:GET:http://192.168.0.242/control?cmd=set_state_actuator&number=2&function=2]" }

Sensors

Sensors can be fetched from the ES1 using HTTP binding as well. Therefore, I pick up the XML output from the ESZ, in my case provided at http://192.168.0.242/xml.

XS1 XML

To pick a corresponding value of a sensor, I’ve created a XSL transformation

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
    <xsl:output indent="yes" method="xml" encoding="UTF-8" omit-xml-declaration="yes"/>
    <xsl:template match="/">
        <xsl:value-of select="xml/data/*[text()='Arbeitszimmer_Temp']/following-sibling::node()"/>
    </xsl:template>
</xsl:stylesheet>

The XSL is quite simple, picking up he value from the next node after the node with the given sensor name. That way, structural changes in the XS1 setup or even a replacement of a sensor do not affect the openHAB configuration.

Create a XSL for each sensor value, you plan to use within openHAB and place them into the transform folder under configurations in the openHAB folder structure.

XSLT Transformations

Again in the *.items configuration file, using the HTTP binding, I pick up the XML for each node and apply the transformation provided, resulting in a single value.

Number Temp_gOffice "Temperatur [%.1f °C]" (gOffice) { http="%lt;[http://192.168.0.242/xml:10000:XSLT(Arbeitszimmer_Temp.xsl)]"}
Number Hum_gOffice "Feuchtigkeit [%.1f %%]" (gOffice) { http="<[http://192.168.0.242/xml:10000:XSLT(Arbeitszimmer_Hum.xsl)]"}

While this works quite well, the XML is fetched from the XS1 for each value node. Looking forward for version 1.3 of openHAB, there is planned to provide a cache, so the XML would be fetched only once while the binding would fetch the data from the cache.

Sensor Values using the HTTP Binding

Done once, adding new sensors or switched using the XS1 takes just a few minutes. Changing the .*items configuration by adding new HTP bindings, copying and modifying the XSLT and adding of course adding the sensors and switches to the XS1.

SOAP with Python

To evaluate a SOAP service, I decided to increase my Python skills by one by consuming the SOAP service with Python. SOAP Web Services from Dive Into Python seemed a quite good starting point with detailed instructions for setting up your Python environment to do so.

After starting to work thought this article how to install the required SOAP libraries, I realized quickly links are broken and various information became obsolete.  Therefore, I decided to summarize the amendments to set up SOAP libraries for Python, in this article focusing on how to set up PyXML, fpconst and SOAPpy.

Prerequisites
Before starting lets be sure Python is installed. You might check with

where python

to determine which python will be accessed via the PATH variable.In my case it is a Python 2.7 running on Windows 8.0.

Python 2.7 on Windows 8.0PyXML
PyXML can’t be accessed via http://pyxml.sourceforge.net/. Instead you have to access the site via http://pyxml.sourceforge.net/topics/ directly. Unfortunately, you might realize that the latest supported version from there is Python 2.4. You will find a Windows Installer for PyXML 0.8.4 for Python 2.7 at the OddThinking blog instead.

Run through the installer, just make sure, you pick the right Python installation during the process.

PyXML Installation DialogVerifying the installation is quite simple using the Python console, though.

>>> import xml
>>> xml.__version__
'0.8.4'
>>

fpconst
Instead of picking up the fpconst package from Unversity of Washington’s broken link,  you’ll meanwhile find fpconst 0.7.2 within the Python Package Index. Download and extract the archive to any temporary folder. Change folders to the extracted one and run

python setup.py install

from the console.

fpconst Package installationAgain very the installed package with

>>> import fpconst
>>> fpconst.__version__
'0.7.2'
>>>

SOAPpy
SOAPpy is probably the package causing the most headache. I first picked SOAPpy 0.12.0_rc1 from the download section at  http://pywebsvcs.sourceforge.net/. It caused more or less trouble, trying to install the package. In addition, SOAPpy was announced to be merged into the ZSI (Zolera SOAP Infrastructure) web service toolkit. If you are going to try ZSI anyway, download and installation are similar to the example above using

python setup.py install

Even the latest version of ZSI installs fine with Python 2.7.

Anyway, when sticking with SOAPpy, you might want to get the latest version (0.12.5) from the Python Package Index. Extracting the archive and following the steps above will result in an import error, though.

Traceback (most recent call last):
  File "setup.py", line 7, in <module>
    from setuptools import setup, find_packages
ImportError: No module named setuptools

To solve this, navigate to the setuptoools 0.9.8 in the Python Package Index, and download ez_setup.py to your local machine. Run the script with

python ez_setup.py

which will compile quite a bunch of stuff on your local machine. Follow the instructions, and add the C:\Python27\Scripts to your PATH variable.

Once installation is complete, you will find an easy_install.exe program in your Python Scripts subdirectory. For simple invocation and best results, add this directory to your PATH environment variable, if it is not already present.

Head back to the download folder of SOAPpy 0.12.5 and run once again

python setup.py. install

which should finally end up in something similar to

...

Installed c:\python27\lib\site-packages\docutils-0.11-py2.7.egg
Searching for fpconst==0.7.2
Best match: fpconst 0.7.2
Adding fpconst 0.7.2 to easy-install.pth file

Using c:\python27\lib\site-packages
Finished processing dependencies for SOAPpy==0.12.5

For the very last time, verify the installation by

>>> import SOAPpy
>>> SOAPpy.__version__
'0.12.5'
>>>

By now, you should be ready to use all three packages with your Python 2.7 installation.

Coll Stuff #2

Some more stuff I came along the last few days…