// ##############################################################
//                   OLED SSD1306   Interface                   #
// ##############################################################
// 
//  OLED  interface with Arduino Nano (Hardware & Simulation)
// 
//  Check out the link for Code explanation and Hardware details
//  Link: 
//   http://tech.arunkumarn.in/blogs/arduino-nano/interfacing-128x64-monochrome-oled-ssd1306-with-arduino-nano
// 

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

// --------------------------------------
// OLED Display Configuration
// --------------------------------------
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

// OLED Reset pin (-1 if not used)
#define OLED_RESET -1

// OLED I2C Address (usually 0x3C)
#define SCREEN_ADDRESS 0x3C

// Create OLED display object
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// --------------------------------------
// Setup Function
// --------------------------------------
void setup() {
  Serial.begin(9600);

  // Initialize I2C + OLED Display
  if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println("OLED allocation failed!");
    while (true); // Stop execution
  }

  Serial.println("OLED Initialized Successfully!");

  // Clear display buffer
  display.clearDisplay();

  // Display startup message
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);

  display.setCursor(32, 0);
  display.println("Arduino Nano");

  display.setCursor(35, 15);
  display.println("Welcome to");

  display.setCursor(30, 30);
  display.println("Aavishkaran");

  display.setCursor(0, 50);
  display.println("Loading...");

  display.display();
  delay(2000);

  // Run shapes demo once
  shapesDemo();
}

// --------------------------------------
// Main Loop Function
// --------------------------------------
void loop() {
  counterDemo();
}

// --------------------------------------
// Function: Counter Demo
// --------------------------------------
void counterDemo() {
  static int count = 0;

  display.clearDisplay();

  display.setTextSize(1);
  display.setCursor(0, 0);
  display.println("Counter");

  display.setCursor(0, 20);
  display.print("Count: ");
  display.println(count);

  display.setCursor(25, 45);
  display.println("Aavishkarah");

  display.display();

  count++;
  delay(1000);
}

// --------------------------------------
// Function: Shapes Demo
// --------------------------------------
void shapesDemo() {
  display.clearDisplay();

  // Draw border rectangle
  display.drawRect(0, 0, 128, 64, SSD1306_WHITE);

  // Draw filled rectangle
  display.fillRect(10, 10, 40, 20, SSD1306_WHITE);

  // Draw horizontal line
  display.drawLine(0, 35, 127, 35, SSD1306_WHITE);

  // Draw vertical line
  display.drawLine(64, 0, 64, 63, SSD1306_WHITE);

  display.setTextSize(1);
  display.setCursor(70, 10);
  display.println("Shapes");

  display.setCursor(75, 25);
  display.println("Demo");

  display.display();
  delay(3000);
}