Driving the ili9488 LCD (4.0 inch cheap chinese clone)

robertoj · December 8, 2024

Hello, I have a new LCD which I believe is an ili4988 (although the vendor says ili9486 and st7796)

https://www.aliexpress.us/item/3256803856059047.html

I have read somewhere, that I can use an ili9341 spi driver, only by changing the resolution and changing the initialization script.

I looked in the waveshare website and github, they don't have anything for the ili9488

Then, I found some arduino code in http://www.lcdwiki.com/3.5inch_SPI_Module_ILI9488_SKU%3AMSP3520

(look for the "3.5 inch SPI Module Package(ILI9488)" link, then find the LCDWIKI_SPI.cpp

The initialization sequence is in line 1697:

Spoiler

				0xF7, 4, 0xA9, 0x51, 0x2C, 0x82,
				0xC0, 2, 0x11, 0x09,
				0xC1, 1, 0x41,
				0xC5, 3, 0x00, 0x0A, 0x80,
				0xB1, 2, 0xB0, 0x11,
				0xB4, 1, 0x02,
				0xB6, 2, 0x02, 0x22,
				0xB7, 1, 0xC6,
				0xBE, 2, 0x00, 0x04,
				0xE9, 1, 0x00,
				0x36, 1, 0x08,
				0xE0, 15, 0x00, 0x07, 0x10, 0x09, 0x17, 0x0B, 0x41, 0x89, 0x4B, 0x0A, 0x0C, 0x0E, 0x18, 0x1B, 0x0F,
				0xE1, 15, 0x00, 0x17, 0x1A, 0x04, 0x0E, 0x06, 0x2F, 0x45, 0x43, 0x02, 0x0A, 0x09, 0x32, 0x36, 0x0F,
				0x11, 0,
				TFTLCD_DELAY8, 120,
				0x29, 0

I am currently trying to convert it to a DTS-format init string, so that it fits my ili9341-fb.dts, which I made earlier this year:

Spoiler

/*
OrangePi Zero 3 -> ILI9341 LCD connections
SPI CLOCK = PH6
SPI DO (LCD MISO) = PH8 (OPIZ MISO)
SPI DI (LCD MOSI) = PH7 (OPIZ MOSI)
LCD DATA/CONTROL = PC7 *
LCD RESET = PC14 * could be any GPIO pin I want
CHIP SELECT = PH9
VCC = 3.3V PIN 17
GND = GND PIN 20
*/

/dts-v1/;
/plugin/;
/{
    compatible = "allwinner,sun50i-h616"; /*what is the H618*/
	fragment@0 {
	    target = <&pio>;
	    __overlay__{
	        display_pins: display_pins {
                    pins = "PC7", "PC14"; /* reset, DC pins, order does not matter*/
                    function = "gpio_out", "gpio_out";
                };
            };
	};
	fragment@1 {
        target = <&spi1>;
        __overlay__ {
            /* needed to avoid dtc warning */
            #address-cells = <1>;
            #size-cells = <0>;
            status="okay";
            pinctrl-names = "default";
            pinctrl-0 = <&spi1_pins>; /* Mux the PI to make sure they are set in spi Mode */
            cs-gpios = <&pio 7 9 0>;  /* PH9 chip select, H=7 */
            num-chipselects = <1>;
            display: display@0 {
                /*compatible = "adafruit,yx240qv29","ilitek,ili9341";*/
                compatible = "ilitek,ili9341";
                reg = <0>;
                pinctrl-names = "default";
                pinctrl-1 = <&display_pins>;
                spi-max-frequency = <40000000>;
                rotate = <270>; /* rotate for ili9341, rotation for yx240qv29 */
                bgr=<0>;
                fps = <15>;
                buswidth = <8>;
                height = <640>;
                width = <320>;
                reset-gpios = <&pio 2 14 1>; /* PC14 reset pin*/
                dc-gpios = <&pio 2 7 0>; /* PC7 Data control pin */
                debug = <3>;
                init = <0x10000b0 0x00
                        0x1000011
			0x20000ff
			0x100003a 0x55
			0x1000036 0x28
			0x10000c2 0x44
			0x10000c5 0x00 0x00 0x00 0x00
			0x10000e0 0x0f 0x1f 0x1c 0x0c 0x0f 0x08 0x48 0x98 0x37 0x0a 0x13 0x04 0x11 0x0d 0x00
			0x10000e1 0x0f 0x32 0x2e 0x0b 0x0d 0x05 0x47 0x75 0x37 0x06 0x10 0x03 0x24 0x20 0x00
			0x10000e2 0x0f 0x32 0x2e 0x0b 0x0d 0x05 0x47 0x75 0x37 0x06 0x10 0x03 0x24 0x20 0x00
			0x1000036 0x28
			0x1000011
			0x1000029>;
            };
        };
    };


    __overrides__ {
        rotate =  <&display>,"rotate:0";
        fps =     <&display>,"fps:0";
        debug =   <&display>,"debug:0";
    };
};

I am unsure how to start the init line, can someone help me?

Then, when I have that init string confirmed, I can use:

https://github.com/notro/panel-mipi-dbi/wiki

https://blog.csdn.net/CNflysky/article/details/125171176

To switch to the mipi-dbi driver, which would get me DRM (instead of FB)

robertoj · December 8, 2024

If you want to help, the datasheet PDF is in the lcdwiki download link in the previous post

I converted the arduino byte sequence into this:

Spoiler

init = <
0x10000F7 0xA9 0x51 0x2C 0x82 //adjust control 3
0x10000C0 0x11 0x09 //power control 1
0x10000C1 0x41 //power control 2
0x10000C5 0x00 0x0A 0x80 //voltage common control
0x10000B1 0xB0 0x11 //frame rate control
0x10000B4 0x02 //display inversion control
0x10000B6 0x02 0x22 //display function control
0x10000B7 0xC6 //entry mode set
0x10000BE 0x00 0x04 //HS lanes control
0x10000E9 0x00 //set image function
0x1000036 0x08 //memory access control
0x10000E0 0x00 0x07 0x10 0x09 0x17 0x0B 0x41 0x89 0x4B 0x0A 0x0C 0x0E 0x18 0x1B 0x0F //PGAMCTR positive gamma control
0x10000E1 0x00 0x17 0x1A 0x04 0x0E 0x06 0x2F 0x45 0x43 0x02 0x0A 0x09 0x32 0x36 0x0F //NGAMCTRL negative gamma control
0x1000011 //sleep out command
0x1000029>; //display on

The 4.0 inch ILI9488 starts up with RGB noise (non moving) in the left 3/4 of the screen, and a blurry, noisy image in the right 1/4 of the screen.

There's a TFTLCD_DELAY8, 120, which I don't know how to insert in the DTS,

and the original ili9341-fb.dts has a 0x20000ff, which I don't know whether I need it in the ili9488 init string

I inserted the:

0x10000b0 0x00 //interface mode control
0x1000011 //sleep out
0x20000ff //no idea

At the beginning, and there is no effect

I have no idea about the parameters buswidth, bgr, regwidth... what do they mean?

When I added regwidth=<16> (as shown in https://forum.armbian.com/topic/16536-35-screen-ili9486xpt2046-with-kernel-5914-sunxi/) I have a white-grayish screen

When I change it to regwidth=<24> I get the same RGB noise as without this parameter

When I swap the numbers in height and width like this:

height = <320>;
width = <640>;

I get the RGB noise in the left 3/4 of the screen, but the noisy desktop image (partial) in the top right corner of the LCD

I HAD A BIG TYPO: not 640, should be 480

height = <480>;
width = <320>;

Now, all the screen is mostly black, showing garbled text lines, then a garbled desktop on the top 2/3 of the screen

Changing the buswidth to 18 had no effect... I changed the regwidth=16 (made it worse) and txbuflen=32768 (no effect), as seen in https://4pda-to.translate.goog/forum/index.php?showtopic=1041048&st=40&_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=en&_x_tr_pto=wapp

Using the ili9486 driver as suggested here: https://github.com/notro/fbtft/issues/582 gave me a white screen

robertoj · December 8, 2024

Changin the parameter Interface Pixel Format (3Ah) to 0x55 (DPI=DBI=55=16 bits/pixel FIXED THE COLORS

Insert this after 0x20000ff (I still have no idea what it is for)

0x100003a 0x55 //pixel format. DBI=DPI=16bits per pixel (from ili9341 init)

Now, the problem is that the desktop image is reversed left to right...

I changed the memory access control to vertical refreshed order direction=1

0x1000036 0x28 //memory access control (was 0x08 in arduino code)

No effect, still reversed left to right (or up down if I rotated 180)

Is there any difference if this parameter is written twice in the original ili9341 init byte sequence?

Ok, it was register B6h Display function control. The bit SS shift direction control was set to 1 in the arduino INO, but it needs to be 0

Change 0x10000B6 0x02 0x22 //display function control

0x10000B6 0x02 0x02 //display function control (2nd param SS shift direction was 0x22 from arduino code)

Also, change the rotate DTS parameter from 270 to 90 and the spi speed to 60 MHz

Display works correctly in FBTFT mode... but not DRM yet, and not merged with the ADS7846 function (touch screen)

robertoj · December 9, 2024

Posting the FBTFT DTS only... while I am having trouble merging it with ads7846:

Spoiler

/*
OrangePi Zero 3 -> ILI9341 LCD connections
SPI CLOCK = PH6
SPI DO (LCD MISO) = PH8 (OPIZ MISO)
SPI DI (LCD MOSI) = PH7 (OPIZ MOSI)
LCD DATA/CONTROL = PC7 *
LCD RESET = PC14 * could be any GPIO pin I want
CHIP SELECT = PH9
VCC = 3.3V PIN 17
GND = GND PIN 20
*/

/dts-v1/;
/plugin/;
/{
    compatible = "allwinner,sun50i-h616"; /*what is the H618*/
	fragment@0 {
	    target = <&pio>;
	    __overlay__{
	        display_pins: display_pins {
                    pins = "PC7", "PC14"; /* reset, DC pins, order does not matter*/
                    function = "gpio_out", "gpio_out";
                };
            };
	};
	fragment@1 {
        target = <&spi1>;
        __overlay__ {
            /* needed to avoid dtc warning */
            #address-cells = <1>;
            #size-cells = <0>;
            status="okay";
            pinctrl-names = "default";
            pinctrl-0 = <&spi1_pins>; /* Mux the PI to make sure they are set in spi Mode */
            cs-gpios = <&pio 7 9 0>;  /* PH9 chip select, H=7 */
            num-chipselects = <1>;
            display: display@0 {
                /*compatible = "adafruit,yx240qv29","ilitek,ili9341";*/
                compatible = "ilitek,ili9341";
                //compatible = "ilitek,ili9486";
                reg = <0>;
                pinctrl-names = "default";
                pinctrl-1 = <&display_pins>;
                spi-max-frequency = <60000000>;
                //txbuflen = <32768>;
                rotate = <90>; /* rotate for ili9341, rotation for yx240qv29 */
                bgr=<1>;
                fps = <15>;
                buswidth = <8>;
                regwidth = <8>;
                height = <480>;
                width = <320>;
                reset-gpios = <&pio 2 14 1>; /* PC14 reset pin*/
                dc-gpios = <&pio 2 7 0>; /* PC7 Data control pin */
                debug = <3>;
init = <
0x10000b0 0x00 //interface mode control
0x1000011 //sleep out command
0x20000ff //no idea what this does
0x100003a 0x55 //pixel format. DBI=DPI=16bits per pixel (from ili9341 init)
0x10000F7 0xA9 0x51 0x2C 0x82 //adjust control 3
0x10000C0 0x11 0x09 //power control 1
0x10000C1 0x41 //power control 2
0x10000C5 0x00 0x0A 0x80 //voltage common control
0x10000B1 0xB0 0x11 //frame rate control
0x10000B4 0x02 //display inversion control
0x10000B6 0x02 0x02 //display function control (2nd param SS shift direction was 0x22 from arduino code)
0x10000B7 0xC6 //entry mode set
0x10000BE 0x00 0x04 //HS lanes control
0x10000E9 0x00 //set image function
0x1000036 0x08 //memory access control
0x10000E0 0x00 0x07 0x10 0x09 0x17 0x0B 0x41 0x89 0x4B 0x0A 0x0C 0x0E 0x18 0x1B 0x0F //PGAMCTR positive gamma control
0x10000E1 0x00 0x17 0x1A 0x04 0x0E 0x06 0x2F 0x45 0x43 0x02 0x0A 0x09 0x32 0x36 0x0F //NGAMCTRL negative gamma control
0x1000011 //sleep out command
0x1000029>; //display on
            };
        };
    };


    __overrides__ {
        rotate =  <&display>,"rotate:0";
        fps =     <&display>,"fps:0";
        debug =   <&display>,"debug:0";
    };
};

Ok, now I was able to merge the ads7946 function:

Spoiler

roberto@orangepizero3:~/ili9341$ cat ili9488-ads7846.dts
/dts-v1/;
/plugin/;
/ {
    compatible = "allwinner,sun50i-h616";

    fragment@0 {
        target = <&spi1>;
        __overlay__ {
            status = "okay";
	    cs-gpios = <&pio 7 9 0>,<&pio 2 15 0>; //PH9=CS0 for lcd, PC15=CS1 for touch.
            ili9488: ili9488@0 {
                compatible = "ilitek,ili9341";
                reg = <0>;
                pinctrl-names = "default";
                spi-max-frequency = <60000000>;
                rotate = <90>;
                bgr = <1>;
                fps = <15>;
                buswidth = <8>;
                regwidth = <8>;
                height = <480>;
                width = <320>;
                reset-gpios = <&pio 2 14 1>; // PC14
                dc-gpios = <&pio 2 7 0>; // PHC7
                debug = <3>;
                init = <
                    0x10000b0 0x00 //interface mode control
                    0x1000011 //sleep out command
                    0x20000ff //no idea what this does
                    0x100003a 0x55 //pixel format. DBI=DPI=16bits per pixel (from ili9341 init)
                    0x10000F7 0xA9 0x51 0x2C 0x82 //adjust control 3
                    0x10000C0 0x11 0x09 //power control 1
                    0x10000C1 0x41 //power control 2
                    0x10000C5 0x00 0x0A 0x80 //voltage common control
                    0x10000B1 0xB0 0x11 //frame rate control
                    0x10000B4 0x02 //display inversion control
                    0x10000B6 0x02 0x02 //display function control (2nd param SS shift direction was 0x22 from arduino code)
                    0x10000B7 0xC6 //entry mode set
                    0x10000BE 0x00 0x04 //HS lanes control
                    0x10000E9 0x00 //set image function
                    0x1000036 0x08 //memory access control
                    0x10000E0 0x00 0x07 0x10 0x09 0x17 0x0B 0x41 0x89 0x4B 0x0A 0x0C 0x0E 0x18 0x1B 0x0F //PGAMCTR positive gamma control
                    0x10000E1 0x00 0x17 0x1A 0x04 0x0E 0x06 0x2F 0x45 0x43 0x02 0x0A 0x09 0x32 0x36 0x0F //NGAMCTRL negative gamma control
                    0x1000011 //sleep out command
                    0x1000029>; //display on
            };

            ads7846: ads7846@1 {
                compatible = "ti,ads7846";
                reg = <1>;
                pinctrl-names = "default";
                spi-max-frequency = <1000000>;
                interrupt-parent = <&pio>;
                interrupts = <2 10 2>; // PC10 - IRQ
                pendown-gpio = <&pio 2 10 1>; // PC10
                
                // OPTIONS
                ti,x-min = /bits/ 16 <0>;
                ti,y-min = /bits/ 16 <0>;
                ti,x-max = /bits/ 16 <0xFFF>;
                ti,y-max = /bits/ 16 <0xFFF>;
                ti,pressure-min = /bits/ 16 <0>;
                ti,pressure-max = /bits/ 16 <0xFFF>;
                ti,x-plate-ohms = /bits/ 16 <400>;
                ti,swap-xy = <1>;
            };
        };
    };
};

WARNING: when the touchscreen is touched, a horizontal band (about 8mm) gets color-inverted around the cursor. Lowering the SPI speed does not help it

^ Does anybody have any idea why this is happening? It is bugging me horribly and the color-inversion is lasting until a whole screen refresh and it could stand garbled while doing nothing in lightdm+openbox... is this coming from the touch chip interrupts, or from the cursor animation? Would it go away with the panel-mipi-dbi-spi driver?

Next step is to use the panel-mipi-dpi-spi driver as shown here:

https://github.com/notro/panel-mipi-dbi/wiki ,

https://forums.raspberrypi.com/viewtopic.php?t=358240&hilit=Ili9341#p2165638and

https://blog.csdn.net/CNflysky/article/details/125171176

robertoj · December 10, 2024

My efforts to use the panel-mipi-dbi-spi driver:

DTS

Spoiler

roberto@orangepizero3:~/mipi-dbi$ cat mipi-ili9488-ads7846.dts
/dts-v1/;
/plugin/;
/ {
    compatible = "allwinner,sun50i-h616";
    fragment@0 {
        target = <&spi1>;
        __overlay__ {
            status = "okay";
	    cs-gpios = <&pio 7 9 0>,<&pio 2 15 0>; /*PH9=CS0 for lcd, PC15=CS1 for touch. Trying <0> instead of <&pio 7 9 0> */
            panel: panel@0 {
                compatible = "panel-mipi-dbi-spi";
                reg = <0>;
                spi-max-frequency = <40000000>;
                width-mm=<84>;
                height-mm=<56>;
                reset-gpios = <&pio 2 14 0>; // PC14
                dc-gpios = <&pio 2 7 0>; // PHC7
                write-only;
                debug = <3>;
                panel-timing {
                    hactive = <480>;
                    vactive = <320>;
                    hback-porch = <0>;
                    vback-porch = <0>;
                    clock-frequency = <0>;
                    hfront-porch = <0>;
                    hsync-len = <0>;
                    vfront-porch = <0>;
                    vsync-len = <0>;
                };
            };

            ads7846: ads7846@1 {
                compatible = "ti,ads7846";
                reg = <1>;
                pinctrl-names = "default";
                spi-max-frequency = <1000000>;
                interrupt-parent = <&pio>;
                interrupts = <2 10 2>; /* PC10 - IRQ */
                pendown-gpio = <&pio 2 10 1>; /* PC10 */
                
                /* OPTIONS */
                ti,x-min = /bits/ 16 <0>;
                ti,y-min = /bits/ 16 <0>;
		ti,x-max = /bits/ 16 <0xFFF>;
		ti,y-max = /bits/ 16 <0xFFF>;
                ti,pressure-min = /bits/ 16 <0>;
                ti,pressure-max = /bits/ 16 <0xFFF>;
                ti,x-plate-ohms = /bits/ 16 <400>;
                ti,swap-xy = <1>;
	    };
        };
    };
};

Init sequence panel-mipi-dbi-spi.txt

Spoiler

command 0xB0 0x00 #interface mode control
command 0x11 #sleep out command
command 0x3A 0x55 #interface pixel format. DBI=DPI=16bits per pixel (from ili9341 init)
command 0xF7 0xA9 0x51 0x2C 0x82 #adjust control 3
command 0xC0 0x11 0x09 #power control 1
command 0xC1 0x41 #power control 2
command 0xC5 0x00 0x0A 0x80 #voltage common control
command 0xB1 0xB0 0x11 #frame rate control
command 0xB4 0x02 #display inversion control
command 0xB6 0x02 0x02 #display function control
command 0xB7 0xC6 #entry mode set
command 0xBE 0x00 0x04 #HS lanes control
command 0xE9 0x00 #set image function
command 0x36 0x28 #memory access control
command 0xE0 0x00 0x07 0x10 0x09 0x17 0x0B 0x41 0x89 0x4B 0x0A 0x0C 0x0E 0x18 0x1B 0x0F #PGAMCTR
command 0xE1 0x00 0x17 0x1A 0x04 0x0E 0x06 0x2F 0x45 0x43 0x02 0x0A 0x09 0x32 0x36 0x0F #NGAMCTRL
command 0x11 #sleep out command
delay 120
command 0x29 #display on

compile and install this init command byte sequence (I don't know how to use an arbitrary bin file in the DTS😞

./mipi-dbi-cmd panel-mipi-dbi.bin panel-mipi-dbi-spi.txt
sudo cp panel-mipi-dbi.bin /lib/firmware/

Make sure that the DTS was given to the kernel: look for "Applying user provided DT overlay mipi-ili9488-ads7846.dtbo" without errors before starting kernel

Make sure that the panel-mipi-dbi.bin was read by the driver: dmesg|grep mipi , look for no errors like "No config file found for compatible 'ili9488-init,panel-mipi-dbi-spi' (error=-2)"

Successfully loaded driver should look lije this:

roberto@orangepizero3:~$ dmesg|grep mipi
[    5.690191] panel-mipi-dbi-spi spi1.0: supply power not found, using dummy regulator
[    5.690338] panel-mipi-dbi-spi spi1.0: supply io not found, using dummy regulator
[    5.713936] [drm] Initialized panel-mipi-dbi 1.0.0 20220103 for spi1.0 on minor 2
[    6.205598] panel-mipi-dbi-spi spi1.0: [drm] fb0: panel-mipi-dbid frame buffer device

The panel-mipi-dbi-spi driver in Linux 6.7.12.has the parameters described in:

https://elixir.bootlin.com/linux/v6.7.12/source/Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml

Upgrading to Linux 6.11+ has more parameters, like BGR666 color format

https://elixir.bootlin.com/linux/v6.12.4/source/Documentation/devicetree/bindings/display/panel/panel-mipi-dbi-spi.yaml

The panel-mipi-dbi-spi wiki: https://github.com/notro/panel-mipi-dbi/wiki

This is what I get so far

I think I need to upgrade to Linux 6.12 and experiment with other "Memory Access Control 0x36" bit values in panel-mipi-dbi-spi.txt

robertoj · December 13, 2024

THANKS TO USER KungFuPancake, who showed me his github repo, where he indicates to use the latest Armbian-edge, and provides the a command byte sequence for the ili9488

https://github.com/KungfuPancake/v0_ips_touch_display?tab=readme-ov-file

If you see inverted colors, edit the panel-mipi-dbi-spi.txt and comment the line #command 0x21 before using the mipi-dbi-cmd

If you have the cheap chinese clone LCD (see first post), use this DTS (change the gpio codes as needed):

Spoiler

roberto@orangepizero3:~/mipi-ili9488/v0_ips_touch_display$ cat orangepi-zero3-ads7846.dts
/dts-v1/;
/plugin/;
/ {
    compatible = "allwinner,sun50i-h616";
    fragment@0 {
        target = <&spi1>;
        __overlay__ {
            status = "okay";
	    cs-gpios = <&pio 7 9 0>,<&pio 2 15 0>; // PH9=CS0 for lcd, PC15=CS1 for touch
            panel: panel@0 {
                compatible = "panel-mipi-dbi-spi";
                reg = <0>;
                spi-max-frequency = <40000000>;
                width-mm=<84>;
                height-mm=<56>;
                reset-gpios = <&pio 2 14 0>; // PC14
                dc-gpios = <&pio 2 7 0>; // PHC7
                write-only;
                format = "b6x2g6x2r6x2";
                panel-timing {
                    hactive = <480>;
                    vactive = <320>;
                    hback-porch = <0>;
                    vback-porch = <0>;
                    clock-frequency = <0>;
                    hfront-porch = <0>;
                    hsync-len = <0>;
                    vfront-porch = <0>;
                    vsync-len = <0>;
                };
            };

            ads7846: ads7846@1 {
                compatible = "ti,ads7846";
                reg = <1>;
                pinctrl-names = "default";
                spi-max-frequency = <1000000>;
                interrupt-parent = <&pio>;
                interrupts = <2 10 2>; /* PC10 - IRQ */
                pendown-gpio = <&pio 2 10 1>; /* PC10 */
                
                /* OPTIONS */
                ti,x-min = /bits/ 16 <0>;
                ti,y-min = /bits/ 16 <0>;
		ti,x-max = /bits/ 16 <0xFFF>;
		ti,y-max = /bits/ 16 <0xFFF>;
                ti,pressure-min = /bits/ 16 <0>;
                ti,pressure-max = /bits/ 16 <0xFFF>;
                ti,x-plate-ohms = /bits/ 16 <400>;
                ti,swap-xy = <1>;
	    };
        };
    };
};

robertoj · December 14, 2024

Is anyone getting a jumpy cursor, and garbled image around the areas of window refresh? (only at times of touching the screen)

I suspect it is caused by sharing the SPI bus with the ads7846 (XPT2040)... anyone knows?

I don't have this issue when I use the USB mouse.

I also experience the LCD going 3/4 black and frozen, when there are no input events. It restores to normal when I touch the screen or move the mouse (with a white washout/flash in the LCD).

My app is continuosly painting pixels, and it happens after a few minutes of no input events.

I already have:

xset s off &
xset s noblank
xset s -dpms

But it seems that I don't have "xset" installed in my debian bookworm. Fixed with apt install x11-xserver-utils

robertoj · March 5

I found that you can rotate the ili9488 display 180 degrees, by changing the LCD initialization command in panel-mipi-dbi-spi.txt:

Change: command 0x36 0xE0

To: command 0x36 0x20

(changes memory access control row and column order from:

starting from the corner near the VCC pin, to

starting from the corner opposite from the VCC pin)

Then, open /usr/share/X11/xorg.conf.d/99-calibration, and add:

Option "InvertX" "1"

Option "InvertY" "1"

Reference:

https://focuslcds.com/wp-content/uploads/Drivers/ILI9488.pdf

https://forums.raspberrypi.com/viewtopic.php?t=173993

I hope it helps someone, or to myself in the future

le51 · March 5

Hi @robertoj, it's really interesting.. For now I just can get my ili9488 display working exclusively on a RBPi using JUJ's fbcp https://github.com/juj/fbcp-ili9341

Tell me if I resume well:

You got the display to work with the old fbtft driver, but touch seems unsure

You're using the tinydrm and it's fully functionnal

What is your kernel version ?

robertoj · March 5

I have the ili9488 working in orange pi zero 3 with my DTS in https://forum.armbian.com/topic/47971-driving-the-ili9488-lcd-40-inch-cheap-chinese-clone/#findComment-208446

and the panel-mipi-dbi-spi.txt from https://github.com/KungfuPancake/v0_ips_touch_display?tab=readme-ov-file

My DTS file uses the new panel-mipi-dbi-spi driver, which is not fbtft, it is tinydrm.

Kernel 6.12, built from https://github.com/NickAlilovic/build

I can use X11 completely fine, but I havent tried wayland and h264 acceleration yet. Can you try it?

The only problems I see:

Cursor has some "jumpiness" when pressing the touch panel (ads7846).

Graphic pixel noise appears when I am dragging an X11 window with finger. But it returns to normal after the dragging event. (doesn't happen when I drag with USB mouse).

I think the noise won't happen if I can make a separate soft-SPI for the touch function.

Has anybody tried xrandr? I learned to use it in my laptop, but I don't have my orange pi zero 3 available. Can anyone try:

$ xrandr --output SPI-1 --rotate left

Then replace left with: inverted, right and normal

This should take care of the touch at the same time, but someone needs to try it.

Edited Saturday at 12:17 AM by robertoj

le51 · Saturday at 11:21 PM

Hi, sorry for the delay.

On 3/5/2025 at 7:22 PM, robertoj said:

My DTS file uses the new panel-mipi-dbi-spi driver, which is not fbtft, it is tinydrm.

I can't believe it !

This is just great.

I will give it a try the next few days. Many thanks

robertoj · Monday at 03:50 AM

I had time to test xrandr with my ili9488 and mipi-dbi-spi

while the LCD is showing X11+lightdm+openbox, I logged in via SSH and typed:

roberto@orangepizero3:~$ DISPLAY=:0.0 xrandr -q
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 480 x 320, current 480 x 320, maximum 480 x 320
default connected 480x320+0+0 0mm x 0mm
   480x320        0.00*

roberto@orangepizero3:~$ DISPLAY=:0.0 xrandr --output default --rotate left
xrandr: output default cannot use rotation "left" reflection "none"

So, I can't rotate the LCD display with xrandr, and the only option is the 2 actions I shared on March 4

Note: the 4 rotate options are normal, right, left and inverted. None of them worked

le51 · Monday at 11:56 AM

So I've looked into my drawers and, unfortunately, I can't get my hands on the ili9488 display I own. I will order a new one.

But I've got another display of the same type (with the red PCB and 14 pins and resistive touch) with ili9486 driver IC.

In LCDWIKI_SPI.cpp, there's an init sequence for that chip, but I'm really confused.

On 12/13/2024 at 6:11 AM, robertoj said:

THANKS TO USER KungFuPancake, who showed me his github repo, where he indicates to use the latest Armbian-edge, and provides the a command byte sequence for the ili9488

Means that you have use this file: https://github.com/KungfuPancake/v0_ips_touch_display/blob/main/panel-mipi-dbi-spi.txt ?

It's really different from what is in LCDWIKI_SPI.cpp around line 1697 (for ili9488)

Edited Monday at 11:58 AM by le51

robertoj · Monday at 08:46 PM

Yes, you must use that panel-mipi-dbi-spi.txt, process it with the python script, copy it to the right folder, and use the DTS I shared last.

I havent seen another command byte sequence for ili9488. Can you post the link to the download (to make sure I will see the same thing).

Can you make a hypothetical byte sequence from the LCDWIKI_SPI.cpp?

le51 · Tuesday at 10:22 AM

This is from panel-mipi-dbi-spi.txt

command 0xE0 0x00 0x03 0x09 0x08 0x16 0x0A 0x3F 0x78 0x4C 0x09 0x0A 0x08 0x16 0x1A 0x0F
command 0xE1 0x00 0x16 0x19 0x03 0x0F 0x05 0x32 0x45 0x46 0x04 0x0E 0x0D 0x35 0x37 0x0F

This is from LCDWIKI_SPI.cpp for ili9488:

0xE0, 15, 0x00, 0x07, 0x10, 0x09, 0x17, 0x0B, 0x41, 0x89, 0x4B, 0x0A, 0x0C, 0x0E, 0x18, 0x1B, 0x0F,

0xE1, 15, 0x00, 0x17, 0x1A, 0x04, 0x0E, 0x06, 0x2F, 0x45, 0x43, 0x02, 0x0A, 0x09, 0x32, 0x36, 0x0F,