STM32 LTDC Simple Text String Output to LCD

[PFlor.2]

I have successfully setup the LTDC to work with my LCD to display TouchGFX images with no problems. However, I am also developing a simple bootloader for USB software updates that I need to display text to the display without the use of RTOS or TouchGFX. Anyone have an example of how to achieve this with the STM32 LTDC?

[KDJEM.1]

Hello @PFlor.2​ ,

Could you precise the STM32 product you are using?

I recommend you to get inspired from the BSP example.

This example based on STM32F769I-EVAL and described how to display text.

I hope this help you!

When your question is answered, please close this topic by choosing Select as Best. This will help other users find that answer faster.

Kaouthar 

[Tesla DeLorean · Accepted solution]

Several examples out there with text, circle, and line drawing primitives

STM32Cube_FW_H7_V1.9.1\Projects\STM32H743I-EVAL\Applications\Display\LTDC_Paint\Src\main.c

STM32Cube_FW_H7_V1.9.1\Projects\STM32H743I-EVAL\Examples\JPEG\JPEG_DecodingFromFLASH_DMA\Src\main.c

[PFlor.2]

Thanks for the tip, I had actually found the LTDC_Paint example and was able to incorporate portions of that example in order to write text to the display! Do you know how the frame buffer works. I use the UTIL_LCD_DisplayStringAtLine() function to display text. However, once at the bottom of the screen I would like to scroll all previous line up one line to make room for the next line of text. How could this be done with the frame buffer to achieve this scrolling??

[PFlor.2]

Thanks for the tip, I had actually found the LTDC_Paint example and was able to incorporate portions of that example in order to write text to the display! Do you know how the frame buffer works. I use the UTIL_LCD_DisplayStringAtLine() function to display text. However, once at the bottom of the screen I would like to scroll all previous line up one line to make room for the next line of text. How could this be done with the frame buffer to achieve this scrolling??

[Tesla DeLorean]

The Frame Buffer is a pretty typical line raster format.

Text is constructed from a font bitmap table.

Scrolling is achieved via a memcpy() pulling one or more raster lines forward.

Hardware scroll via a longer buffer, and advancing the start point to the LTDC