Use the K2 LCD

The LCD is part of the F256K2 enclosure

The LCD embedded in the enclosure is Sitronix ST7789. The full resolution is 240 pixels wide, 320 pixels high. However, there's a 20 pixel high band at the top and a 20 pixel high band at the bottom which are covered, so the visible usable part is 240x280.

Registers

Register Name	Address	Description
LCD_CMD_CMD	0xDD40	Write Command Here
LCD_CMD_DTA	0xDD41	Write Data (For Command) Here; Always Write in pairs (to LCD_PIX_LO and LCD_PIX_HI), otherwise the State Machine will Lock
LCD_PIX_LO	0xDD42	{G[2:0], B[4:0]}
LCD_PIX_HI	0xDD43	{R[4:0], G[5:3]}

Commands for LCD_CMD_CMD

Command Name	Value	Description
LCD_RST	0x10	0 to Reset (RSTn)
LCD_BL	0x20	1 = ON, 0 = OFF
LCD_WIN_X	0x2A	define window X
LCD_WIN_Y	0x2B	define window Y
LCD_WRI	0x2C	{R[4:0], G[5:3]}

Compatible image format

You can send in a .bmp image exported in R5 G6 B5 color palette, converted into a raw 2 byte/per/pixel binary file. The R5 G6 B5 palette expects color information in this format:

High byte__ Low byte

RRRRRGGG GGGBBBBBB

The process goes as:

1) Use gimp (or equivalent alternative) and export your image as 'Windows BMP Image', but go to advanced options

2) select 16 bit, R5 G6 B5 for the color

3) run my python script to convert it to a raw binary found at https://github.com/Mu0n/F256MiscGoodies/tree/main in /tools/

4) for every pixel, send 2 bytes of data to the LCD_PIX_LO and LCD_PIX_HI registers found in the table above

5) you can find some example code from my C github repo here, which sends an image to the LCD screen and then idles.