Tired of bad thermometers, built my own

Discussion in 'Meat Thermometers' started by drygravytrain, Apr 12, 2015.

  1. drygravytrain

    drygravytrain Newbie

    The first problem I ran into when I started smoking about 8 months ago with my MES 30, was all the thermometers suck.  So what did I want in my ideal thermometer? Multiple high quality probes, and the flexibility to add different types of probes. I wanted to be able to check the temp remotely without having to go out to the smoker.  And, I wanted the outside portion to be waterproof. Last, I wanted to be able to track all of my smoke's temps and recipes( I am a deveoper and nerd that loves graphs and data ).

    So I set out to solve all these issues and came up with what is currently dubbed the 'pimometer'.  Its a Raspberry Pi based thermometer with dual thermocouples, wifi enabled with web based front end, and its fully enclosed in a waterproof case.  As a prototype it is built with easily accessible 'off the shelf' components.  I have used it several times now.  Its highly reliable and I dont have to stick it in a plastic bag.


    My probes dont use those stupid mono jacks that always seem to break, it uses a simple two prong thermocouple mini connector.  My probes come from Auberins.com, I have a straight probe and an alligator tipped one both 6ft in length. One usb port is for the Wireless adapter, which you cant see, and the other goes to the thermocouple module which you can see on the top of the case.  Finding the thermocouple module was probably the hardest, but finally found what I wanted from a small company in Norway.

    After you plug it in and after a few seconds, it automatically connects to my wireless network and I can navigate to its IP Address to find the web app.  The web portion is still a work in progress, but it currently displays the temp of each sensor, and all the back-end is written to store and graph the data for Events.  

    Currently in the works or slated for future development :

    - Line Graph / Table view of any Event.

    -The blue circled numbers in the corner of each sensor will be the target temperature you set, which would send you notifications (sms, email, in app etc) that the temperature is reached.  

    -Save recipes / rubs used for each cook 'event'.  

    -Interval timers to remind you of anything such as adding chips.

    -Tagging within an event. Used for indicating when you foiled, moved to the oven, stopped adding smoke, turned up/down the heat etc..


    Currently the web interface is located at https://github.com/gravytrain/automation-interface, and the backend database project is at https://github.com/drwahl/pimometer. Was working on this with a friend, and most likely the two projects will be merged soon into the pimometer repo.  As a prototype this definitely wasnt the cheapest option (though i think shipping parts was half the cost), but it definitely gives me piece of mind that everything will just work, and that I can find replacements parts / probes if needed.
    bmaddox and dirtsailor2003 like this.
  2. timberjet

    timberjet Master of the Pit

    SKILLS. You going to make it wireless or wifi or both? Nevrmind I see now.
    Last edited: Apr 12, 2015
  3. inkjunkie

    inkjunkie Master of the Pit

  4. Hey, I want One !!!

  5. timberjet

    timberjet Master of the Pit

    He just built a better Igrill or thermoworks. One that works on your wifi network I think. Now this stuff is just about way over my head but I'm trying. I smell something burning. Oh, that's just my brain.
  6. dirtsailor2003

    dirtsailor2003 Smoking Guru OTBS Member

    Nice work! Way above my computer skills!

  7. sota d

    sota d Smoking Fanatic

    That makes my head hurt just thinking about it! Very cool though, great job!
  8. drygravytrain

    drygravytrain Newbie

    Yes, very similar to the iGrill.  At the time I started this, the iGrill was Apple only I think, so I wanted something that was accessible on any device.  iGrill is bluetooth, which I considered, but ultimately decided that the distance is unreliable and limited. I also have access to a wider variety of probe types ( I could get a liquid probe to use for brewing beer if I chose ).

    I only have two probe capabilities, but could expand this to 4 or 6. 

    ThermoWorks probes were a bit pricey for my needs, but are compatible and should just be plug and play.
  9. I'm thinking he needs to send out a few for testing,  

  10. drygravytrain

    drygravytrain Newbie

    I am looking for a way to get the price down and get it all into a more compact 'production' enclosure.  If you guys could have the perfect thermometer what would it look like?  More probes, maybe?  What kind of features would you want on the web interface?
  11. inkjunkie

    inkjunkie Master of the Pit

    I have Thermoworks probes....is this something that you are going to be selling at some point?
  12. drygravytrain

    drygravytrain Newbie

    I have been considering selling them as either whole prebuilt units and /or as a kit. But everything is open source so someone can build their own if so inclined.
    Last edited: Apr 12, 2015
  13. Pretty Neat
  14. gunkle

    gunkle Meat Mopper

    Looks good. I just started building something similar called the heatmeter. It only has one thermocouple for the pit and 3 thermistor probes for meat. Also uses a raspberry pi. Is on github https://github.com/CapnBry/HeaterMeter/wiki/HeaterMeter-4.2-Hardware and support is on another grilling forum so I won't post links to the support site. It's my first real soldering to a board project. So far so good.
  15. drygravytrain

    drygravytrain Newbie

    Yea, I had seen the heatermeter, and it appears to be a decent solution, but still has most of flaws that drove me to make my own...bad UI, still needs a decent enclosure that is waterproof, and it's still using those mono jacks.

    I also wanted everything 'off the shelf', no soldering, no custom boards.  And then ultimately, something that anyone can just snap together with no programming and little technical know-how. 
  16. Very cool indeed, you asked about the dream thermometer, I think something compact, maybe with some sort of mounting system that could let you mount it under your shelf or something. Easy to set up, easy to adjust, something for the technology challenged like myself
  17. timberjet

    timberjet Master of the Pit

    Waterproof, maybe a recharging system similar to a cell phone? Network connectivity, programability for high, low temp alarms, 4 probes and a small lcd screen and I would be happy. That would be the perfect device to me. I just want something that works with my Windows phone and my PC. Hardly anything works with this phone.
    Last edited: Apr 13, 2015
  18. inkjunkie

    inkjunkie Master of the Pit

    Understand about them being open source, if you do decide to sell them as a kit,price dependant, I would be interested.
  19. lemonduck

    lemonduck Newbie

    I've been looking to do something like this.

    This is AWESOME!!!   :)

    I got a question about the HeaterMeterPi schematic: you have the pit probe going through the preamp circuit (AD849x), but not the other probes?

    K-type thermocouples produce mV output, I'm just trying to figure out how you get all the readings in with one preamp?

    Am I missing something?
  20. drygravytrain

    drygravytrain Newbie

    The other probes for the heatermeter are thermistor not thermocouple.

Share This Page