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

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

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

int radius = 7;
int change = 2;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("failed to start SSD1306 display"));
    while (1);
  }

  display.setCursor(0,0);
}

void loop() {
  //face
  display.clearDisplay();
  display.drawCircle(50, 30, 30, WHITE);

  display.drawCircle(33, 20, 5, WHITE);

  display.drawCircle(67, 20, 5, WHITE);

  display.drawCircle(50, 45, radius, WHITE);

  delay(10);

  if(radius < 4){
    change = 1;
  }

  else if(radius > 7){
    change = 2;
  }

  if( change == 1){
    radius++;
  }

  if( change == 2){
    radius--;
  }
  display.display();

}