NeoChrom¶
LVGL integrates NeoChrom as a draw unit.
Ready-to-use Projects that have NeoChrom enabled¶
lv_port_riverdi_stm32u5 is a ready-to-use port for the Riverdi STM32 5.0" Embedded Display (STM32U599NJH6Q or STM32U5A9NJH6Q) which has NeoChrom enabled. Follow the instructions in the readme to get started.
lv_port_stm32u5g9j-dk2 is a ready-to-use port for the STM32U5G9J-DK2 devkit with a 5.0" display and a NeoChrom VG GPU. Follow the instructions in the readme to get started.
Usage and Configuration¶
Enable the renderer by setting LV_USE_NEMA_GFX to 1 in
lv_conf.h. If using LV_USE_NEMA_VG,
set LV_NEMA_GFX_MAX_RESX and LV_NEMA_GFX_MAX_RESY
to the size of the display you will be using so that enough static
memory will be reserved for VG. Without VG, more task types will be
performed by the software renderer.
"libs/nema_gfx" contains pre-compiled binaries for the NeoChrom GPU drivers.
lv_port_riverdi_stm32u5 is already configured to link the "cortex_m33_revC" binaries when building and lv_port_stm32u5g9j-dk2 is configured to link the "cortex_m33_NemaPVG" binaries when building.
"cortex_m33_revC" works on all STM32 m33 devices with a NeoChrom core while "cortex_m33_NemaPVG" additionally supports the tessellation and matrix multiplication acceleration that the STM32 U5F and U5G NeoChrom cores are capable of.
With a different STM32CubeIDE project, you can configure the libraries to be linked by right-clicking the project in the "Project Explorer" sidebar, clicking "Properties", navigating to "C/C++ Build", "Settings", "MCU G++ Linker", and then "Libraries". Add an entry under "Libraries (-l)" that is "nemagfx-float-abi-hard". Add an entry under "Library search path (-L)" which is a path to "libs/nema_gfx/lib/core/cortex_m33_revC/gcc" e.g. "${workspace_loc:/${ProjName}/Middlewares/LVGL/lvgl/libs/nema_gfx/lib/core/cortex_m33_revC/gcc}". You will also want to add the "libs/nema_gfx/include" directory to your include search paths. Under "MCU GCC Compiler", "Include paths", add an entry to "Include paths (-I)" which is a path to "libs/nema_gfx/include" e.g. "${workspace_loc:/${ProjName}/Middlewares/LVGL/lvgl/libs/nema_gfx/include}". Click "Apply and Close".
Note
cannot find -lnemagfx-float-abi-hard: No such file or directory
The library version for ST was updated to revC so the path component
cortex_m33 must be updated to cortex_m33_revC in STM32CubeIDE.
32 and 16 bit LV_COLOR_DEPTH is supported.
At the time of writing, LV_USE_OS support is experimental
and not yet working in
lv_port_riverdi_stm32u5
NeoChrom requires a simple HAL implementation to allocate memory and optionally
lock resources. You may use a custom HAL implementation for your platform or use one of the
provided implementations by setting LV_USE_NEMA_HAL to a value other than
LV_NEMA_HAL_CUSTOM.
TSC Images¶
The TSC converter can be downloaded from here.
TSC (ThinkSilicon Compression) images can be drawn by this renderer. The
TSC 4/6/6A/12/12A color formats are part of lv_color_format_t.
All other renderers will ignore images with these color formats.
Define an image descriptor variable with the corresponding
TSC color format and the GPU will be able to draw it directly.
Stride does not need to be specified because it will be computed by the
renderer.
const lv_image_dsc_t img_demo_widgets_avatar_tsc6a = {
.header.cf = LV_COLOR_FORMAT_NEMA_TSC6A,
.header.w = 144,
.header.h = 144,
.data = img_demo_widgets_avatar_tsc6a_map,
.data_size = sizeof(img_demo_widgets_avatar_tsc6a_map),
};
Interop with the LTDC driver and the DMA2D Draw Unit¶
NeoChrom can be enabled at the same time as LTDC. They will not interfere with each other at all.
NeoChrom and DMA2D may be enabled at the same time. They are both draw units and they will both independently accept draw tasks.