Posts made by tkarlsson

Hello,
I have two more pictures to share.
First my Mysensors node. As I wrote, it was one of my first nodes but it is has been working for at least a year:

Further on, my overview in Domoticz looks like this:

Keep on Mysensing,
Tobias

@korttoma ,
Nice pictures you shared! Looks good.
Now I get a bit reluctant about bringing the camera down there next time...
I have no fancy display and all the DS18B20's are individually wired to the box housing the node..

/Tobias

@mfalkvidd,
Sure I can share some graphs. Unfortunately they are in Swedish though.
This is a graph showing 7 out of 10 temperatures from this node.

The graph is showing about 24 hrs and the wood boiler is fired up in the beginning.
I guess you can see which curve is the smoke gas temp
That one is the first to rise, then the boiler itself, later the sensors in the top-middle-bottom of the first accumulator tank and at last the top-bottom of the second tank. The tanks are connected in series (in the winter).

As I wrote, I also try to calculate charge/discharge power, the accumulated energy in kWh and % in the accumulator tanks as good as I can using my 5 temp sensors. I consider room temp (22degreesC) as my zero kWh level and then I calculate the energy using temperatures and a certain water volume corresponding to each temperature sensor. This is a "kWh graph" from about the same period:

All calculations are made in Domoticz and not in the Mysensor nodes.

I happen to have copies of the sketches at another location so cannot share them at the moment. I am sure they are even a bit outdated by now (definitely pre 2.0).

Perhaps, another day, I will click some photos of my installation. Nothing much to see, really. Part of it is behind a layer of insulation. But it is working great!

/Tobias

Hi @korttoma ,
I am using a MAX6675 to measure the temperature of the smoke. I simply trig a flag at a falling smoke temperature under a certain level while the boiler is still warm. Then I reset it as the smoke temperature reaches a higher temperature again.

It was a bit tricky to combine the example sketches to be able to connect both the DS18B20's and the MAX6675 to the same node, but I finally managed somehow. Perhaps there is still some bug in my sketch making it hard to restart after a power outage, I sometimes have to disconnect/connect the power a couple of times before the nodes starts to work again as intended. In the beginning the temperature sensors could get mixed up after a power outage, but then I implemented some kind of static addressing for the DS18B20's (mentioned somewhere else in this forum) and the mix up stopped.

Tobias

Hello!
About a year ago I found out about Mysensors and it has become kind of a hobby since then.
I ordered some stuff from China and started buildning a gateway and a couple of sensors.

I must say it seemed a bit "too good to be true" in the beginning, being able to build my own sensors and monitor/log them through a computer network. All at a very limited budget. I had my doubts but I gave it a chance.

Now I am deeply impressed and thankful for the work that has been done with Mysensors, it helps me and surely many others to overcome lots of communication barriers and instead focus on "the fun of it".

Now to a description of my little "project".

To heat my house up, since I live in a forest-rich part of Sweden, I use a wood boiler that is connected to accumulator tanks with a total volume of 2000 liters. Hot tap water is produced in a small tank inside one of the accumulator tanks.

With the help of the accumulators, I only have to fire up once a day even if it's -20 degreesC (OK, the boiler has to be refilled with more firewood once at that temperature). In the summer, firing up about once a week is enough to provide hot water for the household.

It takes some hard work to prepare firewood for a whole year (about 20 stacked m^3), but I find it good for the body and I also think I can save some money on it.

Before my little project it happened now and then that I forgot to fire the boiler up when I should have. Sometimes someone else in the house simultaneously had (her) own plans on taking a shower or tapping up a bath for a kid and as I heard the shouting from the 2nd floor I then had to run down to the basement, fire the boiler up and make sure to stay there for at least 30 mins (the time it takes to get hot tap water, worst case). I had sometimes been thinking of putting some temperature sensors on the heating system and maybe placing some fancy display in the kitchen, but somehow I never really liked that plan.

Giving Mysensors a shot, I built myself a gateway and a node and installed some temperature sensors. 5 on the tanks, but also one in the wood boiler. Later I also got a type K thermo element to measure the smoke gas temperature.

I am running Domoticz on a Raspberry Pi and apart from the temperatures I have also learnt some LUA scripting and can now also read the momentary accumulator charge/discharge power (W), accumulated energy (kWh) and energy level as a percentage.

What I find most useful, however, is that I am now getting push messages to my phone when It's about time to fire the boiler up and also when to put in more wood!

Thanks again for Mysensors and keep up the good work!

Best Regards,
Tobias Karlsson