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

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

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
// The pins for I2C are defined by the Wire-library. 
// On an arduino UNO:       A4(SDA), A5(SCL)
// On an arduino MEGA 2560: 20(SDA), 21(SCL)
// On an arduino LEONARDO:   2(SDA),  3(SCL), ...
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define BUTTON_A 2
#define BUTTON_B 3
#define LED 13

int a_last = 0;
int a_curr = 0;

int b_last = 0;
int b_curr = 0;

unsigned int counter = 0;

void graphicsUpdate();

void setup() {
  // put your setup code here, to run once:
  // set up pin mode for both buttons
  pinMode(BUTTON_A, INPUT);
  pinMode(BUTTON_B, INPUT);
  // set pin mode for LED
  pinMode(LED, OUTPUT);
  
  // some info will be sent to serial
  Serial.begin(9600);

  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

  // set up for text
  display.setTextColor(SSD1306_WHITE);
  display.setTextSize(2);

  display.display();
}

void loop() {
  // A button check
  a_curr = digitalRead(BUTTON_A);

  if (a_curr != a_last)
  {
    // if has changed, increment counter
    if (a_curr == LOW) // button just went from off to on
    {
      counter++;
      Serial.println(counter);
      delay(50);
    }
    a_last = a_curr;

  /*
    if (counter % 4 == 0)
    {
     Serial.println("Pressed");
     digitalWrite(LED, HIGH);
    }
    else
    {
      digitalWrite(LED, LOW);
    }
  */
  }

  // B button check
  b_curr = digitalRead(BUTTON_B);

  if (b_curr != b_last)
  {
    // if has changed, increment counter
    if (b_curr == LOW) // button just went from off to on
    {
      counter--;
      Serial.println(counter);
      delay(50);
    }
    b_last = b_curr;

  /*
    if (counter % 4 == 0)
    {
     Serial.println("Pressed");
     digitalWrite(LED, HIGH);
    }
    else
    {
      digitalWrite(LED, LOW);
    }
  */
  }

  graphicsUpdate();
}

void graphicsUpdate()
{

  display.clearDisplay();
  display.setCursor(0, 0);

  display.print("DEC:");
  display.println(counter);

  display.print("BIN:");
  display.println(String(counter, BIN));
  
  
  display.print("HEX:");
  display.println(String(counter, HEX));

  display.print("OCT:");
  display.println(String(counter, OCT));
  display.display();

}