/*
    Note

    wokwi 
    1) permit to supply external devices using +5V PIN
       it is not possible in real cases
    2) don't permit the use resistor partitores
    3) see https://docs.wokwi.com/parts/board-ssd1306
    4) ...... see all wokwi advices and instructions .....


    
    Max Korrad Team
    https://www.facebook.com/groups/883620498953478
    
*/
#include <stdio.h>

#include <Wire.h> // protocollo i2c per settare ad esempio la velocità
#include <Adafruit_GFX.h> // font
#include <Adafruit_SSD1306.h>

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define reset_interrup -2
#define wait_interrupt -1
#define button_st       4 
#define button_up       3 
#define button_dw       2 

volatile int new_state=-1;   
volatile int state=0;
volatile bool up=false, dw=false;
int old_state=0;

void call_up() {
    // call interrupt
    detachInterrupt(digitalPinToInterrupt(button_up)); 
    up=true;
    new_state=state+1;  
}

void call_dw() {
    // call interrupt
    detachInterrupt(digitalPinToInterrupt(button_dw)); 
    dw=true;
    new_state=state-1;  
}


//long int  blink_duration  =  300;
int  start_h=00, start_m=00, clk=53;
char outstr[30];

void reset_watch (void) {
  // RTC setup simulation
  start_h=00;
  start_m=00;
  clk=53;
}

void clock(void) { 
  // clear
  display.setTextSize(2);              // 2:1 pixel scale
  display.setCursor(25, 0);
  display.setTextColor(SSD1306_BLACK);
  sprintf(outstr,"%02d:%02d:%02d",start_h,start_m,clk);
  display.print(outstr);
  
  // tic RTC simulation
  if(clk==59) {
    
    if(start_m==59) {
      if(start_h==23) start_h=0;
      else start_h++;
      start_m=-1;
    }
    start_m++;
    clk=-1;  
  }
  clk++;
    
  // print
  display.setCursor(25, 0);
  display.setTextColor(SSD1306_WHITE);
  sprintf(outstr,"%02d:%02d:%02d",start_h,start_m,clk);
  display.print(outstr);
  display.display();
  
}


ISR(TIMER1_COMPB_vect) {
    
    digitalWrite(8,HIGH); 
    digitalWrite(9,HIGH); 
  
}

ISR(TIMER1_COMPA_vect) {
    state =3;
    digitalWrite(8,LOW); 
    digitalWrite(9,LOW);
    
}

ISR(TIMER1_OVF_vect) {
 
    digitalWrite(8,HIGH); 
    digitalWrite(9,LOW);
    
       
    /* with TCNT1 > 0  timer1 will start from this value e not zero*/
    //TCNT1=15000; 
  }



void setup() {
  Serial.begin(9600);  // initialize the serial port:
  //cli(); // Nointerrupt

/*

    {
      "type": "wokwi-ssd1306",
      "id": "ssd1306",
      "top": -112.62,
      "left": 1.39,
      "attrs": { "i2c-address": "0x3D" }
    },
    [ "uno:5V", "ssd1306:VIN", "red", [ "v19.24", "h-165.59", "v-423.92", "h287.17" ] ],
    [ "ssd1306:DATA", "uno:A4.2", "violet", [ "v-21.61", "h-362.75", "v188.24", "h86.53" ] ],
    [ "ssd1306:CLK", "uno:A5.2", "blue", [ "v-28.64", "h-379.26", "v198.94", "h84.04" ] ],
    [ "ssd1306:GND", "btn1:1.r", "black", [ "v-34.74", "h59.57", "v163.2", "h-0.08", "v15.48" ] ],


  { "type": "board-ssd1306", "id": "oled1", "top": -16.91, "left": -128.06, "attrs": {} },
      [ "oled1:VCC", "uno:5V", "red", [ "v-32.43", "h77.3", "v289.31", "h-276.71" ] ],
    [ "oled1:SCL", "uno:A5", "blue", [ "v-23.09", "h61.81", "v267.45", "h-175.17" ] ],
    [ "oled1:SDA", "uno:A4", "purple", [ "v-13.09", "h46", "v226.46", "h-178.69" ] ],
    [ "oled1:GND", "btn1:2.l", "black", [ "v-18.78", "h-48.49", "v-76.54" ] ],

*/



  TCCR1A = 0;
  TCCR1B = 0;
  TCCR1B |= (1 << CS11); //(1 << CS11)|(1 << CS10);(1 << CS12)|
  TCCR1B |= (1 << WGM10); 
  //TCCR1B |= (1 << WGM12); //CTC : with CTC led1 don't work
  OCR1A = 37000;
  OCR1B = 26000; 
  TIMSK1 |= (1 << OCIE1B);
  TIMSK1 |= (1 << OCIE1A);
  TCNT1=0; 
  TIMSK1 |= (1 << TOIE1);
  /*  */
    

  // Display setup
  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3D)) { // Address 0x3D for 128x64
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }
  display.clearDisplay();              // no logo 

  

  pinMode(button_st,INPUT_PULLUP);
  pinMode(button_up,INPUT_PULLUP);
  pinMode(button_dw,INPUT_PULLUP);
  pinMode( 8,OUTPUT);
  pinMode( 9,OUTPUT);
  pinMode(13,OUTPUT);

  //PORTB|=B00100000;
  //PORTB&=B11100000;
  
  
  display.setTextSize(2);              // 2:1 pixel scale
  display.setTextColor(SSD1306_WHITE); // Draw white text
  display.setCursor(36, 22);           // top-left corner
  display.cp437(true);                 // Use full 256 char 'Code Page 437' font
  display.write("START");
  display.display();
   
  // Abilita interrupt
  attachInterrupt(digitalPinToInterrupt(button_up),call_up,FALLING);
  attachInterrupt(digitalPinToInterrupt(button_dw),call_dw,FALLING);
  
  int new_state=-1;   // numero trasmesso
  int state=0;
  bool up=false, dw=false;
  int old_state=0;


  //Serial.println(state);
  display.setTextColor(SSD1306_BLACK); // Draw white text
  display.setCursor(36, 22);           // top-left corner
  display.write("START");
  delay(800);
  digitalWrite(13, LOW);
  display.setTextSize(4);              // 4:1 pixel scale
  display.setTextColor(SSD1306_WHITE); // Draw white text
  display.setCursor(56, 20);           // top-left corner
  display.write("0");
  display.display();

    sei(); // ok interrupt

}

void loop() {
  bool start_flag=false;
  static unsigned long now,last=0L;   // clock
  static int i,k=0;                   // tic clock x funzione reset_watch di debug
    
  // CTR simulation (each one can choice if introduce the CTR or not)
  now=millis(); 
  if( (now-last) > 1000) 
  { 
    clock(); 
    last=now; 
           
    // only for debug
    k++;
    if(k==600)
    { // reset abaut each 30 minutes
      k=1;
      reset_watch();
  } }

  if(!start_flag)
  {

    // start_flag=true;
  }
  
    switch(new_state)
    { case reset_interrup:
          
          if(state!=old_state) 
          { digitalWrite(13, HIGH);
            // during LED13 ..... 
            display.setTextSize(4);              // 2:1 pixel scale
            display.setTextColor(SSD1306_BLACK); // Draw white text
            display.setCursor(56, 20);           // top-left corner
            display.write(old_state+48);
            display.setTextColor(SSD1306_WHITE); // Draw white text
            display.setCursor(56, 20);           // top-left corner
            display.write(state+48);
            display.display();

            old_state=state;
          }

          //debouncing
          if( (PIND&B00001000) && (PIND&B00000100)) delay(200);
          
          //reset
          if( (PIND&B00001000) && (PIND&B00000100))
          {
            if (up && state<5)
            { attachInterrupt(digitalPinToInterrupt(button_up),call_up,FALLING); 
              up=false;
            }
            { attachInterrupt(digitalPinToInterrupt(button_dw),call_dw,FALLING); 
            if (dw && state>0)
              dw=false;
            }
            new_state=wait_interrupt;
            digitalWrite(13, LOW);
          }          
            
          
        break;
      case wait_interrupt:
          // wait state
          // aspetto un click
          
          break;
      case 0:
       
        new_state=reset_interrup;
        old_state=state;
        state=0;
        break;
      case 1: 
       
        new_state=reset_interrup;
        old_state=state;state=1;
        break;
      case 2:
        
        new_state=reset_interrup;
        old_state=state;state=2;
        break;
      case 3:
       
        new_state=reset_interrup;
        old_state=state;state=3;
        break;
      case 4:
       
        new_state=reset_interrup;
        old_state=state;state=4;
        break;
      case 5:
       
        new_state=reset_interrup;
        old_state=state;state=5;
        break;
      case 6:

        new_state=reset_interrup;
        old_state=state;
        break;
      default:
        new_state=reset_interrup;
        break;
    }
} 

// Max KORRAD Team
// FB: Elettronica Hobby Arduino https://www.facebook.com/groups/883620498953478