Lvgl8.x migrating to stm32f4

1. Requirements for chips

• processor 16,32 or 64 Bit microcontroller or processor
• The clock frequency is the lowest 16 MHz clock frequency
• Flash/ROM For very important components, it is required to be greater than 64 kB ( The suggestion is greater than 180 kB)
• RAM static state RAM Usage approx 2 kB, Depending on the function and object type used
  Stack ： Greater than 2kB ( The suggestion is greater than 8 kB)
  Dynamic data ( Pile up )： Greater than 2 KB( If you use multiple objects , It is suggested to be greater than 16 kB). from lv_conf.h Medium LV_MEM_SIZE Macro settings
  Show buffer ： Pixels larger than horizontal resolution ( The suggestion is greater than 10 Row horizontal resolution ),MCU Or a frame buffer in an external display controller
• The compiler must support C99 Or later compilers
• The technology stack has basic C ( or C ++) knowledge ： The pointer , structure , Callback

2. Download source package

You need to download the source code package before porting , The source code package can be created by using GitHub Clone or download , stay Github Mid search lvgl You can search for lvgl The official warehouse of , Enter the official warehouse to use git Clone to local computer , Or click download directly to download the entire source package to the local computer .

3. Overview source directory

The main applications are ：examples/,src/,lv_conf_template.h,lvgl.h. Respectively lvgl Routine folder , Source folder ,lvgl Profile templates ,lvgl Main header file .

3.1. src Source directory

core Core source code
draw Drawing source code
extra For additional functions , Some advanced interface implementations

font Built in Fonts
gpu GPU Drive implementation , This needs to be supported by the chip used
hal Hardware abstraction layer
misc miscellaneous
widget Basic interface components

3.2. examples Routine Directory

anim Animation usage routines
arduino Support arduino Configuration file for , Generally not used , Unless used arduino
assets Code or image array of some small components , In order to know the style generated by the code, the corresponding style pictures are also provided
event some lvgl Event writing and using routines
get_started Component usage routines
layouts lvgl Layout usage routines
porting lvgl Drive docking method template
scroll lvgl Scrolling using routines
styles Component style usage routines
widgets The same is lvgl Component usage routines
In general, this folder is just as the name suggests for some use of reference code , If you want to quickly view the effect, you can copy and use the code here to generate View the required components , This directory is commonly used .

4. stm32 Formwork works

transplant lvgl Before that, we need to build a compiler stm32 Code compilation project , Used to compile stm32 Relevant code files （ For example, common Keil-MDK engineering ）. For the development of man-machine interface, it is also necessary to prepare a display screen （ As for any kind of display screen ,lvgl The inside doesn't care what kind of screen you use ）, And use stm32 To drive it . As for how to build stm32 Compilation engineering is not introduced here , Because it mainly explains how to lvgl Migration to stm32, At the same time, I believe that I must know how to build it if I can see here stm32 The compilation project of .

Be careful ： here keil Version USES keil5.26
STM32 Use STM32F407VET6, Of course, this migration method is not only applicable to STM32F407VET6,stm32 Series single chip microcomputer or other types of single chip microcomputer are applicable .

5. Start migration

5.1 Prune unneeded folders and files

Unzip the previously downloaded lvgl The source code package can get a lvgl-8.0.2 Folder , leave lvgl-8.0.2/examples/ Folder ,lvgl-8.0.2/src/ Folder ,lvgl-8.0.2/LICENCE.txt file ,lvgl-8.0.2/lv_conf_template.h file ,lvgl-8.0.2/lvgl.h file ,lvgl-8.0.2/README.md file , The rest can be deleted .
At the same time lvgl-8.0.2/examples/porting The folder is cut to the upper directory （ namely lvgl-8.0.2/）, Finally, as shown in the figure below

5.2 Rename file

take lvgl-8.0.2/lv_conf_template.h Change the document to lv_conf.h,（ The configuration file ）
take lvgl-8.0.2/porting/lv_port_disp_template.c Change the document to lv_port_disp.c （ Show related ）
take lvgl-8.0.2/porting/lv_port_disp_template.h Change the document to lv_port_disp.h（ Show related ）
take lvgl-8.0.2/porting/lv_port_fs_template.c Change the document to lv_port_fs.c（ File system related ）
take lvgl-8.0.2/porting/lv_port_fs_template.c Change the document to lv_port_fs.h（ File system related ）
take lvgl-8.0.2/porting/lv_port_indev_template.c Change the document to lv_port_indev.c（ Input device related ）
take lvgl-8.0.2/porting/lv_port_indev_template.c Change the document to lv_port_indev.c（ Input device related ）

6. add to lvgl File to keil5

6.1 add to lvgl Source code

add to lvgl-8.0.2/src/core All under directory c file
add to lvgl-8.0.2/src/draw All under directory c file
add to lvgl-8.0.2/src/extra All under directory c file
add to lvgl-8.0.2/src/font All under directory c file
add to lvgl-8.0.2/src/gpu All under directory c file
add to lvgl-8.0.2/src/hal All under directory c file
add to lvgl-8.0.2/src/misc All under directory c file
add to lvgl-8.0.2/src/widgets All under directory c file

add to lvgl-8.0.2/porting/lv_port_disp.c , Because only the display effect after successful migration can be viewed here , Therefore, only display related device interface files are added here .

6.2 add to lvgl Source file path

The following header file paths need to be added
lvgl8.0.2/
lvgl8.0.2/src
lvgl8.0.2/porting

Detailed view ：https://cloud.tencent.com/developer/article/1862110

7. modify lv_conf.h

take lvgl Configure the... Of the header file Conditional compilation is set to 1, Enable configuration .

8. modify stm32 Stack size

open stm32 To modify the startup file , Here's the picture

9. keil c99 Pattern

Follow the steps shown in the figure below to keil5 Set to c99 Pattern .

10. Interface with screen drawing

See the following articles for details of this section lvgl8.0 Docking screen drivers This part .