Arduino Franken-Timer for George Foreman Grill. ESP32-S2 with Hardware SPI to OLED screen. Tune on simple speaker.

George_Foreman_Timer_02.ino

#include "pitches.h"
#include "CountDown.h"
#include <Adafruit_GFX.h>    // Core graphics library
#include <Adafruit_ST7789.h> // Hardware-specific library for ST7789
#include <Fonts/FreeSans24pt7b.h>
#include <SPI.h>

#define TFT_CS   10
#define TFT_RST  7 
#define TFT_DC   5
#define TFT_MOSI 35  // Data out
#define TFT_SCLK 36  // Clock out

Adafruit_ST7789 *_tft = NULL;

CountDown CD;

// Use interrupts for Button input
volatile unsigned long Debounce1Timer;
volatile int Button1Pressed=0;
volatile unsigned long Debounce2Timer;
volatile int Button2Pressed=0;
volatile unsigned int delayTime = 500;

// Pins
// Button 1 is Start/Stop/Reset
// Button 2 in increment counter
int button1Pin = 6;
int button2Pin = 2;
int speakerPin = 39;
int relayPin = 3;

void debouncer1(){
  if (Button1Pressed+= (millis() - Debounce1Timer) >= (delayTime )) Debounce1Timer = millis();
}

void debouncer2(){
  if (Button2Pressed+= (millis() - Debounce2Timer) >= (delayTime )) Debounce2Timer = millis();
}

int prev_minute = 0;
int prev_second = 0;
int countdown_running = 0;

// notes in the melody:
int melody[] = {
  NOTE_C4, NOTE_G3, NOTE_G3, NOTE_A3, NOTE_G3, 0, NOTE_B3, NOTE_C4
};

// note durations: 4 = quarter note, 8 = eighth note, etc.:
int noteDurations[] = {
  4, 8, 8, 4, 4, 4, 4, 4
};

char countdownDisplay[6];

void setup() {

  Serial.begin(115200);

  // Button Pins. Implemented as Interrupt so it should never miss a trigger.
  pinMode(button1Pin, INPUT_PULLUP);
  pinMode(button2Pin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(button1Pin), debouncer1, RISING);
  Button1Pressed=0;
  attachInterrupt(digitalPinToInterrupt(button2Pin), debouncer2, RISING);
  Button2Pressed=0;

  pinMode(speakerPin, OUTPUT);

  // Setup the relay to OFF
  digitalWrite(relayPin, 0);
  pinMode(relayPin, OUTPUT);

  // Hardware SPI - Many times faster than software
  SPIClass *spi = new SPIClass(HSPI);
  spi->begin(TFT_SCLK, -1, TFT_MOSI, TFT_CS);
  _tft = new Adafruit_ST7789(spi, TFT_CS, TFT_DC, TFT_RST);
  // 80MHz should work, but you may need lower speeds
  _tft->setSPISpeed(80000000);
  // this will vary depending on your display
  _tft->init(240, 280, SPI_MODE0);

  _tft->setFont(&FreeSans24pt7b);
  _tft->setTextSize(2);
  _tft->setRotation(3);
  _tft->fillScreen(ST77XX_BLACK);
  _tft->setTextColor(ST77XX_WHITE, ST77XX_BLACK);

  // large block of text
  int16_t x1, y1;
  int x, y;
  uint16_t w, h;

  _tft->getTextBounds(countdownDisplay, x, y, &x1, &y1, &w, &h); //calc width of new string
  //_tft->setCursor(x - w / 2, y); 
  _tft->fillRect(35, 35, 230, 110, ST77XX_BLACK);
  _tft->setCursor(35,140);
  strncpy(countdownDisplay, (char *)"00:00", 5);
  _tft->print(countdownDisplay);

}

void loop() {
  uint32_t t;
  
  // Button 1 is Start/Stop/Reset
  if (Button1Pressed > 0){
    Serial.println("Button 1 Pressed");
    Button1Pressed = 0;
    // If already running - Stop and Reset
    if (countdown_running == 1){
      
      // Active HIGH so write 0 to deactivate relay
      digitalWrite(relayPin, 0);

      countdown_running = 0;
      prev_minute = 0;
      prev_second = 0;
      CD.stop();
      strncpy(countdownDisplay, (char *)"00:00", 5);
      _tft->fillRect(35, 35, 230, 110, ST77XX_BLACK);
      _tft->setCursor(35,140);
      _tft->print(countdownDisplay);
      for (int thisNote = 0; thisNote < 8; thisNote++) {
        int noteDuration = 1000 / noteDurations[thisNote];
        tone(speakerPin, melody[thisNote], noteDuration);
        int pauseBetweenNotes = noteDuration * 1.30;
        delay(pauseBetweenNotes);
        noTone(8);
      }
    // If not running and there's a duration set - start running  
    } else if ((countdown_running == 0) && (prev_minute != 0)) {
    
      // Active HIGH so write 1 to activate relay
      digitalWrite(relayPin, 1);

      CD.start(0, 0, prev_minute, prev_second);
      countdown_running = 1;
      sprintf(countdownDisplay, "%02d:%02d", prev_minute,prev_second);
      _tft->fillRect(35, 35, 230, 110, ST77XX_BLACK);
      _tft->setCursor(35,140);
      _tft->print(countdownDisplay);
    }
  }

  // Button 2 is Incremement Counter
  if (Button2Pressed > 0){
    Serial.println("Button 2 Pressed");
    Button2Pressed = 0;
    // Is already running - add 1 to the minute timer
    if (countdown_running == 1){
      prev_minute = (prev_minute + 1) % 30;
      sprintf(countdownDisplay, "%02d:%02d", prev_minute,prev_second);
      _tft->fillRect(35, 35, 230, 110, ST77XX_BLACK);
      _tft->setCursor(35,140);
      _tft->print(countdownDisplay);
      CD.stop();
      CD.start(0, 0, prev_minute, prev_second);
    } else {
      prev_minute = (prev_minute + 1) % 30;
      prev_second = 0;
      sprintf(countdownDisplay, "%02d:%02d", prev_minute,prev_second);
      _tft->fillRect(35, 35, 230, 110, ST77XX_BLACK);
      _tft->setCursor(35,140);
      _tft->print(countdownDisplay);
    }
  }

  if (countdown_running == 1){
    t = CD.remaining();
    int s = t % 60;
    int trem = (t - s)/60;
    int m = trem % 60;

    if (s != prev_second){
      Serial.print("Remaining: ");  
      Serial.print(m);
      Serial.print("m ");
      Serial.print(s);
      Serial.println("s");

      sprintf(countdownDisplay, "%02d:%02d", m,s);
      _tft->fillRect(35, 35, 230, 110, ST77XX_BLACK);
      _tft->setCursor(35,140);
      _tft->print(countdownDisplay);
    }

    prev_minute = m;
    prev_second = s;

    if (t == 0){

      // Active HIGH so write 0 to deactivate relay
      digitalWrite(relayPin, 0);

      CD.stop();
      countdown_running = 0;
      prev_minute = 0;
      prev_second = 0;
      sprintf(countdownDisplay, "%02d:%02d", m,s);
      _tft->fillRect(35, 35, 230, 110, ST77XX_BLACK);
      _tft->setCursor(35,140);
      _tft->print(countdownDisplay);

      for (int thisNote = 0; thisNote < 8; thisNote++) {
        int noteDuration = 1000 / noteDurations[thisNote];
        tone(speakerPin, melody[thisNote], noteDuration);
        int pauseBetweenNotes = noteDuration * 1.30;
        delay(pauseBetweenNotes);
        noTone(8);
      }
    }
  }
  delay(100);

}