Recently I had a look at a Hargassner wood chip boiler, and what kind of free software can be used to monitor and control it. The boiler can be connected to some cloud service via what the producer call an Internet Gateway, which seem to be a computer connecting to the boiler and passing the information gathered to the cloud. I discovered the boiler controller got an IP address on the local network and listen on TCP port 23 to provide status information as a text line of numbers. It also provide a HTTP server listening on port 80, but I have not yet figured out what it can do beside return an error code.
If I am to believe various free software implementations talking to such boiler, the interpretation of the line of numbers differ between type of boiler and software version on the boiler. By comparing the list of numbers on the front panel of the boiler with the numbers returned via TCP, I have been able to figure out several of the numbers, but there are a lot left to understand. I've located several temperature measurements and hours running values, as well as oxygen measurements and counters.
I decided to write a simple parser in Python for the values I figured out so far, and a simple MQTT injector publishing both the interpreted and the unknown values on a MQTT bus to make collecting and graphing simpler. The end result is available from the hargassner2mqtt project page on gitlab. I very much welcome patches extending the parser to understand more values, boiler types and software versions. I do not really expect very few free software developers got their hands on such unit to experiment, but it would be fun if others too find this project useful.As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
