Test#2: It’s ALIVE!
Good news folks!
I am currently running my second test and it is going great! This time I have completed the PID control over the fan and the logic to control the pellet feed. There is a thermocouple driving the cooker temperature control! I am very happy to report that without any tuning of parameters (read as: it can get better) temps are holding within 5° around 350° and 10° at 200°! Temperature changes in the setpoint of about 100° take about 10 minutes to settle.
Here is the details of the test… I started my Traeger using the controller function, from there the controller automatically went into run mode and tried to obtain the default temp of 240°. It reached that temp in about 10 mins from startup but could be faster due to a parameter I needed to change. I waited for the PID calculation to settle and keep the temp within a few degrees which took about 20 mins. I then adjusted the setpoint up to 350°. The cooker took about 10 mins to reach 350° and stayed very stable the whole time within 5 degrees. After a bit I did open the lid for about 15 seconds to see how it was handled. The temp seemed to fully recover within 3-5 minutes. I then decreased the setpoint to 180. I am very concerned about a flameout here, but am re-writing the algorithm to take care of that. In-deed, I did have a flameout, but because of the snazzy web control, I was able to see the temp go below 150° and still not rise and kick on the hot rod. Flameout averted! This will be a automatic function in the future. There is some issues with dropping temp from a much higher temp… no pellets are entering the pot for a long time, and the fire goes out. I am going to work to resolve this. I began the shutdown routine because it is getting late, and I don’t want ot burn through too many pellets without some Q on the grill!
Here is the graph of the cooker temp. I will be doing another test this weekend with some more tweaks!
Anyone else find it both weird and awesome that I am sitting inside my house, while my Traeger is outside in my yard while running this test! 
Hi Ryan,
You have to be so excited, I know I am. Just reading about how far you have progressed is in itself awesome. I agree with you about sitting inside the house and being able to control everything. Wow! Once you zero in on those flameouts and extreme temperature adjustments sounds like you will be close to sending out to the field for testing. So whenever you are ready, I am also ready.
Looking forward to your next posting.
Don O
Pleasant Hill, CA
Thanks! Hopefully I will be able to design up the prototype PCB’s next week and get them ordered. I don’t think you want to test a controller with breadboards and wires that if you bump might break or shock you!
Great news Ryan. Things are coming along faster than I would have expected, and these early results are very promising. Can’t wait to see this controller firsthand.
Eric