HeaterMeter: Automated BBQ and Sous-vide controller

8 posts
by CapnBry » Sat Sep 22, 2012 10:56 pm
Continuing on the success of the LinkMeter Project come the HeaterMeter v4.0 revision for RasbperryPi or standalone use.

HeaterMeter for RaspberryPi joins an Arduino / AVR ATmega328 microcontroller with OpenWrt running on a RaspberryPi $35 wonder-computer for the purpose of providing oven-like control of a charcoal BBQ grill via web interface. The microcontroller controls a fan which limits airflow to the pit, displays the current status on a character LCD, and passes the data on to the RaspberyPi which streams real-time updates to connected web browsers. The website also works on mobile browsers running Android or iOS, allowing users to unchain themselves from their grills and partake in many life-enriching activities such as
  • Going to the grocery store to buy more beer
  • Going to a bar to drink more beer
  • Not get off the couch, where your beer is
  • Possibly other non-beer related hobbies
HeaterMeter is also reportedly suitable for connecting to a solid state relay and controlling a sous vide heater if you prefer your food float around in fancy water instead of smoke and fire.

LinkMeter Home Screen

Project Page - GitHub Hosting
LinkMeter/HeaterMeter is an 100% open source project and is hosted on my GitHub page. The ultimate source for information is the HeaterMeter Project Wiki and the TVWBB SubForum. Open source means you're free to modify it as you see fit. Change the background color to cyan, replace everywhere it says "Pit" with the word "Poo", rewrite the whole thing in Visual Basic or just add a feature I'm too dumb or busy to implement.

A custom PCB mounts directly to the Pi, which handles the heavy lifting of building graphs and serving dynamic web content through AJAX/Server-sent events. 12V input is stepped down to 5V to power the Pi, ATmega328P controller chip, and wireless adapter all from one plug. The ATmega is programmed directly over the SPI bus from the Pi and communicates over the serial GPIO pins.

About $75 in parts, plus probes and a case. HeaterMeter uses probes from a Maverick digital temperature kajigger so if you already have those it will save you some money ($10/ea).

This post is a shameless attempt to draw more attention to the project so I can steal your good ideas and implement them. The main HeaterMeter 4.0 thread but I'm happy to answer any questions here or there.
Posts: 28
Joined: Sun Jan 08, 2012 2:04 pm
by NeilM » Mon Dec 10, 2012 2:18 am
So if I wanted to use this as a 'fancy water' device, would I just replace the RCA jack with a SSR which then controls the good ole fancy water heater, in this case a crockpot, with a probe dangling in aforementioned fancy water? I'd love to use your smokin' device for sous vide, as I've just been given a cookbook that has all sorts of uses for sous vide, and approximately none for smoke... How would I implement that? Thanks for keeping it lighthearted! Neil.
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Joined: Sat Jul 07, 2012 11:25 pm
by CapnBry » Tue Dec 11, 2012 8:24 pm
What I did was just put an RCA jack on the SSR's input and then use an audio cable to connect it to the RCA on the HeaterMeter. I think it would work OK with the default settings, but better results can be achieved by setting the "Min Fan Speed" to 100% in the web interface. This changes the output to be on a 10 second cycle rather than a 500 times a second cycle.

But yeah just dangle the maverick temperature probe in the water. I don't think they're supposed to be submersed so leave the wire end out.
Posts: 28
Joined: Sun Jan 08, 2012 2:04 pm
by NeilM » Thu Dec 13, 2012 12:58 am
Awesome, thanks for the quick response! Neil.
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Joined: Sat Jul 07, 2012 11:25 pm
by NeilM » Tue Feb 19, 2013 2:34 am
Cap'n, got her up and running as a sous vide, just had my first meal - yum! Thanks, your instructions are quite clear, even for an OS newbie like me. Still having issues with getting WiFi to work, but I have a long Cat5 cable...


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by SimonK » Sat May 18, 2013 8:35 am

this project is gr8. could you plz specify which hardware u are using. im a newbie in electronics.
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Joined: Sat May 18, 2013 8:34 am
by DIYMatt86 » Wed Dec 11, 2013 4:50 am
Is anyone selling a completed board? I'm a software guy and have 0 experience with soldering and I have a vision impairment that makes it impossible to learn. I would like one of the to control my new smoker and be my first Raspberry Pi project as well.
Posts: 1
Joined: Wed Dec 11, 2013 4:46 am
by Ajax » Tue Mar 18, 2014 3:26 am
I have my heater meter working and I love it. My next step is to control my pellet grill as well, but not with the heater meter functions. Would I have to purchase another heater meter. Basically I need a pin to drive a Nrf905 radio module to communicate with my grill. At this point I think it would be simpler to go with another RPi. Any thoughts?
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Joined: Thu Oct 31, 2013 5:46 pm