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

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

// create an OLED display object connected to I2C
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);





#include <Keypad.h>

const byte ROWS = 3;
const byte COLS = 3;

char keys[ROWS][COLS] = {
  {'A','B','C'},
  {'<', '^','D'},
  {'_','X','>'}
};

byte rowPins[ROWS] = {6, 5, 4}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {7, 15, 16}; //connect to the column pinouts of the keypad


//Create an object of keypad
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );




void setup() {
  Serial.begin(9600);

  // initialize OLED display with I2C address 0x3C
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("failed to start SSD1306 OLED"));
    while (1);
  }

  delay(2000);         // wait two seconds for initializing
  oled.clearDisplay(); // clear display

  oled.setTextSize(2);         // set text size
  oled.setTextColor(WHITE);    // set text color
  oled.setCursor(5, 25);       // set position to display (x,y)
  oled.println("Heart Beat"); // set text
  oled.display();              // display on OLED
}


  
void loop(){
  char key = keypad.getKey();// Read the key
  
  // Print if key pressed
  if (key){
    Serial.print("Key Pressed : ");
    Serial.println(key);

    oled.clearDisplay(); // clear display
    oled.setTextSize(3);         // set text size
    oled.setTextColor(WHITE);    // set text color
    oled.setCursor(50, 20);       // set position to display (x,y)
    oled.println(key); // set text
    oled.display();  
  }
}