LVGL ported to the 7-inch Riverdi STM32 Embedded Displays (STM32H757XIH86)

Overview

STM32 Embedded 7.0” display is all-in-one complete and open-platform solution being able to independently handle the visual layer of devices with the need for high computing performance. The STM32 Embedded Displays series are industrial-quality LCD-TFT solutions based on the STM32H757XIH6 microcontroller. It has been designed in a way that allows to meet most of the hardware and programming challenges faced by engineers, including access to all interfaces.

Buy

You can purchase the 7-inch Riverdi STM32 Embedded Displays from several sources:

• Riverdi's website
• Mouser
• TME

Benchmark

Buffer configuration

For the best performance the example is configured for 16-bit RGB565 color format, although the native color format of the panel is RGB888. The project uses LVGL's LV_DISPLAY_RENDER_MODE_PARTIAL mode with two 60 line (1/10th of the height of the screen) buffers. A single buffer requires 120kB memory.

If more memory is needed for the application, a single buffer may be used, or the size of the buffer can be reduced. There is no strict rule for the optimum buffer size, as it depends on many factors (screen size, screen content, processor speed, RAM speed, type of the LCD interface). In practice a 1/10th screen size buffer is a good compromise between performance and memory use, but this is an area for potential optimization, depending on the application.

The board can also handle 32-bit ARGB8888 format rendering, but the performance will be lower.

Direct mode rendering seems to be not feasible on this board, because in direct mode the color format must be the native format -- i.e., ARGB8888 --, and apparently the SDRAM memory is not fast enough for two full sized 32-bit buffers.

The buffer configuration can be found in the file lv_port_riverdi_70-stm32h7/CM7/Core/Src/lvgl_port_display.c.

Specification

CPU and memory

• MCU STM32H757XIH6 (Cortex-M7 + M4 core, 480MHz)
• RAM 1MB internal, 8MB external (32 bit access)
• Flash 2MB internal, 64MB external flash
• GPU Chrom-ART (DMA2D)

Display

• Resolution 1024x600
• Display size 7"
• Interface MIPI
• Color depth 24bit
• Technology IPS
• DPI 170 px/inch
• Touch pad Industrial Capacitive or no touch

Others

• RS485, RS232
• Expansion connector (40 GPIOs to access 2x I2C, 1x UART, 1x USART, 1x SPI, 1x USB, 7x PWMs, 2x DACs, 2x ADCs)
• 2x CAN FD
• RiBUS connector
• USB
• Haptic feedback driver output (DRV2605L)

Getting started

To be able to flash and debug your program you will need to purchase an SWD debug probe which supports the ARM Cortex-M7 core, e.g the STMicro ST-Link V2/V3 or the Segger J-Link.

Hardware setup

• Connect a 6-48V power supply to the POWER header on the board using the supplied cable. The board draws about 0.55A at 9V.
• Connect a debug probe to the SWD header using the supplied cable.

Software setup

• Install STM32 CubeIDE with processor support for the STM32H757XIH6.

Run the project

• Clone the project: git clone --recursive https://github.com/lvgl/lv_port_riverdi_70-stm32h7
• Open STM32CubeIDE and import project: File => Open Projects from File System... => Directory => Select the "riverdi-70-stm32h7-lvgl/STM32CubeIde" folder => Finish
• In the Project Explorer open the riverdi-70-stm32h7-lvgl folder, and select riverdi-70-stm32h7-lvgl_CM7 subproject.
• Build the project (for the best performance use Release configuration with -O2 flag): Project => Build Project
• Click the Run button to flash the project

Debugging

• After building the project click the Debug button to flash the project. You will need to select the correct debug probe for the first run.

Notes

This repository supports all configuration of 7-inch Riverdi STM32 Embedded Displays:

• RVT70HSSNWC00-B - STM32H757XIH86, Capacitive Touch Panel, Optical bonding, uxTouch
• RVT70HSSNWC00 - STM32H757XIH86, Capacitive Touch Panel, Air bonding, uxTouch
• RVT70HSSFWCA0 - STM32H757XIH86, Capacitive Touch Panel, Air bonding, aTouch
• RVT70HSSNWCA0 - STM32H757XIH86, Capacitive Touch Panel, Air bonding, aTouch
• RVT70HSSFWN00 - STM32H757XIH86
• RVT70HSSNWN00 - STM32H757XIH86

Contribution and Support

If you find any issues with the development board feel free to open an Issue in this repository. For LVGL related issues (features, bugs, etc) please use the main lvgl repository.

If you found a bug and found a solution too please send a Pull request. If you are new to Pull requests refer to Our Guide to learn the basics.