Home thermometer project - Raspberry Pi-based

[realdocBBQ]

So this has been a bit more than I expected, I've gone down a few rabbit holes, changed my hosting service, etc. Started with Initial State, didn't like their interface, ChatGPT suggested I try Grafana, so now I am on that and using InfluxDB for my data collection.

Started with wanting to do fridge/freezer monitoring in the garage, with alarms and such. Looking on Amazon, there are some cheap ones, but mostly 1 or 2 probes and didn't like the options, the expansion capability and the reviews with a lot of them. Looked at the options from Fireboard and Thermoworks, and they aren't cheap, and still didn't have as many options as I wanted - then I realized I've got several Raspberry Pi computing units laying around and knew these would be perfect.

This led me down the hole of buying a 3D printer (yeah, I'm saving oodles on this project!), but it was used and after a few days of messing around with it, I got it running ok and printed this case for my Raspberry Pi.



It's much taller than I need - but the idea was to have room to wire in some additional chips for sensors, maybe have the ability to add a fan, etc. Also I liked the additional holes in the case for cooling and also for adding 'pigtails' which is my idea for the sensors....

I ordered a bunch of ds18b20 sensors from Amazon. These have a 3-wire connection and can all be wired together to the Pi, as many as I want to run. Like literally, I've seen reports from 64 up to a zillion. Anyways, I currently have 5 pigtails wired up.

I wanted quick connect/disconnect capabilities, so I also ordered mail and female 1/8" headphone jacks, which also had 3-wire connection. Then it was just a matter of soldering all these teeny... tiny... annoying little wires together. Sheesh!






I tell ya, my eyes ain't what they used to be. Damn.

Anyways, got 'em all wired up and with the help of ChatGPT I started working on code.

My plan was to use a free account with Initial State to receive and display my results, but after messing around with it, I didn't like the way it handled the interface tiles and I didn't like the options, etc. So I switched to Grafana and InfluxDB, also both free. I have about 5 million datapoints per month I can log with InfluxDB, so I shouldn't have a problem with that.

Currently running 4 sensors because my 5th was erroring out - I knew I had one probe with a 'sketchy' soldering job, and I'm sure that's what it was... I'll fix that up eventually. I might add some more sensors as well. Who knows, only so much I can monitor in the 3 coolers in the garage, but I could go with 2 probes per compartment, maybe, I dunno.

Here's what it looks like right now.



I need to use my Fireboard with it's thermistor probes to check the accuracy, and I can always program in some offsets if they're not as accurate as I'd like. You can see, my side-by-side fridge temp looks a bit high, so I need to move that probe around a bit and get some more readings. I think I'm actually going to print some little holders for those ds18b20 probes to sit in to make them easier to move around and stand up off the shelves, keep them away from walls, etc., Now that I have it up and running, I can tweak the code and interface and add more features like logging and such.

It is currently able to reboot itself in the case of a power failure, and automatically restarts the script and starts sending data again.

This is a link I think will be permanent, so any of you schmucks can monitor my fridge and freezer temps anytime you want. lol

Lemme know what you think. I'm going to add some additional color coding rules to make the temp display colors more appropriately for quick looks, etc., just need to have time to play with the Grafana interface and learn all the tricks it can do, but I know it can do that.

Here's the link:

https://realdocbbq.grafana.net/public-dashboards/1d429fd6ab9744a5951163b6412c1f2c

I'll add some more pics of the unit itself, it's not completely buttoned up and cleaned up yet, also ordered some neodymium magnets so it can sit on top of the fridge or even hang off the side if I want. Probes - currently I have a single 3m, 2 are 2m and one is 5m long. As I said, they are quick-connect with 1/8" headphone jacks and I have plenty of more sensors I can wire up if I want. if I decide I want to **** up my eyesight even more! lol

[Michael_in_TX]

Thank you for writing all this up! I've been itching to do another RPi or Ardunio project and this looks fun and.....at the end of the days serves a very useful purpose.

And..... I just recently had to up my reading glasses from 1.5x to 2x, so I need to get me one of those serious helping hands with the big magnifiers. Sigh.

[realdocBBQ]

I'll post some more pics and such when I get it all buttoned up and mounted. I ordered coin magnets and screws to attach the top cover as well as some plastic wire tags I can write probe numbers on - right now I just have some tape used as tags with numbers on them. I may go ahead and wire up some more probes as well for a total of 8, to have 2 per cooler. We'll see if my eyes can handle that. Lol

[realdocBBQ]

Just checked and it's not reporting this morning - I'll figure out why and report back. After I finish some coffee. Lol

[Smoker_Boy]

You jinxed my Ender 3 printer.

I had to order a new one.
Can't fix everything.

[realdocBBQ]

Waaaat???? What happened???

[Smoker_Boy]

It stopped communicating through the USB. The connector on the printer had gotten damaged a couple of years ago. I managed to solder it back to where it would work.

But for the past 3 weeks, it's ability to speak to Cura just got worse and worse.

That's OK, I got the good out of this one.
And I found a new exact replacement for $165. So now I got a bunch of parts.

My wife says having a 3D printer is like getting Christmas presents all year long.
(Happy wife, happy life)

[DaveD]

That is some dedication! I have the same need, I'd like to have temp monitoring in both compartments of both fridges, but I won't be going to all this effort! Coupla cheap probes will do me fine

[realdocBBQ]

Ok, oh man, I found out my problem - just that I updated the sensor names in my Python code before going to bed, so my Pi was sending data all night to InfluxDB, but Grafana stopped seeing what it was looking for because I didn't update the "sensor_name" in my Flux code there. Wow. DUH!

So now I've corrected all that AND added in a second panel for each sensor showing a graph of temps over the last 12 hours. Really cool to see how the fridges/freezers all fluxuate differently. I see my "meat Fridge" fluxuates evenly and regularly from about 27F-41F. I don't really like that. I need to see if there's some way to tighten that up a bit, I'm not sure. But I can also see how much changing the cooling intensity knob inside the fridge changes things - I've learned to keep it between 4-5, if I go above 5, it freezes everything in the bottom.

So, I've got a lot of adjusting and learning to do. Here's how my dashboard looks at the moment. Still want to adjust some colors and things to match more appropriately the temps, etc.




You can see it live here:

@realdocBBQ Garage Fridge/Freezer monitoring page

This is a neat project, I'm learning a lot - about coding, about Pi units, about thermometers, MORE about coding and databases, and ALSO about how my fridges and freezers work in the garage, optimally or suboptimally. Makes me think...

I'm seriously loving this, though!

[synodog]

I’ve been wanting to get probes for my garage freezer after having lost two batches of meat when the door doesn’t get closed properly. Of course, I wanted a probe with a hub that reports to an app on my phone so I can see an alarm situation.
Still haven’t bought one yet.
This looks like fun though.

[realdocBBQ]

Yes I'll set it up with both text and email alarms for temps out of range, once I get everything solidified.

[Mosca]

This is the kind of thing FireBoard or ThermoWorks or any of those folks should do. Why not have a probe inside a freezer and/or refrigerator, sending a signal to your router where the temp can be monitored in the app, with an alarm? I’d pay for that.

[jfmorris]

I have Thermoworks fridge alarms on my garage fridges (2) and deep freeze (1), but they are low volume alarms I have to walk into the garage to hear. This is what I use on my beer kegerators to control temp, and the Inkbird app has low and high alarm settings:

https://www.amazon.com/dp/B07PVBG8K1

On Prime Day(s) this was $20 less, going for $29 on the wifi version I think. They go on sale every Black Friday and Cyber Monday as well.

[Mosca]

I have a ThermoWorks freezer thermometer, but it isn’t connected to any app. It beeps, but it’s a “What’s that beep?” type of beep.

[Michael_in_TX]

Just checked and it's not reporting this morning - I'll figure out why and report back.

This can be the odd thing about these monitoring projects. What monitors the monitor?

I have an RPi on my roof (All-sky camera) and RPis do not like heat. They like Texas heat even less and it tends to lock up.

[jfmorris]

The newest Pi 5 runs MUCH hotter than the older ones, and requires a heatsink and cooling fan to get full performance. I have an old Pi 3 running just fine to display beer tap information above my beer taps in a 95 degree garage (this time of year). My worst issue with Pi's is SD card corruption.

[Santamarina]

Almost went down the RPi trail years ago for monitoring temps on my beer fermentation fridge. Ended up just going with a Johnson temp controller. No remote monitoring, but whenever I checked it it was right on the money. Eventually bought a stainless conical with integrated heating and cooling.

[Smoker_Boy]

I used Johnson controllers back when I used to homebrew.
Always worked and accurate too.

[realdocBBQ]

Alright, I've made some changes that I THINK are working and will help the user interface a bit.

If you guys could check these links out and let me know if they work, and if you can easily switch back and forth between them, I'd appreciate it. I've done it in Incognito Mode and it seemed to work fine for me, but I'd appreciate any feedback if you don't mind!



@realdocBBQ Temp Monitoring (Desktop)


@realdocBBQ Temp Monitoring (Mobile)


I THINK these should work to effortlessly switch back and forth between them? Let me know!

[acorgihouse]

Forgive me, but I guess I just don't have the wherewithal to do this extensive monitoring on a fridge or freezer? Yeah, I can geek for any number of reasons (you should see my TI calculator, ca. 1977 grad present, that still works and is in my pocketbook.. ) I also understand the inventory $ that can be crammed into a garage freezer.
I have had a home automation system with SmartThings for about ten years, turns the lights off and on, tells me when someone at my door, juggles the thermostat, you name it. SmartThings (Samsung) is not going to be providing support going forward, so I got an aeotec hub that I will likely replace this weekend. I put a couple of simple aeotec temp sensors in each place I want to monitor, a couple years ago, and it keeps track, shows me graphs when I want, and sends me message if temp is outside my chosen parameters. I've had people tell me they would be crazy getting all the info messages I get from my house, but I like knowing everything is working, and that WishyWashy, the washing machine, has completed it's cycle To each his own.

[realdocBBQ]

Forgive me, but I guess I just don't have the wherewithal to do this extensive monitoring on a fridge or freezer? Yeah, I can geek for any number of reasons (you should see my TI calculator, ca. 1977 grad present, that still works and is in my pocketbook.. ) I also understand the inventory $ that can be crammed into a garage freezer.
I have had a home automation system with SmartThings for about ten years, turns the lights off and on, tells me when someone at my door, juggles the thermostat, you name it. SmartThings (Samsung) is not going to be providing support going forward, so I got an aeotec hub that I will likely replace this weekend. I put a couple of simple aeotec temp sensors in each place I want to monitor, a couple years ago, and it keeps track, shows me graphs when I want, and sends me message if temp is outside my chosen parameters. I've had people tell me they would be crazy getting all the info messages I get from my house, but I like knowing everything is working, and that WishyWashy, the washing machine, has completed it's cycle To each his own.

Once it's all up and running and I set up alerts, I'll never worry about it again unless I get an alarm. But I do like the ability to hit a bookmark on my browser and see the temps on my coolers in the garage. And I'm already seeing how I need or may need to adjust my thermostat controls on them. For me, it was about just the challenge and accomplishment of learning something new, useful (to me, lol) and totally out there. Overkill?

YUP!!!

I mean let's face it - I have 3 Weber 22" kettles in my backyard, a Yoder YS480, a Super 55 drum smoker, 2 propane cabinet smokers, a 36-inch Blackstone griddle, an 80-gallon insulated offset (+ 30-gallon vertical chamber) all at my house. And another 110-gallon trailer-mounted offset next to the house, and a 320-gallon trailered offset smoker out at the shop... and working on others to complete and sell. And I regularly use 2 different Fireboards and a Thermopro 4-probe wired thermometer, and I have 3 Thermopro TempSpike wireless thermometers (which I don't really like and seldom use). It's a wonder I don't have the Thermoworks RFX or the Fireboard Pulse yet - still evaluating.

I mean... seriously, are you shocked at this project? How about even 'mildly surprised'?

[acorgihouse]

Nope, not surprised. I am quite accustomed to going into work and not being able to find a nurse, because they are all out on the floor the first 30 minutes of a shift, checking temp logs, freezer logs, fridge logs, defibrillator charges, IV pumps charging, all that. I'm also accustomed to deciding what is worth the effort, and what info I really don't need. So, as I said, to each his own.

[realdocBBQ]

If nothing else, my experiment has opened my eyes to temp fluctuations and things in my fridges.

My main meat fridge swings wildly from 26-40 or so. Interesting, I don't know that I want to turn the temp down any more and risk freezing in the bottom section, as I've experience that already before. One suggestion I got from Skippy (my personal AI chatbot) was to put a number of gallon jugs filled with water to act as a temp modulator by holding heat (cold) and this can reduce the amplitude of fluctuation. Since that fridge is mostly empty (just a couple 12-packs of beer in there right now), he says a large, mostly empty fridge will fluctuate more wildly up and down. So I may give that a shot. This fridge is also much lighter weight, it feels quite flimsy, so I know it isn't just light gauge steel on the outside, it's also probably only very lightly insulated.

My second fridge (the side-by-side) was running up to 41F or so and I didn't like that, it mostly stayed 38-41. So I set it to one notch colder earlier today and it is now running from 36-38.4 or so with very tiny ups and downs. I may experiment with kicking it up one more notch (which would be the coldest setting) in a day or two. It also is pretty empty at the moment, though since it is a much smaller compartment AND has a solidly frozen freezer right next to it, the variation in temps is much lower than the other fridge.

So I'm enjoying the monitoring and analysis aspects of this whole project.


Now I'm even thinking about building another unit with thermistors and high-temp K-type thermocouples to do in-depth temperature mapping on the offset smokers I build. Even considering a couple of 2,000ºF-rated Inconel-coated thermocouples to see the temps inside the throat opening and even inside the firebox itself. Doesn't that sound freaking AWESOME???? I could even build a battery pack to run it, but I'd need approximately twenty 18650-cell batteries to do so - not that that is out of the question at all! Man, I love tinkering!

[gboss]

Don't need the inconel coatings. Just get some ceramic insulators, e.g. :

https://www.tiptemp.com/TIPTCK132P01-Replacement-K-type-Thermocouple-with-Ceramic-Insulators

Good to about 21-2200F before the junction starts to get mushy.