Page 1 of 1

Home moisture sensing

Posted: Thu May 18, 2017 1:37 pm
by steeldemonuk

I am a noob. Sorry about that. Am currently learning the basics of Python and I have a few Rpi's around at home. I'm also building a house. Out of straw.

I have had a pretty reasonable look through all the posts I could see that would relate but I think inexperience in this area is making this complicated for me.

What I will be wanting to do in the not so distant future is to place maybe 10 moisture sensors into the walls of my house - as it will have walls predominantly made of straw this won't be too dificult but what I would really like is some general opinions on how people would collect, store and process the data. My eventual plan would be to have a real-time knowledge of damp areas within the straw but also have a substantial amount of data that I can plot for trend analysis etc.

So - what sensors would you guys use? Would you write your own program in Python (as I am thinking)? What am I completely missing?

I could, of course, go about this using established Windows software I have seen - but I was given 10 Raspi Zero W a few months back and it sounds like a fun project.

Thoughts, if you don't mind, please?


Re: Home moisture sensing

Posted: Sat May 20, 2017 2:57 pm
by lmarmisa
Maybe these sensors could be useful:

1) BME280 ... 66-bme280/

2) DHT22 ... t22-sensor

You could use RPi Zero W or ESP8266 devices as controllers. I recommend to design a MQTT based solution with a Mosquitto MQTT broker running on a RPi.

Re: Home moisture sensing

Posted: Sat May 20, 2017 3:12 pm
by emgi
I'm using two of these in my greenhouse:
They work flawless with joan's pigpio library:


Re: Home moisture sensing

Posted: Mon May 22, 2017 8:35 pm
by Ronaldlees
In industry they often take a piece of the material, weigh it, dry it, and re-weigh it to check the difference and calculate the moisture. That's not very automatic, and the interface to the Pi is not too viable there.

Re: Home moisture sensing

Posted: Mon May 22, 2017 9:07 pm
by steeldemonuk
Hi guys.

Thanks for the info so far. Obviously this is just me testing the water to see what might be possible.

This project would be for a permanent residence (full-size house) and I suppose I was just looking to see if anything clever may be done.

In all honesty it is fair to say that it isn't something that's necessity driven - but I just love the idea of using these pi's....

Re: Home moisture sensing

Posted: Mon May 22, 2017 9:24 pm
by Ronaldlees
I just Googled "straw house" - and it seems I may have been showing my ignorance of some things. I read that the straw is densely packed, so there's not very much "surrounding air". Apparently, the point is to make sure the straw has a low moisture content before it's encased in plaster. Then, theoretically, if no more moisture gets in, there won't be spontaneous combustion. I would think the industry itself (just my short googling revealed there actually is one) - would have some kind of sensor for this purpose, that would be safe, unlike a (potentially) unsafe homemade setup.

Still - this is a very strange concept for me :-)