// Using this code, you can display the text of your choice on the OLED and also
// control the position of the text displayed using the push-buttons in the order
// arranged. You may also use the arrow buttons on your keyboard for the same
// functionality. 

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

#define SCREEN_WIDTH 128 
#define SCREEN_HEIGHT 64 
#define OLED_RESET -1  
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define BUTTON_UP 23    
#define BUTTON_DOWN 25  
#define BUTTON_LEFT 26  
#define BUTTON_RIGHT 27  

int8_t displayOffsetX = 0;
int8_t displayOffsetY = 0;
const uint8_t textSize = 1;

String userInput; // This will hold the user input

void setup() {
  Serial.begin(9600); // Start the serial communication with the baud rate of 9600
  while (!Serial) {
    ; // Wait for serial port to connect. Needed for native USB port only
  }

  Serial.println("Enter text to be displayed:");

  pinMode(BUTTON_UP, INPUT_PULLUP);
  pinMode(BUTTON_DOWN, INPUT_PULLUP);
  pinMode(BUTTON_LEFT, INPUT_PULLUP);
  pinMode(BUTTON_RIGHT, INPUT_PULLUP);

  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;)
      ;
  }

  display.display();
  delay(2000);

  display.clearDisplay();
  display.setTextColor(SSD1306_WHITE);
  display.setTextSize(textSize);
  display.setCursor(0, 0);
  display.println(userInput);
  display.display();
}

void loop() {
  while (Serial.available()) { // Check if data is available to read
    userInput = Serial.readString(); // Read the input string
    display.clearDisplay();
    display.setCursor(displayOffsetX * textSize, displayOffsetY * textSize);
    display.println(userInput);
    display.display();
  }

  if (digitalRead(BUTTON_UP) == LOW) {
    // Scroll display up
    displayOffsetY++;
    display.clearDisplay();
    display.setCursor(displayOffsetX * textSize, displayOffsetY * textSize);
    display.println(userInput);
    display.display();
    delay(100);
  }

  if (digitalRead(BUTTON_DOWN) == LOW) {
    // Scroll display down
    displayOffsetY--;
    display.clearDisplay();
    display.setCursor(displayOffsetX * textSize, displayOffsetY * textSize);
    display.println(userInput);
    display.display();
    delay(100);
  }

  if (digitalRead(BUTTON_LEFT) == LOW) {
    // Scroll display left
    displayOffsetX--;
    display.clearDisplay();
    display.setCursor(displayOffsetX * textSize, displayOffsetY * textSize);
    display.println(userInput);
    display.display();
    delay(100);
  }

    if (digitalRead(BUTTON_RIGHT) == LOW) {
    // Scroll display right
    displayOffsetX++;
    display.clearDisplay();
    display.setCursor(displayOffsetX * textSize, displayOffsetY * textSize);
    display.println(userInput);
    display.display();
    delay(100);
  }
}