LVGL Screen Rotation Issue

How-to
1

Hi,

I designed my LVGL UI in 480x800, but my display is 800x480 (landscape). I need to rotate the screen 90 degrees.

I tried:
disp_drv.sw_rotate = 1;
lv_disp_set_rotation(disp, LV_DISP_ROT_90);
but it didn’t work.

**Is there an alternative way to rotate the screen in LVGL?

Thanks!

1 Like
2

what does it mean? you see ui in landscape orientation ? how did you configured display - 800x480 ?

3

Hi,
This is my zephyr ltdc configuration, i attached expected and actual image below ,

&ltdc {
    pinctrl-0 = <&ltdc_vsync_pi9 &ltdc_hsync_pi10 &ltdc_g6_pi11 &ltdc_de_pf10
                 &ltdc_b5_pa3 &ltdc_g2_pa6 &ltdc_r3_pb0 &ltdc_r6_pb1
                 &ltdc_g5_pb11 &ltdc_r4_ph10 &ltdc_r5_ph11 &ltdc_r7_pg6
                 &ltdc_clk_pg7 &ltdc_b2_pc9 &ltdc_b3_pa8 &ltdc_b4_pa10
                 &ltdc_g3_ph14 &ltdc_g4_ph15 &ltdc_g7_pi2 &ltdc_b6_pb8
                 &ltdc_b7_pb9>;
// pinctrl-0 = <&pinctrl_ltdc>;
    pinctrl-names = "default";
ext-sdram = <&sdram1>;
    status = "okay";

    width = <800>;  // Horizontal resolution
    height = <480>; // Vertical resolution
   
    pixel-format = <PANEL_PIXEL_FORMAT_RGB_565>; // 32-bit color format
   
    display-timings {
        compatible = "zephyr,panel-timing";
        de-active = <0>;         // Data Enable polarity
        pixelclk-active = <0>;   // Pixel Clock polarity
        hsync-active = <0>;      // Horizontal Sync polarity
        vsync-active = <0>;      // Vertical Sync polarity
        hsync-len = <19>;        // Horizontal Sync pulse width
        vsync-len = <9>;         // Vertical Sync pulse width
        hback-porch = <46>;      // Horizontal Back Porch
        vback-porch = <23>;      // Vertical Back Porch
        hfront-porch = <210>;    // Horizontal Front Porch
        vfront-porch = <22>;     // Vertical Front Porch
       
    };

    def-back-color-red = <0>;
    def-back-color-green = <0xff>; // Green background
    def-back-color-blue = <0>;
};

expected
expected479×812 9.5 KB

Actual
Actual1600×1600 480 KB

4

What version of Zephyr are you using? As far as I remember in versions below 2.7 LVGL resolution defined independent of display resolution.

5

using zephyr version 4.

6

are you sure it is called in your appl (in particular after lvgl has been initilized, lvgl_init() call) ?

EDIT: and what is disp ?

7

Yes, I am calling lv_disp_set_rotation after calling lv_init. And I don’t understand your question about “disp”.

8

you are using disp variable. what is it ? how is it initilized ?

I think lv_disp_set_rotation() should be called after lv_disp_drv_register() in lvgl_init(), and if you are want to use single display lv_disp_get_default() instead of disp.
I use lv_disp_set_rotation(lv_disp_get_default(), disp_rot); in user application code (not in zephyr code)
lvgl_init() is a part of zephyr module code, and with

SYS_INIT(lvgl_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);

executed just before application code (main).

9

Thanks for you suggestion, i have one more doubt about screen rotation

my display natually build-in horizontal co-ordination of the framebuffer , but my screen design was vertical co-ordination how to change co-ordination horizontal to verical using frame buffer,
note : I don’t have any specific display driver for rotation.