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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

Adafruit_SSD1306 display(SCREEN_WIDTH,SCREEN_HEIGHT, &Wire ,-1);

int mouth_radius= 5;
int change = 1;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  
  if(!display.begin(SSD1306_SWITCHCAPVCC,0x3C)){
    Serial.println("Failed");
    while(1);
  }
  display.clearDisplay();
}

void loop() {
  // put your main code here, to run repeatedly:
  display.clearDisplay();
  
  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(2,SCREEN_HEIGHT /2);
  display.println("WOW");
  display.display();
  delay(50);// this speeds up the simulation
  if(mouth_radius == 15)
  {
    change = -1;
    delay(500);
  }
  else if (mouth_radius  ==  5)
  {
    change = 1;
    delay(500);
  }

  //  change the mouth radius
  mouth_radius = mouth_radius + change;
  
}