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Kiln temp and humidity logger using the Raspberry Pi platform

Started by btulloh, December 31, 2017, 02:05:44 PM

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btulloh

HM126

Crusarius

btulloh thanks for posting this. that is some really good information. 60 degree ambient = 130 in the kiln. thats pretty crazy!

vfauto

The definition of insanity is to do the same things over and over and expect a different result!

YellowHammer

YellowHammerisms:

Take steps to save steps.

If it won't roll, its not a log; it's still a tree.  Sawmills cut logs, not trees.

Kiln drying wood: When the cookies are burned, they're burned, and you can't fix them.

Sawing is fun for the first couple million boards.

Be smarter than the sawdust

btulloh

Quote from: vfauto on February 28, 2018, 07:32:09 PMAre you going to be selling these loggers?


Not likely.  This is really just a science project.  I doubt there's a market.  
HM126

vfauto

Quote from: btulloh on March 01, 2018, 06:14:17 PM
Quote from: vfauto on February 28, 2018, 07:32:09 PMAre you going to be selling these loggers?


Not likely.  This is really just a science project.  I doubt there's a market.  
I would be interested in one, what is the investment?
The definition of insanity is to do the same things over and over and expect a different result!

btulloh

I don't have a big investment in parts - the big investment is time.  

It's one thing to make something like this for one's own personal use, but it's another thing entirely to make something that other people can use and be satisfied with.  At this point the logger is appropriate for someone who has a background in tech and is willing to nudge it here and there when necessary.  To take it beyond that requires a great deal more work in making the software bullet-proof, providing real robust sensors and appropriate sensor housings, documentation, and most of all SUPPORT.

I could make my software and a parts list available, but it's still a science project and it would only be appropriate for a few people that have a background in this stuff.  I may fab up a few pc boards just to clean up my own wiring and could make these available, which would make the implementation a lot easier and more robust.  In any case, it's a long way from a turn-key system, and the work required to get to that point is significant.
HM126

ChugiakTinkerer

Looking awesome!  I really like how the enclosure box really ties it all together.  Looks pretty to me!

I've been distracted on my project, I need to get an enclosure and a proper shield for the sensor so I can start monitoring weather.  But it's work time at the property so my weather station project is going to have to wait.

I like the Thingspeak page you have set up.  It's all there and easy to see what is going on.

Well done, now time to put it to the real test!
Woodland Mills HM130

btulloh

Good to hear from you CT.  I figured you must've got sidetracked.  Life has a way of interrupting these fun projects.  I was lucky I got the bulk of the work done back in early January when I had a couple weeks of bad weather and a lull in the regular activities.  Since then it's been hard to find any time for this, or sawing, or putting a load in the kiln, or anything else really.  March is the start of yard and field work, plus I've been spending some time on firewood, and now today I have to deposit an hour of precious daylight into the Bank of Daylight Savings.  (I'm looking forward to the time when I can start withdrawing all that daylight I've saved over the years.  I hope it's earned some interest.)

I still haven't had time to get a load of lumber together to put in the kiln.  Just too many other things going on, plus we've only had seven days out of the last forty that were good for solar energy.  Clouds, rain, partly cloudy.  Rain and snow tonight and tomorrow.  It has been interesting to monitor the energy collected, but that's really not the primary mission.

It'll be interesting to see you what you come up with for a proper weather shield.  You've probably looked around at the various ways of doing it.  I skipped over that for now - just getting the ambient temp and rH from WeatherUnderground.  They have a lot of personal weather stations reporting to them, so my local data is coming from someone about a mile from me.  Works for now until I get the shield fabricated and properly located.

Keep us posted on your progress.  By the way, we could all stand some more pictures of your remote property.  Things are a little different up in your neck of the woods than down here in the L48.  At least from what I can see on the Discovery Channel.
HM126

btulloh

HM126

btulloh

I'm attaching the file (.ods - from Libre Office Calc) with the data from the recent run of SYP (which was detailed in another thread).  If anyone needs this in xlsm format let me know.

Load - 350 bf of SYP, fresh sawn from older logs - starting mc was 42% by dry sample method

- Fans only for first couple days.

The humidity sensors I'm using (DHT22) seem to get inaccurate as the run progresses.  The readings just don't make sense.  This is not a huge surprise, but I was hoping these sensors might be ok.  Not so much.  I have temp sensors already installed that can be used for wb readings, but I've never put wicks on them.  Time to do that and check rh readings against a calibrated device.

I'm curious to see what anyone may have to say about this data, even with the suspicious rh readings.  The data in the spreadsheet should be self-explanatory, except for the stuff that isn't.  There are some comments on some of the column headers which may clear up any questions.

edit:( Attaching .xlsx version also)
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btulloh

Very difficult to find the proper wick material or appropriate shoe laces for a wet-bulb. Hardest thing I ever attempted by a long shot. :( :( :( :( :( :(



I see four people have downloaded the data file.  Hopefully they'll have something to say/report/ask/tell/complain.  I'd be curious to know what someone else sees in the data. smiley_beatnik smiley_dark_bulb
HM126

PA_Walnut

Quote from: btulloh on July 16, 2018, 08:48:37 PMVery difficult to find the proper wick material or appropriate shoe laces for a wet-bulb. Hardest thing I ever attempted by a long shot.


Nyle's store has them in 25' rolls. I downloaded your XLS to check it out. The amount of data is great!! I questioned the max temp and time for proper sterilization.
I own my own small piece of the world on an 8 acre plot on the side of a mountain with walnut, hickory, ash and spruce.
LT40HD Wide 35HP Diesel
Peterson Dedicated Wide Slabber
Kubota M62 Tractor/Backhoe
WoodMizer KD250 Kiln
Northland 800 Kiln

btulloh

Thanks for the info .Ordering tomorrow.  Problem solved.

Called 3 big lab supply companies here and got nowhere.  Didn't turn up much on the interweb.  

As for sterilization temps and times, with the solar kiln i get what i get and that's it.  May not be perfect, but it beats doing nothing.  Same with setting the pitch.  Definitely not hot enough for long enough,but it does help somewhat.

Thanks for the feedback.
HM126

btulloh

This is the real-time data display which is updated every 10 seconds.  Not sexy, but useful.  

The WB's are waiting for their real wicks.



  
HM126

PA_Walnut

Quote from: btulloh on July 16, 2018, 11:03:47 PMAs for sterilization temps and times, with the solar kiln i get what i get and that's it.  May not be perfect, but it beats doing nothing.  Same with setting the pitch.  Definitely not hot enough for long enough,but it does help somewhat.


Agreed. Not being a critic, just what I noticed. There's certainly vast differences between personal use and retail, also sterilizing for posterity sake or legit matters like quarantined wood, etc. :)

I love your data-acq system. I need to build one. (Rasp Pi and some assoc parts are sitting in my Amazon cart, awaiting my decision to push CHECKOUT).

I have a little Lenovo i3 that I bought for a specific project that is over, so wondering if that may be prudent, in lieu of the Rasp. Pi.

Although I want/need something asap, not sure if I should add another to-do to The List that keeps going the wrong direction. :-\
I own my own small piece of the world on an 8 acre plot on the side of a mountain with walnut, hickory, ash and spruce.
LT40HD Wide 35HP Diesel
Peterson Dedicated Wide Slabber
Kubota M62 Tractor/Backhoe
WoodMizer KD250 Kiln
Northland 800 Kiln

btulloh

"Agreed. Not being a critic, just what I noticed. There's certainly vast differences between personal use and retail, also sterilizing for posterity sake or legit matters like quarantined wood, etc."

True enough.  I didn't take it as criticism.  It's a lower bar when doing this just for myself.  It does make me appreciate what it takes to do it right for commercial purposes.

Lists are long and only get longer.  I managed to get this done back in January during a stretch of really bad weather.  Now I can just do a little work now and then and it doesn't impact the list too badly.

The Lenovo tablet could work, but it may more difficult to implement the i/o needed and may be challenging in general.  Anything is possible though.  The Pi has been worth the price of admission just for curiousity's sake if nothing else.  It's a pretty amazing little beast and fits the task pretty well.  I'd pull the trigger on that purchase and have it on hand when some free time pops up.  If and when you get into it, you're welcome to my code.  I went a little overboard with this project, but it doesn't have to be a complicated thing just to get a few readings.  It certainly isn't necessary to do all this to operate the solar kiln, but it is nice to keep an eye on things in there.
HM126

PA_Walnut

Quote from: btulloh on July 17, 2018, 09:00:15 AMI'd pull the trigger on that purchase and have it on hand when some free time pops up.  If and when you get into it, you're welcome to my code.  I went a little overboard with this project, but it doesn't have to be a complicated thing just to get a few readings.  It certainly isn't necessary to do all this to operate the solar kiln, but it is nice to keep an eye on things in there.


If it's worth doing, it's worth over-doing! ;)

Information is your friend during drying. It would be nice to input some tables on the ideal and/or max moisture loss per species and make some if/then programming to make alarms and notifications

 It would be great to get a notice via SMS that the kiln load is in jeopardy do to losing x amount more moisture per period than expect. Or, the temperature has raised above the anticipated margin so turning-on fan x at z speed until remedied.  ;D
I own my own small piece of the world on an 8 acre plot on the side of a mountain with walnut, hickory, ash and spruce.
LT40HD Wide 35HP Diesel
Peterson Dedicated Wide Slabber
Kubota M62 Tractor/Backhoe
WoodMizer KD250 Kiln
Northland 800 Kiln

btulloh

It's pretty easy to do all that once you have the basic measurements.  Tracking MC would be nice, but more challenging.  I'm working on that mc reading thing, but it's possible to do it using and existing moisture meter with an interface.  

The data can be uploaded automatically to an IoT server and most of those can implement alarms and send notices any way you want.  I have a little test going with data going up to a server.  It's not displayed very well right now, but it's a glimpse of the possibilities.  

KilnDataTest2 - ThingSpeak IoT



Home page: IoT Analytics - ThingSpeak Internet of Things  (This IoT server doesn't really suit my purpose, but it's a free service.  There are lots of choices out there.)

One big advantage to the Pi is that the environment is designed to let you in and do stuff.  The Lenovo is designed to keep you out.  One of the interesting surprises when I first got the Pi was that the NOOBS distribution of the operating system was pretty much ready to start doing development right out the gate.  IDE, various compilers and interpreters, etc.  installed and ready to go.  Plug in a display and a keyboard and it's a computer.  Ethernet and wifi built in.  Once I got it up and running I converted to headless operation and use a remote desktop.  My kiln is within wifi distance of the house, so the system is on the network.  It's easy to do maintenance or further work while it's in operation in the kiln.
HM126

Crusarius

Quote from: btulloh on July 16, 2018, 08:48:37 PM
Very difficult to find the proper wick material or appropriate shoe laces for a wet-bulb. Hardest thing I ever attempted by a long shot. :( :( :( :( :( :(



I see four people have downloaded the data file.  Hopefully they'll have something to say/report/ask/tell/complain.  I'd be curious to know what someone else sees in the data. smiley_beatnik smiley_dark_bulb
I was one of them and have not had time to compile it yet.

btulloh

Quote from: Crusarius on July 17, 2018, 09:43:03 AMI was one of them and have not had time to compile it yet.


Hey I'm not finding fault.  Just trying to stir the pot a little!  With that new youngin' to keep you busy you've got your hands full I bet!

PAW - Just ordered my wick from Nyle.  Many thanks for that info.  I can work on the math while I'm waiting for it to get here.
HM126

Crusarius

I am still watching this very closely cause I would like to do the same thing. I just scored another real nice walnut tree so I need to start doing something soon. right now my biggest dilemma is storing the lumber. I need to just build a storage area for lumber. 

BTulloh, you ever think of just using resistance for moisture content? I don't know if there are any charts out there showing resistance vs moisture but it would not be hard to generate one. that could also be made a formula in an excel spreadsheet to take a resistance value and automatically calculate MC.

btulloh

The biggest challenge I faced when I started sawing lumber was storage.  Three years later it's still my biggest challenge.  I have quite a few outbuildings and NONE of them are what I need for storing lumber.  I feel your pain.  The good news is it's not too hard to make some level stacks somewhere outside and cover the stacks with a piece of tin.  Air-drying is a good first step to kiln-drying, and as long as you've got a good covered stack in a decent place your lumber will be happy until you get your kiln done.

As to MC measurements by resistance, that's one of the main ways the meters work (there's also capacitance and rf).  The data are readily available for R/mc/species, so there's that.  The challenge to implementation is the extremely high resistance values involved and making that measurement in a harsh environment with changing temps and humidity levels.  That's why good meters cost what they cost.  They are a bargain really.  I'm working along in the background on doing my own, but if I was really serious I'd buy a commercial unit with an interface. 

That being said, you can use the Yellowhammer method of stick-and-rudder, seat-of-the-pants flying and get your lumber dried just fine in the solar kiln with just a moisture meter.  No real need for IFR operation - VFR will get the job done.  But what's the fun in that?  :)
HM126

Crusarius

I live on a 10 acre parcel that is all trees. very moist and on a hill. I really need to take some trees down and make a nice flat area for stacking but I also need to make it drier.

The worst part is how wet the parcel is. I do have some nice spalted maple because of it though.

btulloh

Quote from: Crusarius on July 17, 2018, 10:20:32 AMI do have some nice spalted maple because of it though


Every problem is just an opportunity in disguise.:D
HM126

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