#include <SPI.h>	// libraries necessary for running
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // wide of screen OLED
#define SCREEN_HEIGHT 64  // height OLED
#define OLED_RESET -1  // Reset pin (not used in arduino uno)
#define SCREEN_ADDRESS 0x3C  // Standar I2C direction for OLED

// Create an object with oled display
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

int time = 100;

void setup() {
    Serial.begin(9600);  // begin serial
    
    // Connections necessary for arduino uno:
    // SDA -> A4
    // SCL -> A5
    // VCC -> 5V
    // GND -> GND
    
    // starto OLED diplay
    if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) { // Dirección I2C 0x3C
        Serial.println(F("Error at starting"));
        for (;;);
    }
    display.clearDisplay();
    display.setTextSize(2);
    display.setTextColor(SSD1306_WHITE);
    
    for (int n = 9; n <= 13; n++) {  // Repeat from 9 to 13
        pinMode(n, OUTPUT);  // Configure leds as output
    }
}

void loop() {
    static int contador = 0;
    
    for (int n = 9; n <= 13; n++) {
        digitalWrite(n, HIGH);
        delay(time);
        digitalWrite(n, LOW);
        delay(time);
    }
    
    // Mostrar el contador en la pantalla OLED
    display.clearDisplay();
    display.setCursor(10, 25);
    display.print("Counting: ");
    display.print(contador);
    display.display();
    
    contador++;
}