Smoke&Temp Master


BBQ Smoker Control System



Machining

The low cost milling center was handy in drilling holes in fan housing.

 



3D Printing with PLA

The fan housing was printed with 1.75mmPLA. The butterfly valve was attached direct to the servo horn.



Evan Varghese  

McKinney High School. Senior. Coder. Maker. Creator. Interests in science & technology. Enjoys eating BBQ more than cooking. Developer of Smoke&Temp Master BBQ Control System. 


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The System

The overall system with AFCM and controller. A stand alone 7" monitor made the system portable. 

  



Air Flow Control Mechanism  

AFCM is attached to the smoker and has a blower fan and a butterfly valve controlled by a servo.

 



Raspberry Pi- Controller

The controller has the Raspberry Pi microcomputer with Adafruit Motor driver and temperature sensing board. The two K type thermo couples are attached to MAX6675 amplifiers.



Maker Experience

Maker ExperienceComputer Aided Design● Autodesk Inventor● Autodesk Fusion● Adobe IllustratorMicrocomputer & Microcontroller● Raspberry Pi – build, code, hats● Arduino - build, code, shieldsMachining & Assembly● Machining & Fabrication:Milling, Cutting● Electronics Systems:Assembly, SolderingComputer Aided Machining●Additive Manufacturing- 3D printing (PLA)● CO2 Laser Cutting & Engraving  





The Air Duct

The air duct design went through many trials. The design was done in Autodesk Fusion 360.  




PWM Based Motor Control

The blower fan speed is regulated with the PWN signal through the Adafruit Motor hat. The PWM was tuned to run fan at half speed.



The Infamous Stall

The brisket goes through a phase in which the internal meat temperature does not raise with time This can dry out the bark and most use a foil to warp the brisket during stall.  




Python

Most of the coding was done in Python. The GUI was developed in TKinter. 

 



Raspberry Pi

The heart of the control system. Adafruit motor driver hat was used to interface with blower motor. The butterfly valve servo was connected direct to GPIO.   





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The Smoke

The hickory infused smoke was controlled by the air flow. With some trial and error the smoke temperature was maintained. at 240F the amount was smoke coming out was minimal   



The Smoke Ring

The pink smoke ring was deep and even, maybe due to the constant temperature and absence of foil. Even the fat side of brisket had smoke ring.



Eliminating Texas Crutch

Texas crutch is the wrapping short cut taken to shorten the cooking time during smoking beef briskets. Smoke&Temp system aims to eliminate the need for wrapping.  


Laser Cutting

The CO2 laser cutter was used to make the controller base out of acrylic. but controlling the speed and laser power it can be used to 'engrave' on acrylic. 




Hardwood Charcoal

The fuel and flavor source. Though not homogenous, the lump charcoal was consistent enough to be controlled with air flow. 

  



BBQ Brisket

A slow smoked at low temperatures tough cut from chest muscles. One of the most difficult to get it right while smoking. When done right, it is BBQ nirvana.