NRF9161DK LVGL DISPLAY

[DanielDelgado]

Hi, 

I am trying to use an ST7789 display with the NRF9161DK, I was following this guide but got no luck:

https://devzone.nordicsemi.com/guides/nrf-connect-sdk-guides/b/peripherals/posts/lvgl-on-a-tft-lcd-display-with-the-nrf9160-dk.

I'm lost on the approach, I switched to a zephyr sample LVGL and configured it for the NRF9161DK and the ST7789, but have some errors configuring the diplay;

ncs\v2.6.1\zephyr\samples\subsys\display\lvgl and ncs\v2.6.1\zephyr\samples\modules\lvgl\demos. 

Wich one should I use?

And the most important question, am I on the rigth path? Can I configure one of the LVGL Zephyr samples to work with the ST7789 and the nrf9161DK?

Can you give me some guidance please?

Thank You

[runsiv]

Hi Daniel

The devzone blog is some years old and there has been a lot of changes to Zephyr and our SKD since the time it was written so I would presume some steps are no longer possible to follow. 

I think I would start with the ncs\v2.6.1\zephyr\samples\modules\lvgl\demos as it is a simple "hello world" sample. Could you post the error you got when you tried to use the sample?

I think you will need to build your application with the dshield flag like seen here: https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/boards/shields/st7789v_generic/doc/index.html 

What is your VDD_GPIO  configured to? The display need 3V3

Regards

Runar

[DanielDelgado]

Hi runsiv,

Thank you so much for your help, I followed your instructions and it built and flashed perfectly, now I have another problem, the screen doesn't show anything, I tested two screen and nothing (and both examples). 

Everything looks fine, i tested the pins and they deliver 3.3v except for p0.11 p0.12 and p0.13, I dont have an oscilloscope in hand, so can't test the spi, the only thing that can be wrong is on P0.13 and P.0.11.

I don't know where the spi is initialized, but my overlay looks like this:

and this is the st7789 240x240 overlay I have:

/*

 * Copyright (c) 2019 Jan Van Winkel <[email protected]>

 * Copyright (c) 2019 PHYTEC Messtechnik GmbH

 *

 * SPDX-License-Identifier: Apache-2.0

 */

/ {

    chosen {

        zephyr,display = &st7789v_st7789v_waveshare_240x240;

    };

};

&arduino_spi {

    status = "okay";

    cs-gpios = <&arduino_header 16 GPIO_ACTIVE_LOW>;    /* D10 */

    st7789v_st7789v_waveshare_240x240: st7789v@0 {

        compatible = "sitronix,st7789v";

        spi-max-frequency = <20000000>;

        reg = <0>;

        cmd-data-gpios = <&arduino_header 15 GPIO_ACTIVE_LOW>;  /* D9 */

        reset-gpios = <&arduino_header 14 GPIO_ACTIVE_LOW>; /* D8 */

        width = <240>;

        height = <240>;

        x-offset = <0>;

        y-offset = <0>;

        vcom = <0x19>;

        gctrl = <0x35>;

        vrhs = <0x12>;

        vdvs = <0x20>;

        mdac = <0x00>;

        gamma = <0x01>;

        colmod = <0x05>;

        lcm = <0x2c>;

        porch-param = [0c 0c 00 33 33];

        cmd2en-param = [5a 69 02 01];

        pwctrl1-param = [a4 a1];

        pvgam-param = [D0 04 0D 11 13 2B 3F 54 4C 18 0D 0B 1F 23];

        nvgam-param = [D0 04 0C 11 13 2C 3F 44 51 2F 1F 1F 20 23];

        ram-param = [00 F0];

        rgb-param = [CD 08 14];

    };

};

the board is set at 3.3v and the backlight of the lcd is on.

One of the LCDs has pins: GND,VCC,SCL,SDA,RES,DC,BLK (waveshare 240x240)

The other: GND VCC SCL SDA RES DC CS BLK (240X280)

Thank you,

Daniel

[runsiv]

Hi Daniel

Can you also show me your pin control related to &arduino_spi? 

I would expect your overlay to look something like this(for as an example)

arduino_spi: &spi3 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	cs-gpios = <&arduino_header 16 GPIO_ACTIVE_LOW>, /* D10 */
		   <&gpio0 20 GPIO_ACTIVE_LOW>;
	pinctrl-0 = <&spi3_default>;
	pinctrl-1 = <&spi3_sleep>;
	pinctrl-names = "default", "sleep";

	gd25wb256: gd25wb256e3ir@1 {
		compatible = "jedec,spi-nor";
		status = "disabled";
		reg = <1>;
		spi-max-frequency = <8000000>;
		size = <268435456>;
		has-dpd;
		t-enter-dpd = <3000>;
		t-exit-dpd = <40000>;
		sfdp-bfp = [
			e5 20 f3 ff  ff ff ff 0f  44 eb 08 6b  08 3b 42 bb
			ee ff ff ff  ff ff 00 ff  ff ff 00 ff  0c 20 0f 52
			10 d8 00 ff  44 7a c9 fe  83 67 26 62  ec 82 18 44
			7a 75 7a 75  04 c4 d5 5c  00 06 74 00  08 50 00 01
			];
		jedec-id = [c8 65 19];
	};
};

I would also expect  a status="okay" inside the st7789v_st7789v_waveshare_240x240. I would also verify that you have enabled the peripheral in your prj.conf

Regards

Runar

[DanielDelgado]

This is how my pin control definition looks like (the same apparently):

arduino_spi: &spi3 {
    compatible = "nordic,nrf-spim";
    status = "okay";
    cs-gpios = <&arduino_header 16 GPIO_ACTIVE_LOW>, /* D10 */
            <&gpio0 20 GPIO_ACTIVE_LOW>;
    pinctrl-0 = <&spi3_default>;
    pinctrl-1 = <&spi3_sleep>;
    pinctrl-names = "default", "sleep";

    gd25wb256: gd25wb256e3ir@1 {
        compatible = "jedec,spi-nor";
        status = "disabled";
        reg = <1>;
        spi-max-frequency = <8000000>;
        size = <268435456>;
        has-dpd;
        t-enter-dpd = <3000>;
        t-exit-dpd = <40000>;
        sfdp-bfp = [
            e5 20 f3 ff  ff ff ff 0f  44 eb 08 6b  08 3b 42 bb
            ee ff ff ff  ff ff 00 ff  ff ff 00 ff  0c 20 0f 52
            10 d8 00 ff  44 7a c9 fe  83 67 26 62  ec 82 18 44
            7a 75 7a 75  04 c4 d5 5c  00 06 74 00  08 50 00 01
            ];
        jedec-id = [c8 65 19];
    };
};

I also enabled spi in main: #include <zephyr/drivers/spi.h>

 

, and this is my prj.conf:

CONFIG_MAIN_STACK_SIZE=4096
CONFIG_LOG=y
CONFIG_SHELL=y

CONFIG_LVGL=y
CONFIG_LV_Z_MEM_POOL_SIZE=49152
CONFIG_LV_Z_SHELL=y
CONFIG_LV_USE_MONKEY=y

CONFIG_DISPLAY=y
CONFIG_INPUT=y

CONFIG_LV_FONT_MONTSERRAT_12=y
CONFIG_LV_FONT_MONTSERRAT_14=y
CONFIG_LV_FONT_MONTSERRAT_16=y

# Benchmark Demo
CONFIG_LV_USE_FONT_COMPRESSED=y

CONFIG_SPI=y

Still no errors, and nothing on screen.

Thank you,

Daniel

[runsiv]

Ah, you are missing 

CONFIG_ST7789V=y

Which is needed to enable the driver for the display. 

Regards

Runar