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

#define SCREEN_WIDTH 128 
#define SCREEN_HEIGHT 64 

String a="";

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

void setup() {
  pinMode(11, OUTPUT);
  
  Serial.begin(9600);

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



void loop() {
  if (Serial.available()){
    
    a=Serial.readString();
    Serial.println(a);
    if (a=="hello\n"){
      Serial.println("yess");
      oled.clearDisplay();
      oled.setTextSize(2);
      oled.setTextColor(WHITE);
      oled.setCursor(0, 10);
      oled.print("hello!"); 
      oled.display();
    }

    if (a=="how are you?\n"){
      oled.clearDisplay();
      oled.setTextSize(2);
      oled.setTextColor(WHITE);
      oled.setCursor(0, 10);
      oled.print("fine! how r u?"); 
      oled.display();
    }
    if (a=="fine too\n"){
      Serial.println("yess");
      oled.clearDisplay();
      oled.setTextSize(2);
      oled.setTextColor(WHITE);
      oled.setCursor(0, 10);
      oled.print("great!"); 
      oled.display();
    }
  }
}