openhab/sml

Power Meter with SML

Read data from a power meter (eHZ = Elektronischer Haushaltszähler) using Smart Message Language (SML).

First of all you need is a eHZ (Elektronischer Haushaltszähler) and an IrDA USB dongle like described here. I got mine from Udo (Volkszaehler) some time ago but it looks like he is not directly selling these anymore. What I found is this link to a shop selling the same dongles on Amazon. If your eHZ is not next to your openHAB device you might want to extend the USB cable using a USB over LAN extender, which works pretty good for me.

I used several information from the openHAB community, mainly from this topic.

You need to get, modify and compile libsml (the old libsml is dead!) from Github liked described here and in my comment about the new repository further down in the thread. But I included my version of sml_server.c (pulled and edited 2018/01/19) here as it differs a bit.

If you like to have a fixed device name (e.g. /dev/sml0 instead of /dev/ttyUSB0) which cannot change (it may if you plug in another USB device), please use the 50-sml.rules file and modify it. To find our the serial and maybe also different manufacturer of our device use lsusb -v to display USB device properties.

• 50-sml.rules: Put this file into your /etc/udev/rules.d directory and modify it for your specific setup.
• sml.items: Put this file into your /etc/openhab2/items directory.
• sml.rules: Put this file into your /etc/openhab2/rules directory and modify it for your specific setup. In my case the compiled sml_server is in /home/openhabian/src/libsml/examples. You also might need to adjust the device name, in my case it is: /dev/ttyUSB0
• sml_server.c: Put this file into the libsml subdirectory src/libsml/examples and compile libsml with this file, not the original one.