How to initialize SSD1306 over i2c

[zaze06]

I have been google(I'm not good at it) on how to initialize an SSD1306 OLED display over I2C and then be able to draw a Graphics2d instance onto the display. and since the thing drawn onto the Graphics2D instance isn't displayed I suspect the initialization code to be the cause.

initialization code:

display.write((byte) 0xAE);
display.write((byte) 0xA6);
display.write((byte) 0x20, (byte) 0x00);
display.write((byte) 0x40);
display.write((byte) 0xA0);
display.write((byte) 0xC0);
display.write((byte) 0xA8, (byte) 0x3F);
display.write((byte) 0xD3, (byte) 0x00);
display.write((byte) 0xD5, (byte) 0x80);
display.write((byte) 0xD9, (byte) 0x22);
display.write((byte) 0xDA, (byte) 0x12);
display.write((byte) 0xDB, (byte) 0x20);
display.write((byte) 0x8D, (byte) 0x14);

code to send the data of the Graphics2D instance to the display:

byte[][] pixels = new byte[getHeight()][getWidth()];

for(int y = 0; y < getHeight(); y++){
    for(int x = 0; x < getWidth(); x++){
        try {
            pixels[y][x] = pixelToByte(img.getRGB(x, y));
        }catch (Exception e){
            int i = 0;
        }
    }
}
for (int row = 0; row < getHeight(); row++) {
    display.write(0xB0 + row);
    display.write(0x00);
    display.write(0x10);
    display.write(pixels[row]);
}

Extra context:

public int getHeight(){
    return 64;
}

public int getWidth(){
    return 128;
}

private static byte pixelToByte(int rgb) {
    int alpha = (rgb >> 24) & 0xFF;
    int red = (rgb >> 16) & 0xFF;
    int green = (rgb >> 8) & 0xFF;
    int blue = rgb & 0xFF;
    byte pixelData;
    if (alpha > 0 && (red > 0 || green > 0 || blue > 0)) {
        pixelData = 1;
    } else {
        pixelData = 0;
    }
    return pixelData;
}

I'm not the best coder and I'm unsure of if the values are correct or not. thanks for any help provided

I excuse my poor grammar. English isn't my first language and I have dyslexia

[zaze06]

So after posting this I did see the

try {
    pixels[y][x] = pixelToByte(img.getRGB(x, y));
}catch (Exception e){
    int i = 0;
}

and I changed that out a bit and no I do not get anything there

[taartspi]

SSD1306_Example.java.zip

I used a HiLetgo SSD1306 The attached zip initializes the chip and places a line of pixels on the display. Hopefully you can review what I have a see what changes are required in your code.
When I have time I will write a better example of pixel placement, make this a module and add it to my github repo.

[taartspi]

SSD1306_Example.java.zip
Update to zip file.

Still sorting out putting complete patterns into the display, not sure if some init change will be required or just proper code to complete the RAM update.

[taartspi]

I completed an example SSD1306 Vertical address mode. It is in https://github.com/Pi4J/pi4j-example-devices

Hope this helps if you have remaining questions on your project. Tom

[zaze06]

Thanks, I will take a look at it

[zaze06]

So now when i have revisited this project I checked out the example for the SSD1306 display and copied the classes required for it to not give me compilation errors and copid some code from the examples class. I get an image displayed but its just jibrish on the display, and I suspect it to be caused by the BufferdImage to Byte array method I have (provided bellow) and if that is the case how should it be made to display the correct data stored I the BufferdImage object?

private static void dataToBuffer(BufferedImage img) {
        for(int x = 0; x < getWidth(); x++){
            for(int y = 0; y < getHeight(); y++){
                if(
                        (float) ((0.3*(
                                new Color(
                                        img.getRGB(x,y)
                                ).getRed()
                        )+0.59*(
                                new Color(
                                        img.getRGB(x,y)
                                ).getGreen()
                        )+0.11*(
                                new Color(
                                        img.getRGB(x,y)
                                ).getBlue()
                        ))/255) >= 0.5
                ){
                    buffer[x + (y / 8) * getWidth()] |= (1 << (y & 7));
                }else{
                    buffer[x + (y / 8) * getWidth()] &= ~(1 << (y & 7));
                }
            }
        }
    }

all the data to the display is handled by the SSD1306 class defined in the github repo you provided

[zaze06]

Ok, so I fixed it whit this method instead (provided below) and changed the address mode to horizontal instead of vertical. now the only problem is that the image is upside down but that should be easier to fix.

private static void dataToBuffer(BufferedImage img) {
        for(int x = 0; x < 128; x++){
            for(int y = 0; y < 64; y++){
                if(img.getRGB(x,y) == Color.BLACK.getRGB()){
                    buffer[x + (y / 8) * getWidth()] &= ~(1 << (y & 7));
                }else{
                    buffer[x + (y / 8) * getWidth()] |= (1 << (y & 7));
                }
            }
        }
    }

[zaze06]

fixed the rotation by fliping the image before displaying

[FDelporte]

Hi @zaze06, very interested in the result of this project!
Are you willing to share a video and the code, or even contribute it to the Pi4J website?

[zaze06]

what other video were you thinking of in that case? but I did find way the buttons weren't working, I didn't read the correct pins I think

[FDelporte]

sorry, thought you were trying to do something via the digital input ;-) wrong conclusion

[FDelporte]

anyhow not urgent, whenever you have time and are happy with the result of your project

[zaze06]

Well I'm using the digital input for the program whit buttons and I'm currently having issues whit reading the GPIO pins, and without it there isn't much the program can do.

[zaze06]

anyhow not urgent, whenever you have time and are happy with the result of your project

Thanks, but hear is a GitHub repo of the code. It's semi-functional, as in you cant interact whit it.
And the setup instructions will soon be added to the README

https://github.com/zaze06/menue