// XIAO ESP32-C3 & SSD1306 0,96 Display NONAME
// very impotend !!! bevor upload , boot set , reset set, sound lisen ,rest release , sound lisen , boot release   
#include <Arduino.h>
#include <U8g2lib.h>

#define SDA_PIN D4
#define SCL_PIN D5

//U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE, /* clock=*/ SCL_PIN, /* data=*/ SDA_PIN);   // ESP32 Thing, HW I2C with pin remapping
// no d10 blink , no sda , no scl , no display

U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /*clock=*/ SCL_PIN, /* data=*/ SDA_PIN, /* reset=*/ U8X8_PIN_NONE);
// no d10 blink , no sda , no scl , no display

//U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL_PIN, /* data=*/ SDA_PIN, /* reset=*/ U8X8_PIN_NONE);   // ESP32 Thing, pure SW emulated I2C
// ja d10 blinkt , ja sda , ja scl , display " Hello World " okay , refresh 500ms

void setup() {
u8g2.setBusClock(200000);
 // Wire.begin(SDA_PIN, SCL_PIN);
  u8g2.begin();  

//pinMode(D4, OUTPUT);//sda
//pinMode(D5, OUTPUT);//scl
pinMode(D10, OUTPUT);//LED for work test
}//end setup

void loop() {
digitalWrite(D10, LOW);  
//  delay(100);
  u8g2.clearBuffer();          // clear the internal memory
  u8g2.setFont(u8g2_font_ncenB08_tr); // choose a suitable font
  u8g2.drawStr(0,10,"Hello 3. World!");  // write something to the internal memory
  u8g2.sendBuffer();          // transfer internal memory to the display
digitalWrite(D10, HIGH);  
  delay(1000);   
}//end loop