Oled display question

Driftrotor · March 12, 2022, 2:24pm

As I’m about to get my first oled display and start messing about with it, I have been looking at various things to do with the display.
My question is, is there a way to have contrast control? Or is it just straight on off for the pixels?

mcarcher · March 12, 2022, 7:01pm

According to the datasheet, you can adjust the brightness:

Edit: this is for the display…I assume any breakout board will have resistor on it that you’d have to find.

profezzorn · March 12, 2022, 7:50pm

If I remember correctly, there is a brightness adjustment register:

github.com

profezzorn/ProffieOS/blob/2b67bd5e5ad65ee14b75f1b1bb49d96683ae1740/display/ssd1306.h#L911

    
      
              Send(SEGREMAP | 0x1);        // 0xa0 | 1
              Send(COMSCANDEC);
          #endif
          
          
    Send(SETCOMPINS);                    // 0xDA
              if (HEIGHT == 64 || WIDTH==64) {
                Send(0x12);
              } else {
                Send(0x02);  // may need to be 0x12 for some displays
              }
              Send(SETCONTRAST);                   // 0x81
              Send(0x8F);
          
          
    Send(SETPRECHARGE);                  // 0xd9
              Send(0xF1);
              Send(SETVCOMDETECT);                 // 0xDB
              Send(0x40);
              Send(DISPLAYALLON_RESUME);           // 0xA4
              Send(NORMALDISPLAY);                 // 0xA6
          
          
    Send(DEACTIVATE_SCROLL);

Driftrotor · March 12, 2022, 11:27pm

Thats good to know.
But what I was really after (sorry I don’t think I asked the right question) is, could we have some pixels fully lit while others are half lit?
Just been going over some bitmap images and some have varying degrees of brightness from the pixels so gives a nice shaded picture.

A bit like this one.

NoSloppy · March 12, 2022, 11:35pm

I don’t know if it’s possible in the future, but currently the images used with ProffieOS need to be 1bpp (bit per pixel), which means monochrome, which means only white and black.

Driftrotor · March 12, 2022, 11:36pm

Ok thank you.

profezzorn · March 13, 2022, 12:11am

The SSD1306 chip does not support this.
It may well be that other chips do.
Grayscale images will also take a lot more space, so reading from the SD card and feeding them to the display might be slow.

profezzorn · March 15, 2023, 10:08am

A post was split to a new topic: OLED not turning on without blade