Bazsi's Home Automation blog

In the past installments of this post series, I was writing about how I, as a software engineer, started troubleshooting the heating system in our new house. This all started by acknowledging there was a problem ( part I ), understanding the basic heating components, such as manifolds ( part II ). Smart thermostats and PID controls ( part III and part IV ). The solution needed in-depth monitoring/debugging so part V was about 7 pieces of DS18B20 sensors and a Raspberry Pi, I've installed in the boiler room. The solution was a bit of a surprise and may I add, I was kind of shocked about the simplicity of the solution once I knew the issue. Remember, that the original reason I started the whole exercise was to make comfortable temperatures in the house, as it was a bit cold. After I've excluded all relevant problems (manifests, water-flow, thermostats, pump, etc), all I had left was to increase the boiler temperature, thereby increase the temperature of the water in the...

In this series of blog posts I am revisiting the process of troubleshooting the heating system in our new house. In the past installments I've described the most important elements of the system (and the ones I fixed), since those didn't reveal the true issue with my heating, I needed to go on. This post is about my monitoring gear. Temperature sensing was a key element of finding the solution. First of all, I have a number of analogue temperature gauges around the boiler/furnace, each attached to a specific section of the system. What I had to learn was that these gauges are very slow to react, and thus were pretty much unusable for my goals. If your temperature has very low volatility, they might be fine, but if you want to understand how and why temperature changes, you will need something that gives you a reading every 10-30 seconds. To address this problem I used a dormant Raspberry Pi and a pair or Onewire sensors I had lying around. These were of the type DS18...

This post is a continuation of my last post about KNX thermostats , which is part of my series about the troubleshooting of our heating system. In the last post I gave a "software sided" intro on our smart thermostats, but I've found the control theory behind these devices even more fascinating. But first of all, let me introduce you to our thermostats: As you can see, there are some leds, a push button and a rotary control labeled from -3 ... +3. The leds indicate the current operating mode (comfort, standby & night mode), as well as frost and heat protection. The rotary control allows the user to customize the temperature in the room: the mid-point is set with KNX parameters and the user may subtract from or add to maximum 3 degrees to that value. I mentioned in the last article that the midpoints were not set to the same value, which could explain some of the temperature differences. I also mentioned that you can set an adjustment to the temperature measu...

As described in the previous incarnations of this series ( part I: introduction , part II: heating manifolds ), the heating in our new house wasn't working very well, and I was working on finding out the root cause, as someone without too much proficiency in mechanical engineering, but with a software engineer background. This installment is about our smart thermostats connected to a KNX (aka EIB) based backbone , that control the valves (turn on/off) on our heating manifolds for per-room temperature control. I described in the previous post, I was suspicious of the thermostats, as some of our rooms were set to the same temperature, and one was warm while the other was cold. These thermostats have a couple of parameters that can be adjusted that would significantly change their behavior. The most important ones from my perspective are the temperature adjustment: to offset to be added/substracted to the measured temperature to counter potential sensor errors the base setpoi...

In the last part of this series , I've outlined the heating system in our newly acquired house, which had some issues: namely it was not warm enough. As a  software engineer I was trying to find the problem by modeling the components in the system, then by coming up with a theory that could be the root cause, then either prove or disprove it by doing measurements. Even if the theory is wrong, I learn something about how the stuff works. If I am right I get closer to solving the problem. The first theory I had was about water flow. I was kind of sure that the boiler produces enough heat, but if the hot water is not flowing through the pipes in sufficient quantities our rooms will remain cold. So I was trying to find how I can find the flow information. The answer lies  in the heating manifolds: I have one of these on all floors of the house, their role is to distribute the incoming hot water into multiple downstream pipes (under the floor heating or wall heating) and...

This story is about my journey as an IT professional into the realms of heating control systems, where I had basically zero experience. I was learning the guts of such a system at my own expense, and today I am confident in changing even major parameters of my pretty complicated setup (for a house anyway). My motivation for writing this story is 1) to document it for myself and 2) to make it useful for those who are fighting similar issues. I am an engineer, but not a mechanical engineer: I had no clue about pumps, valves and control systems. Yet, I was able to decompose and understand what I found and came up with solutions to my problem(s). So here it goes. How it all started We've recently moved into a new house with one nightmare scenario: it's not going to be warm enough. I was telling my wife that this was impossible: just look at the oversized boiler in the basement. 55kW, it's HUGE. No way, we'll have issues with temperature. But at the end she is a...

This was my personal blog that I abandoned ~10 years ago in favor of a corporate blog.  I am reviving it and continue where I left off. This blog has focused a lot on technology and syslog-ng particular and that is something I don't want to change. I work a lot on home automation these days so I expect that to creep in. It's difficult to explain a decade in a blog post but a few items follow that I consider noteworthy: * syslog-ng became pretty successful as a commercial offering while still keeping the open source version in shape. In this 10 years the project produced 23 major syslog-ng releases with lots of new stuff open source first. * Balabit a company has grown to 250+ employees EUR 20m+ revenue and was eventually sold to a US company called Quest/One Identity in 2018 * I left Balabit a year and a half later in 2019, the company behind syslog-ng, the one I was a founder of. syslog-ng is still thriving and is gaining momentum. This is true for both the open so...