Arduino Nano + SSD1306

[vasquez77]

Hello everyone...

I'm completely running out of control...
Just so easy to connect to an Oled-Display via I²C (SSD1306 / 128x32), but i still can't get it running.

Connection SDA --> A4, SCL --> A5, GND--> GND, VCC-->+5V
I'am using the sample from the Adafruit SSD1306 lib (ssd1306_128x32_I²C).

I run an I²C adress-finder, which found 0X3C.
I put this adress to:

if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { // Address 0x3C for 128x32
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }

Programm seems to work, because at the end of the sample code, the serial terminal throws the x- and y-positions...

The display ist still dark - it's not possible to see anything.
I checked the 5 to 3,3V regulator on the display and it's working.

I set a different adress (from 0X3C to 0x3D, or 0X3E) and in this case, the x- and y-positions were also displayed in the terminal...this is strange for me, because the adress should be 0X3C ???
The code should generate a failure, like:

Serial.println(F("SSD1306 allocation failed"));

However, i also played with this parameter (think it should be -1 for only SDA/SCL):

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)

Does anyone has an idea, why the display is still dark ?
Grettings...

[xfpd]

You need display.display(); to make your display.println(); show anything on the OLED.

[edit]

display.println("¡Ola, Mundo!");
display.display();

[vasquez77]

Yes, thanks.
I know, that the display buffer has to be sent by a spereate command.

Now i found the problem - it's up to the display.
I bought 10 over the I-Net ---> 8 of them are broken, so the internal controller is running, but the
display itself seems to be broken...

So the example - code for the SSD1306 seems to be ok...