SSD1351 SPI Driver for Zephyr RTOS

This is a Zephyr RTOS driver for the Solomon SSD1351 OLED display (using SPI). It supports multiple pixel formats, custom grayscale for better display quality, and flicker-free operation.

Features

• SPI interface support for communication with the SSD1351 display.
• Supports PIXEL_FORMAT_RGB565, PIXEL_FORMAT_BGR565, and PIXEL_FORMAT_RGB888 (RGB888 is converted to RGB666 due to the SSD1351's limitations).
• Custom grayscale table applied for improved display quality.
• Flicker-free operation (including capturing the display with a phone camera, due to customized IC clock settings).
• Compatible with the LVGL graphics library.
• Rotation support.
• Compatible with Waveshare 1.5-inch RGB OLED Display Module.

Adding Driver To Zephyr Project

CMakeLists.txt

To include the driver in your Zephyr project, specify its path in the CMakeLists.txt file as follows:

set(ZEPHYR_EXTRA_MODULES
    ${CMAKE_CURRENT_SOURCE_DIR}/drivers/ssd1351-zephyr-driver  # Change it to your path
)

Configuration in prj.conf

Add the following configuration options to your prj.conf to enable SPI and the SSD1351 driver:

CONFIG_SPI=y
CONFIG_DISPLAY=y
CONFIG_SSD1351=y

Example SPI Configuration in Device Tree

Ensure that the SPI interface is properly configured in the Device Tree. Below is an example configuration for the SPI3 interface:

#include <zephyr/dt-bindings/display/panel.h>

&spi3 {
    compatible = "nordic,nrf-spim";
    status = "okay";
    pinctrl-0 = <&spi3_default>;
    pinctrl-1 = <&spi3_sleep>;
    pinctrl-names = "default", "sleep";
    cs-gpios = <&gpio0 20 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;

    ssd1351: ssd1351@0 {
        status = "okay";
        compatible = "solomon,ssd1351";
        spi-max-frequency = <24000000>;
        reg = <0>;
        reset-gpios = <&gpio0 6 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>;
        dc-gpios = <&gpio0 24 GPIO_ACTIVE_HIGH>;
        width = <128>;
        height = <128>;
        rotation = <0>;
        pixel-format = <PANEL_PIXEL_FORMAT_RGB_888>;
    };
};

The following pixel formats are supported:

PANEL_PIXEL_FORMAT_RGB565
PANEL_PIXEL_FORMAT_BGR565
PANEL_PIXEL_FORMAT_RGB888

Note: RGB888 is converted to RGB666 due to the SSD1351's hardware limitations, as it doesn't support full 888 color depth.

Tested Hardware

This driver has been developed and tested on the Waveshare 1.5-inch RGB OLED Display Module. You can find more information and purchase the module here.

Contributing

Pull requests and issues are always welcome! Feel free to contribute to make this project better.