#include <SPI.h>
#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

#define OLED_RESET -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display (SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET); // create an object/instance of Adafruit_SSD1406

void setup() {
  Serial.begin(115200); // start Serial Monitor

  // initialize OLED
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) // OLED address
  { Serial.println(F("SSD1306 allocation failed"));
    while (1);
  } // OLED init failed. HALT.

  display.clearDisplay(); // 

  display.setTextSize(1); // text size
  display.setTextColor(WHITE); // text color
  display.setCursor(0, 0); // cursor location

  display.println("Hello, World!");
  display.print("\n\nNumber overwritten \nin black");
 
  display.display(); // this must be called to display the buffer
}

void loop() {
  int i;
  for (i = 0; i < 9; i++)
  {
    display.setTextColor(WHITE); // draw with white
    display.setCursor(50, 32);
    display.print(i);
    display.display();
    delay(1000);
    display.setTextColor(BLACK); // erase with black
    display.setCursor(50, 32);
    display.print(i);
    display.display();
  }
}

/*
    More OLED functions:

    display.clearDisplay() // all pixels off

    display.setTextColor(WHITE); // text color
    display.setTextSize(n) // set the font size 1 to 8
    display.setCursor(x,y) // set the coordinates to start writing text
    display.print(“message”) // print the characters at location x,y

    display.drawPixel(x,y, WHITE) // plot a pixel in the x,y coordinates
    display.drawLine(x1, y1, x2, y2, WHITE) // draw line from x1,y1 to x2,y2, WHITE
    display.drawRect(x, y, width, height, WHITE) // draw a rectangle origin at x,y
    display.drawTriangle(x1, y1, x2, y2, x3, y3, color)
    display.drawCircle(x, y, radius, color

    display.display() // MUST call this method for the changes to take effect

    Convert image to bitmap for OLED
    https://sourceforge.net/projects/lcd-image-converter/files/
*/