This project involves creating an automated temperature control system for a smoker, ensuring consistent cooking temperatures. The system uses a K-type thermocouple with a MAX6675 amplifier board to monitor temperature, and controls airflow using an SG90 servo motor and a 12V fan. The system dynamically adjusts these components to maintain a set temperature range defined by the user. This system uses 2 potentiometers to set the temperature limits. Made it this way because the user prefered it. This controller can easily be changed to use just 1 potentiometer to set the wanted temperature and diplay the set temperature and the current temperature in the lcd.

During my testing this simple controller has been able to keep the temperature pretty stable. I might continue the developement by adding a more complicated controller later on, but for now this will do.

Key Components

Temperature Sensing:

1. A K-type thermocouple coupled with the MAX6675 amplifier provides accurate temperature readings from the smoker.

Airflow Control:

1. An SG90 servo motor operates a flap to regulate the smoker's airflow.
2. A 12V fan boosts airflow when the temperature is too low.

User Interface:

1. A 16x2 LCD display shows the user-defined temperature limits.
2. Potentiometers allow the user to set the upper and lower temperature limits.

Temperature Control:

When below the minimum temperature:

1. The servo opens the flap to increase airflow.
2. The fan turns on to fuel the fire, raising the temperature.

When above the maximum temperature:

1. The servo closes the flap, restricting airflow.
2. The fan turns off, preventing further temperature rise.

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🛠️ เจาะลึกเบื้องหลังการทำงาน (Deep Dive / Technical Analysis)

Smoking brisket at exactly 225°F for strictly 12 hours is a physical nightmare. A slight breeze or sunlight causes the wood completely to flare up or suffocate utterly! The Wood Smoker Temperature Controller deploys heavy-weight aerospace engineering arrays to construct an absolute automated barbecue! Utilizing an incredibly durable MAX6675 High-Temperature K-Type Thermocouple, the Arduino polls extreme firebox kinetics completely seamlessly. This internal metric does NOT just turn a servo "On or Off." It pipes the variable aggressively into a terrifyingly complex PID (Proportional, Integral, Derivative) Mathematical Controller Loop! The algorithm organically predicts the heat curves natively, spinning an active BLDC fan or twisting a physical Damper Servo iteratively to maintain the exact 225°F coordinate continuously, totally regardless of environmental weather!

Intersecting Sub-Atomic Thermocouple Interfaces (MAX6675)

A standard $1 Thermistor will instantly violently melt entirely inside a 500°F firebox.

1. The K-Type Thermocouple uses two distinctly different extraterrestrial metal alloys welded tightly at a microscopic point completely inside a stainless steel shielded probe!
2. When heated brutally, physics dictates the metals cleanly generate a measurable micro-voltage (The Seebeck Effect natively!).
3. The incredibly complex MAX6675 chip interfaces using high-speed SPI arrays directly intercepting the raw voltage, amplifying it natively, and transmitting absolutely precise integer degrees out to the Arduino perfectly flawlessly up to completely 1800°F!

#include <PID_v1.h>
#include <max6675.h>
#include <Servo.h>

// Initialize complex SPI matrix for the MAX6675 Engine!
int thermoDO = 4; int thermoCS = 5; int thermoCLK = 6;
MAX6675 thermocouple(thermoCLK, thermoCS, thermoDO);

Servo damperServo;

// The Massively Complex Calculus PID Tuning Variables!
double Setpoint, Input, Output;
double Kp=2.0, Ki=5.0, Kd=1.0; // The Proportional, Integral, & Derivative aggressive coefficients!
PID myPID(&Input, &Output, &Setpoint, Kp, Ki, Kd, DIRECT);

void setup() {
  Setpoint = 225.0; // Explicitly locked target Fahrenheit!
  damperServo.attach(9);
  
  myPID.SetMode(AUTOMATIC);
  myPID.SetOutputLimits(0, 180); // Restrict math exclusively to 180 Servo Degrees!
}

void loop() {
  Input = thermocouple.readFahrenheit(); // Aggressively pull absolute fire data natively!
  
  myPID.Compute(); // Execute the terrifying internal PID calculus natively!
  
  // Output is flawlessly calculated to be exactly the servo angle required to maintain the fire!
  damperServo.write(Output); 
  
  delay(1000); // 1-Second absolute thermal buffer interval precisely!
}

Defeating Thermodynamic Lag (PID Tuning)

If the Arduino runs a basic "If less than 225, open damper", the temperature will uncontrollably swing between 180 and 300 forever because charcoal takes explicitly 15 minutes to natively react to fresh oxygen!

• The Derivative (D) metric tracks the "Rate of Change." If the temperature is climbing rapidly from 210 to 220, the PID logic correctly knows that the fire is already accelerating! It natively violently closes the robotic damper halfway early, completely preventing the catastrophic temperature overshoot entirely cleanly!

Robust Grilling Automation Hardware

• Arduino Uno/Nano (To explicitly track identical massive thermal PID tracking calculations natively).
• MAX6675 SPI Module & K-Type Stainless Steel Probe (Absolutely mandated to survive the brutal caustic acidic vapor matrices within the physical smoker seamlessly!).
• High-Torque MG996R Metal Gear Servo (The damper will seize with grease. A completely cheap plastic SG90 servo will shatter all internal gears precisely on day 2. You must utilize massive 15kg/cm Metal Servos entirely!).
• Standard HD44780 16x2 I2C LCD (To output the Current Temp vs Target Temp explicitly preventing laptop deployment beside an open fire!).