ST7789v3 screen working

Duo
1

Hi!

I got an ST7789v3 working with the Milk-v Duo :smiley:

IMG_20230821_002157
IMG_20230821_0021571920×1440 167 KB

It’s really easy to make it work, here are the instructions on how to do it with the latest SDK.

  1. Enable the SPI device in the mux config.

Modify the file build/boards/cv180x/cv1800b_milkv_duo_sd/u-boot/cvi_board_init.c and change with this:

        //Default config of sd1 removed as SPI2 will use its pins
        // sd1
        //PINMUX_CONFIG(SD1_D3, PWR_GPIO_18);
        //PINMUX_CONFIG(SD1_D2, PWR_GPIO_19);
        //PINMUX_CONFIG(SD1_D1, PWR_GPIO_20);
        //PINMUX_CONFIG(SD1_D0, PWR_GPIO_21);
        //PINMUX_CONFIG(SD1_CMD, PWR_GPIO_22);
        //PINMUX_CONFIG(SD1_CLK, PWR_GPIO_23);

        //Enable SPI2
        pinmux_config(PINMUX_SPI2);
  1. Create the ST screen connected to the SPI port in the device tree.

Modify the file build/boards/cv180x/cv1800b_milkv_duo_sd/dts_riscv/cv1800b_milkv_duo_sd.dts and add this:

&spi2 {
        status = "okay";
        cs-gpios = <&porta 18 0>;

        spidev@0 {
                status = "disabled";
        };

        st7789v: st7789v@0{
                compatible = "sitronix,st7789v";
                reg = <0>;
                status = "okay";
                spi-max-frequency = <48000000>;
                spi-cpol;
                spi-cpha;
                rotate = <90>; //This depends on your screen
                fps = <60>;
                rgb;
                buswidth = <8>;
                dc-gpios = <&porta 24 GPIO_ACTIVE_HIGH>;
                reset-gpios = <&porta 23 GPIO_ACTIVE_HIGH>;
                debug = <0x4000000>;
        };

};
  1. Enable the device drivers.

Modify the file build/boards/cv180x/cv1800b_milkv_duo_sd/linux/cvitek_cv1800b_milkv_duo_sd_defconfig and add this.

CONFIG_SPI_MASTER=y
CONFIG_SPI_DESIGNWARE=y
CONFIG_SPI_DW_MMIO=y
CONFIG_SPI_SPIDEV=y

CONFIG_FB=y
CONFIG_FB_TFT=y
CONFIG_FB_TFT_ST7789V=y

That’s it! With this you should have the fb0 device and you can write to it.

The device is connected like this:

Duo       |       st7789
GND       |         GND
3.3v(out) |         VCC
GPIO23    |         SCL
GPIO22    |         SDA
GPIOA23   |         RES
GPIOA24   |         DC
GPIO18    |         CS

Thanks to @firstman as his post has been really helpful to get it working!

Cheers!

3 Likes
2

I haven’t tried yet, but just in case you have, have you gotten x or wayland to work on it? Also does it do fine to detect the resolution of your display?

3

Hi.

No, I haven’t tried X nor Wayland, this screen is too small for it (only 172 pixels tall), I will wait until I receive a 240x320 one.

About resolution, it’s fixed at 240x320 as the controller is what supports as far as I know, if the screen is smaller you can adjust the vertical scroll start address in the initialization at linux_5.10/drivers/staging/fbtft/fb_st7789v.c

Cheers!

1 Like