#include <Adafruit_SSD1306.h> // changed display library
Adafruit_SSD1306 display = Adafruit_SSD1306(128, 64, &Wire, -1); // updated to SSD1306

int exampleVariable = 20;

int numberCounter = 0;

void setup() {

  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);

  display.setTextColor(SSD1306_WHITE); // changed color constant to SSD1306

}

void loop() {

  display.clearDisplay(); //reset to a blank screen 
  //display.invertDisplay(true); //remove comment slashes to invert screen 
  display.drawLine(40, 40, 80, 40, SSD1306_WHITE); //draws a line 
  display.fillRect(10, 20, 10, 10, SSD1306_WHITE); //draws a rectangle 
  display.drawCircle(40, 30, 6, SSD1306_WHITE); //draws a circle 
  display.drawPixel(100, 10, SSD1306_WHITE); //turn on a single pixel 

  display.setTextSize(1); //change text size 
  display.setCursor(5, 45); //move cursor origin point 
  display.print(exampleVariable); //print the value of a variable which was initialized at the top 
  display.print(" example "); //print text 
  display.print(millis()); //print the number of milliseconds since the start 
  display.print(" "); //print a space 
  display.print(numberCounter); //print the value of a variable 
  numberCounter++; //plus 1 to the variable 
  delay(500); //add a delay for the rest of the code to run 
  display.display(); //display the code 
}