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

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
#define SCREEN_ADDRESS 0x3C

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

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

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

  delay(2000);
  display.clearDisplay();
}

void loop() {
  String text_to_scroll = "Chinesium     ";
  int buffer_size = SCREEN_WIDTH * 2;
  String buffer_text = "";
  for (int i = 0; i < buffer_size / text_to_scroll.length(); i++) {
    buffer_text += text_to_scroll;
  }

  while(true) {
    for(int i = 0; i < buffer_text.length() - SCREEN_WIDTH; i++) {
      display.clearDisplay();

      display.setTextSize(8);           
      display.setTextColor(SSD1306_WHITE);  
      display.setCursor(0, 0);     
      display.print(buffer_text.substring(i, i + SCREEN_WIDTH));
      display.display();  
      
      delay(100);  
    }
  }
}