#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

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

long countdownTime = 300; // 5 minutes in seconds

int ledpin =19;// define pin 10 for LED 
int button =18;// define pin 5 for Push Button 
int val;// Define the variable value 

void setup() {
  Serial.begin(115200);

  pinMode(ledpin, OUTPUT);// define LED as output 
  pinMode(button, INPUT);// define button as input 

  // Initialize OLED display with I2C address 0x3C
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }

  display.display();
  delay(2000); // Pause for 2 seconds
  display.clearDisplay();

  // Display initial countdown time
  displayCountdown(countdownTime); 
}

  //Medicion de boton
void loop() 
{ 
   if (countdownTime > 0) {
    delay(1000); // Wait for 1 second
    countdownTime--; // Decrease the countdown time
    displayCountdown(countdownTime);
  }
   val = digitalRead(button);//Read digital pin 5 level value assign 
   if (val==1)// Test button is pressed 
    { 
     digitalWrite(ledpin, HIGH); 
    } 
   else 
   { 
     digitalWrite(ledpin, LOW); 
   } 
}

void displayCountdown(long seconds) {
  int minutes = seconds / 60;
  int remainingSeconds = seconds % 60;

  display.clearDisplay();
  display.setTextSize(2); // Draw 2X-scale text
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 20);

  if (minutes < 10) {
    display.print("0");
  }
  display.print(minutes);
  display.print(":");
  if (remainingSeconds < 10) {
    display.print("0");
  }
  display.print(remainingSeconds);

  display.display();
}