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/**
@page LCD_PicturesFromSDCard LCD pictures from SD card application
@verbatim
******************************************************************************
* @file Display/LCD_PicturesFromSDCard/readme.txt
* @author MCD Application Team
* @brief Description of the LCD pictures from SD card application.
******************************************************************************
*
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* @attention
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*
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* Copyright (c) 2017 STMicroelectronics.
* All rights reserved.
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*
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* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
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*
******************************************************************************
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@endverbatim
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@par Application Description
This application describes how to display pictures on LCD saved under SD card.
Prior to starting the application, the user has to create a "/Media" directory under the micro SD card root and
copy the pictures stored in PC directory "/Utilities/Media/Pictures".
@note : The user can add pictures of his choice but the file type, resolution
and pixel format described below must be respected.
Once the LCD, SD card and file systems initialized and configured,
a content check of the "Media" directory is done and the number of ".BMP" files
is retained.
LED1(Red Led) is ON when the uSD disk I/O driver is not Linked correctly.
@note : An associate LCD driver is used in this application
@note : The maximum number of BMP files is fixed to 25. It can be raised
until reaching the maximum of SD card memory space.
The following steps are performed to display all the images stored in the
SD Card :
Step1 :
------
The foreground layer is set, the image copied from SD card to intermediate
SDRAM memory and then copied to LCD frame buffer. The image is fully visible when
the level of transparency is increased until it becomes totally opaque (reaches 255).
Step2 :
------
The transparency of the foreground layer
begins to decrease until becoming totally transparent and the background layer
is set, the image copied from SD card to intermediate SDRAM memory and then
copied to LCD frame buffer and finally the level of transparency of the
background layer increases until it reaches 255 (totally opaque).
Step3 :
------
The transparency of the background layer
begins to decrease until becoming totally transparent and return to step1.
=> A delay of 10 ms is inserted between the three steps.
@note the system clock (SYSCLK) is configured to run at 200 MHz and 50 MHz is provided
at the output PLL divided by PLL_Q. This frequency permits to reach 25 MHz clock
needed for SD operation and in line with microSD specification.
@note
=> If the "Media" directory is empty, a warning message is displayed on
the LCD : " No Bitmap files... "
=> If the file type stored in the "Media" directory is not supported,
a warning message is displayed on the LCD : " No Bitmap files... "
=> If the SD card is removed while running the application, no warning message
is displayed on the LCD. A reset is needed.
=> If no SD card is dtected, a warning message is displayed on the
LCD : " No Bitmap files... ".
@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
@note The application needs to ensure that the SysTick time base is always set to 1 millisecond
to have correct HAL operation.
@note The STM32F7xx devices can reach a maximum clock frequency of 216MHz but as this application uses SDRAM,
the system clock is limited to 200MHz. Indeed proper functioning of the SDRAM is only guaranteed
at a maximum system clock frequency of 200MHz.
@par Keywords
Graphic, Display, LCD, Pictures, SD Card, BMP, RGB565, RGB888, ARGB8888
@Note<74> If the user code size exceeds the DTCM-RAM size or starts from internal cacheable memories (SRAM1 and SRAM2),that is shared between several processors,
<20> <> <EFBFBD> <EFBFBD> <EFBFBD> then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
<EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> The address and the size of cacheable buffers (shared between CPU and other masters) must be properly updated to be aligned to cache line size (32 bytes).
@Note It is recommended to enable the cache and maintain its coherence, but depending on the use case
<EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
<EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
<EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> Even though the user must manage the cache coherence for read accesses.
<EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> Please refer to the AN4838 <20> Managing memory protection unit (MPU) in STM32 MCUs<55>
<EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> <EFBFBD> Please refer to the AN4839 <20> Level 1 cache on STM32F7 Series<65>
@par Directory contents
- Display/LCD_PicturesFromSDCard/Inc/main.h Main configuration file
- Display/LCD_PicturesFromSDCard/Inc/stm32f7xx_it.h Interrupt handlers header file
- Display/LCD_PicturesFromSDCard/Inc/stm32f7xx_hal_conf.h HAL Configuration file
- Display/LCD_PicturesFromSDCard/Inc/ffconf.h FAT file system module configuration file
- Display/LCD_PicturesFromSDCard/Inc/fatfs_storage.h Header for fatfs_storage.c
- Display/LCD_PicturesFromSDCard/Src/sd_diskio.h SD interface with Fatfs header file
- Display/LCD_PicturesFromSDCard/Src/main.c Main program
- Display/LCD_PicturesFromSDCard/Src/fatfs_storage.c Storage (FatFs) driver
- Display/LCD_PicturesFromSDCard/Src/stm32f7xx_it.c Interrupt handlers
- Display/LCD_PicturesFromSDCard/Src/system_stm32f7xx.c STM32F7xx system clock configuration file
- Display/LCD_PicturesFromSDCard/Src/sd_diskio.c SD interface with Fatfs source file
@par Hardware and Software environment
- This application runs on STM32F769xx/STM32F779xx devices.
- This application has been tested with STMicroelectronics STM32F769I-Discovery
boards and can be easily tailored to any other supported device
and development board.
- STM32F769I-Discovery Set-up
- Plug a micro SD card into CN5 connector
@par How to use it ?
In order to make the program work, you must do the following :
- The bitmap images, available under ".Media/"
should be copied inside a dedicated directory named "Media" at the micro SD card root.
The images should have the following properties:
file type : *.bmp
resolution : up to 800x480
pixel format : RGB565, RGB888 or ARGB8888
- Open your preferred toolchain
- Rebuild all files and load your image into target memory
- Run the application
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*/
