Maquina_Cafe_v_18.07.27_beta.ino

int ThermistorPin = A0;    // blue wire
int Vo;
float R1 = 5000;       // 5000 47Kohms
float logR2, R2, T, Tc;
float c1 = 1.009249522e-03, c2 = 2.378405444e-04, c3 = 2.019202697e-07;
const int ButtonCoffee  = 12;     // brown wire
const int RelayBoiler   = 11;     // yellow wire
const int RelayCoffee   = 10;     // green wire
const int LedPower      = 9;      // orange wire
const int setTemp    = 95;
const int Hysteresis = 5;
int buttonState      = 0;        // current state of the button
int lastButtonState  = 0;        // previous state of the button
int ledState         = 0;        // remember current led state

void setup() {

  pinMode(ButtonCoffee, INPUT);   // brown wire
  // resistor is in positive side, "pullup", so RelayCoffee must be low level trigger
  pinMode(RelayCoffee, OUTPUT);   // green wire
  pinMode(RelayBoiler, OUTPUT);   // yellow wire
  pinMode(LedPower, OUTPUT);      // orange wire
  digitalWrite (RelayBoiler, LOW);
  digitalWrite (RelayCoffee, HIGH);  // low level trigger
  digitalWrite (LedPower, LOW);
}

void loop() {
  digitalWrite (LedPower, HIGH);
  Boiler();
  Coffee();
  Error();
}

void Boiler() {

  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;
  if ( Tc > 0 && Tc < (setTemp - Hysteresis) )    // cold
{
  digitalWrite (RelayBoiler, HIGH);
}
  else if ( Tc > setTemp )        // hot
{
  digitalWrite (RelayBoiler, LOW);
}
  delay(200);               // delay between ntc readings
}

void Coffee() {
  buttonState = digitalRead(ButtonCoffee);
  if (buttonState != lastButtonState)
{
  if (buttonState == 1)
{
  if(ledState == 1) ledState=0;
  else            ledState=1;
}
  lastButtonState = buttonState;
}
  digitalWrite(RelayCoffee, ledState);
  delay(20);               //debouncing
}

void Error() {
  if ( Tc < 0 )        // error
{
  digitalWrite (RelayBoiler, LOW);
  digitalWrite (LedPower, LOW);
  delay(500);
  digitalWrite (LedPower, HIGH);
  delay(500);
}
}