After the initial euphoria related to gaining access to my Vitodens I decided to work on a form of using it to controll the unit in a way accessible to regular uses. I created a html page, which - when placed on RPi or another server - can be used as user interface for controlling Viessman. Please note that all that you find here might be used for the device id 20CB at your sole and only risk. Here are the screenshots:
The whole interface is based on:
Below you can find packages with the codes and programs:
Launching the whole thing should be quite easy. viTalk needs to be copied to a separate directory (in my case /var/vitalk), unpacked and compiled with "make install".
The starting script for viTalk needs to be copied to /etc/init.d, made executable with chmod +x vitalk. The line DAEMON_ARG"-t /dev/vitoir0" needs to be adjusted to the name of your interface. The script can then be launched with ./vitalk start. I also added it to the scripts run on startup with "update-rc.d /etc/init.d/vitalk defaults". In order to check if everything works, you need to launch telnet with "telnet localhost 83". If you are greeted with "Welcome at vitalk, the Vitodens telnet interface..." it means that everything is fine.
The PHP scripts need to be placed in a directory presented by your web server - in my case /var/www. There is nothing to configure here.
The html page with all the subdirectories also needs to be placed in a directory of your web server - in my case /var/www/vito. In file ../js/vitoPHP.js you need to modify lines 9-16 by entering your server's IP etc.
Please be warned. The code presented here is to be used only by those who are able to verify how it works and what id does. Those programs will modify memory of your boiler and might damage it. Use at your own risk after checking the code and understanding what it does.