#include <Arduino.h>
#include <U8g2lib.h>
#include <qrcode.h>

// Setup u8g2 library for SSD1306 OLED
U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);

// Create a QR code object
QRCode qrcode;

void setup() {
  u8g2.begin();
}

void loop() {
  u8g2.clearBuffer(); // Clear the internal memory

  // Create a string for the QR code
  String str = "Hello World";

  // Create a char array from the string
  char charBuf[str.length() + 1];
  str.toCharArray(charBuf, str.length() + 1);

  // Generate the QR code
  uint8_t qrcodeData[qrcode_getBufferSize(3)];
  qrcode_initText(&qrcode, qrcodeData, 3, 0, charBuf);

  // Draw the QR code on the OLED
  for (uint8_t y = 0; y < qrcode.size; y++) {
    for (uint8_t x = 0; x < qrcode.size; x++) {
      if (qrcode_getModule(&qrcode, x, y)) {
        u8g2.drawBox(x*2, y*2, 2, 2);
      }
    }
  }

  u8g2.sendBuffer(); // Transfer internal memory to the display
  delay(5000); // Wait for 5 seconds
}