GUI_MEMDEV_create() problem

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  • GUI_MEMDEV_create() problem

    Hello,
    To develop without flickering, I want to use GUI_MEMDEV_create() function. I get an error during creation of it. (return 0)

    To begin I used a demo code and It works very well. Layers are displayed only during the CopyToLCD functions.

    C Source Code

    1. //first memory device on layer 0: these operations are not shown
    2. //but only because there's opaque layer 1 covering them
    3. GUI_SelectLayer(0);
    4. hMem0 = GUI_MEMDEV_Create(0, 0, 200, 100);
    6. //memdev selection
    7. GUI_MEMDEV_Select(hMem0);
    8. GUI_Clear();
    9. GUI_SetColor(GUI_RED);
    10. GUI_FillRect(0, 0, 199, 33);
    11. GUI_SetColor(GUI_GREEN);
    12. GUI_FillRect(0, 34, 199, 66);
    13. GUI_SetColor(GUI_BLUE);
    14. GUI_FillRect(0, 67, 199, 99);
    16. //second memory device on layer 1: these operations are shown suddently
    17. GUI_SelectLayer(1);
    18. hMem1 = GUI_MEMDEV_Create(0, 0, 200, 100);
    20. GUI_MEMDEV_Select(hMem1);
    21. GUI_SetBkColor(GUI_WHITE);
    22. GUI_Clear();
    23. GUI_SetColor(GUI_BLACK);
    24. GUI_DispStringHCenterAt("Layer 1", 100, 4);
    25. GUI_SetColor(GUI_TRANSPARENT);
    26. GUI_FillCircle(100, 50, 35);
    27. GUI_FillRect(10, 10, 40, 90);
    28. GUI_FillRect(160, 10, 190, 90);
    30. //memory devices copy in respective layers: this is unuseful
    31. //because all is already drawn on layers
    32. //I would like to see result only after these two steps
    33. GUI_MEMDEV_CopyToLCD(hMem1);
    34. GUI_MEMDEV_CopyToLCD(hMem0);
    Display All


    Now I would like apply the same strategy to my screen (7": 800*480 pixels)
    hMem0 and hMem1 return 0. Memory are not created and all operations are shown before the CopyToLCD operation.

    C Source Code

    1. GUI_SelectLayer(0);
    2. hMem0 = GUI_MEMDEV_Create(0, 0, 800, 480);
    4. GUI_MEMDEV_Select(hMem0);
    5. GUI_Clear();
    6. GUI_SetColor(GUI_RED);
    7. GUI_FillRect(0, 0, 400, 240);
    8. GUI_SetColor(GUI_GREEN);
    9. GUI_FillRect(0, 240, 400, 480);
    10. GUI_SetColor(GUI_BLUE);
    11. GUI_FillRect(400, 0, 800, 240);
    13. GUI_SelectLayer(1);
    14. hMem1 = GUI_MEMDEV_Create(0, 0, 800, 480);
    16. GUI_MEMDEV_Select(hMem1);
    17. GUI_SetBkColor(GUI_WHITE);
    18. GUI_Clear();
    19. GUI_SetColor(GUI_DARKBLUE);
    20. GUI_DispStringHCenterAt("TEST Layer 1", 100, 4);
    21. GUI_SetColor(GUI_TRANSPARENT);
    22. GUI_AA_FillCircle(400, 240, 150);
    23. GUI_FillRect(180, 0, 220, 480);
    24. GUI_FillRect(580, 0, 620, 480);
    26. GUI_MEMDEV_CopyToLCD(hMem0);
    27. GUI_MEMDEV_CopyToLCD(hMem1);
    Display All



    Do you have an idea ? For information I use the STM32f429 discovery demo board.
    Must I increase the RAM data space ? How ?

    Thanks in advance.

  • Hello,

    Yes, the most likely reason for a creation function (in general) to return with 0 is lack of memory. Please try assigning more memory to emWin in the function GUI_X_Config() (GUIConf.c). Details about the memory requirements can be found in the chapter "Memory Devices" in the emWin user manual.

    Best regards,
    Adrian

  • Ok thank you ! It works !

    I post my source code compatible with IAR compiler:

    C Source Code

    1. #define GUI_NUMBYTES ( 2048 * 1024) // x KByte
    3. #pragma location=0xD0000000 //EXTRAM start
    4. static __no_init U32 HeapMem[1024 * 1024];
    6. #pragma location=0xD0200000 //EXTRAM GUI Conf
    7. static __no_init U32 extMem[GUI_NUMBYTES];
    9. U32* Get_ExtMemHeap (void)
    10. {
    11. return HeapMem;
    12. }
    14. void GUI_X_Config(void)
    15. {
    16. GUI_ALLOC_AssignMemory(extMem, GUI_NUMBYTES);
    17. }
    Display All