I've been toying with an Arduino woodstove monitoring system for a while now, and would like to share where I've got to. The system expands on Rocket Booster's idea, posted in 2013, and consists of an Arduino processor that retrieves data from multiple thermocouples, an ambient temperature & humidity sensor, and a wideband oxygen sensor. The system, which I've nicknamed stovething (with stovestooge coming a close second, and stovesense howled off the stage), uses off-the-shelf components and outputs to a data logging package.
Details of the prototype system are as follows:
- Two inexpensive K-type thermocouples (the number of thermocouples is limited only by the number of pins on the Arduino board - an Arduino Uno will accommodate at least 4, but bespoke boards are available for up to eight).
Two Adafruit Max MAX31855 breakout amplifier boards for the thermocouples (please note that these boards cannot be used in combination with earthed thermocouples).
An Innovate Motorsports LC-2 controller and Bosch LSU 4.9 wideband oxygen sensor (the expensive bit).
A SparkFun HTU21D temperature and humidity sensor (you don't need this, but it allows you to benchmark your data, a little).
An Arduino Uno R3 development kit (I used a Seeedstudio ARDX kit, but any kit that comes with a breadboard and some other items - see specification - will do).
MakerPlot data logging software.
A 12 volt 3A power supply for the wideband sensor (I used an RS-50-12 Mean Well unit).
A serial port to USB converter if your computer is not equipped with a serial port.
If you wish to replicate the prototype system, or simply want to find out what I've done, I'll happily send you a list of components and suppliers, the wiring diagram, the Arduino software sketch, the interface macro for the logging software, and instructions on how to put it all together. You can contact me by PM (Personal Message).
While I'm confident that the system is capable of retrieving and logging repeatable, accurate data, I have concerns about sensor contamination and durability.
Something tells me that if you can map a given woodstove design long enough using a combination of thermocouples and a wideband oxygen sensor, you will, at some stage, be able to make do without the oxygen sensor. Which would allow you to burn a stove cleanly and efficiently using an affordable and durable thermocouple system. Then again, maybe that's just wishful thinking.
Last but not least, here's a link to a (simple) video showing the above system in operation.