I2C Module Problems with Grove Beginner Kit for Arduino

Jens · June 10, 2020, 8:26pm

Back to the OLED Problem.

Mayby it has also something to do with the 3-Axis module.

HW I2C for the OLED works ony when the 3-Axis module is also connected.

I used the following sketch to proof it:

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

#ifdef U8X8_HAVE_HW_SPI
#include <SPI.h> 
#endif
#ifdef U8X8_HAVE_HW_I2C
#include <Wire.h>
#endif


// works only whenn the 3-Axis Module is also connected. If the 3-Axis Modul is not connected the Display keeps black
U8G2_SSD1306_128X64_NONAME_F_HW_I2C u8g2(U8G2_R0, /* reset=*/U8X8_PIN_NONE); 

// SW I2C works allways 
//U8G2_SSD1306_128X64_NONAME_F_SW_I2C u8g2(U8G2_R0, /* clock=*/ SCL, /* data=*/ SDA, /* reset=*/ U8X8_PIN_NONE);

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

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

The Setup