OLED Display 1.3"
SH1106 Setup Guide

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

// SH1106 · 128×64 · I2C · Full framebuffer
U8G2_SH1106_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, U8X8_PIN_NONE);

void setup() {
  u8g2.begin();

  u8g2.clearBuffer();

  // Draw border
  u8g2.drawFrame(0, 0, 128, 64);

  // Large title
  u8g2.setFont(u8g2_font_logisoso16_tr);
  u8g2.drawStr(22, 28, "TISHVI");

  // Subtitle
  u8g2.setFont(u8g2_font_6x10_tr);
  u8g2.drawStr(14, 44, "1.3\" OLED Ready!");
  u8g2.drawStr(10, 58, "guide.tishvi.com");

  u8g2.sendBuffer();   // Push to display
}

void loop() {
  // Message stays — nothing in loop
}

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

U8G2_SH1106_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, U8X8_PIN_NONE);

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

void loop() {
  unsigned long t = millis() / 1000;
  int h = t / 3600;
  int m = (t % 3600) / 60;
  int s = t % 60;

  char buf[9];
  sprintf(buf, "%02d:%02d:%02d", h, m, s);

  u8g2.clearBuffer();

  // Header
  u8g2.setFont(u8g2_font_6x10_tr);
  u8g2.drawStr(10, 10, "Tishvi SH1106 Demo");
  u8g2.drawHLine(0, 13, 128);

  // Label
  u8g2.drawStr(0, 28, "Uptime:");

  // Large time display
  u8g2.setFont(u8g2_font_logisoso16_tr);
  u8g2.drawStr(4, 50, buf);

  u8g2.sendBuffer();
  delay(1000);
}