Bitmap2LCD is a universal programming tool for converting bitmaps/images to GLCD for most graphic LCD controllers.
This software tool can be used for programming embedded systems connected to a Grayscale Small Graphic LCD ( OLED ) with a built-in COG LCD controller similar to the ST7528.
For a start, here’s a short article about 4bpp grayscale (4-bits per pixel ) for displaying 16 levels of gray.
The values from 0 through 15 decimal (00 to 0F hex) correspond to lightest (white) through darkest (black) as shown in the representation below.
A single byte in the DDRAM can be used to store 2 pixels of information.
When using a module with an on glass ST7528 LCD controller, in the source code data byte, the first pixel data comes after the second pixel data : 22221111
With bitmap2LCD [from v2.0 upwards] you can set ON the automatic pixel data nibble swapping, for a correct ordering in the source code output.