Bread Proofer Arduino Project

proofer.ino

#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

int ThermistorPin = 0;
int relayPin = 10;
int Vo;
float R1 = 10000;
float logR2, R2, T, Tc;
float Tdesired = 27.0;
float c1 = 1.009249522e-03, c2 = 2.378405444e-04, c3 = 2.019202697e-07;

void setup() {
  Serial.begin(9600);
  pinMode(relayPin, OUTPUT);
}

void loop() {

  lcd.begin(16, 2);

  Vo = analogRead(ThermistorPin);
  R2 = R1 * (1023.0 / (float)Vo - 1.0);
  logR2 = log(R2);
  T = (1.0 / (c1 + c2*logR2 + c3*logR2*logR2*logR2));
  Tc = T - 273.15;
  Tc = round(Tc*10)/10.0;
  
  Serial.print(Tc);
  Serial.println(" C");

  lcd.print(Tc,1);
  lcd.print((char)223);
  lcd.print("C");
  lcd.print(" -> ");
  lcd.print(Tdesired,1);
  lcd.print((char)223);
  lcd.print("C");

  if (Tc < Tdesired) {
      digitalWrite(relayPin, HIGH);
      lcd.setCursor(0, 1);
      lcd.print("Heater on");
  } else {
      digitalWrite(relayPin, LOW);
      lcd.setCursor(0, 1);
      lcd.print("Heater off");
  }

  delay(1000);
}