99 lines
4.3 KiB
Plaintext
99 lines
4.3 KiB
Plaintext
/**
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@page LTDC_Display_2Layers LTDC Display 2 Layers example
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@verbatim
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******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
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* @file LTDC/LTDC_Display_2Layers/readme.txt
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* @author MCD Application Team
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* @brief Description of the LTDC Display 2 Layers example.
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******************************************************************************
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* @attention
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*
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* Copyright (c) 2017 STMicroelectronics.
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* 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
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* in the root directory of this software component.
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* If no LICENSE file comes with this software, it is provided AS-IS.
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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How to configure the LTDC peripheral to display two layers at the same time.
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The goal of this example is to explain how to blend two layers and how to display
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an image with L8 (8bits per pixels indexed) as pixel format.
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At the beginning of the main program the HAL_Init() function is called to reset
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all the peripherals, initialize the Flash interface and the systick.
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Then the SystemClock_Config() function is used to configure the system
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clock (SYSCLK) to run at 180 MHz.
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After LCD initialization, the LCD layer 1 and Layer 2 are configured as following :
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- Layer 1 is configured to display an image loaded from flash memory with direct
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color (RGB565) as pixel format and 240x160 size.
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- Layer 2 is configured to display an image loaded from flash memory with direct
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color (RGB565) as pixel format and 240x160 size.
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The blending is always active and the two layers can be blended following
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the configured blending factors and the constant alpha.
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In this example the constant alpha for layer 2 is decreased to see the layer 1
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in the intersection zone.
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The images change unlike their positions on LCD in an infinite loop.
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@note :
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The C files of the images used in this example are generated with
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STemWin bitmap converter released with this package.
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\Middlewares\ST\STemWin\Software\BmpCvtST.exe
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Use the bitmap files under resources repository
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STM32 Discovery boards LED can be used to monitor the transfer status:
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- LED3 is ON when there is an error in Init process.
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@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
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based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
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a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
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than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
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To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
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@note The application needs to ensure that the SysTick time base is always set to 1 millisecond
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to have correct HAL operation.
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@par Keywords
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Display, LTDC, Display Controller, TFT, LCD, Graphic, RGB888, 2 Layers, BMP
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@par Directory contents
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- LTDC/LTDC_Display_2Layers/Inc/main.h Main configuration file
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- LTDC/LTDC_Display_2Layers/Inc/stm32f4xx_it.h Interrupt handlers header file
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- LTDC/LTDC_Display_2Layers/Inc/stm32f4xx_hal_conf.h HAL configuration file
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- LTDC/LTDC_Display_2Layers/Inc/st_logo1.h Image used for LTDC Validation
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- LTDC/LTDC_Display_2Layers/Inc/st_logo2.h Image used for LTDC Validation
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- LTDC/LTDC_Display_2Layers/Src/main.c Main program
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- LTDC/LTDC_Display_2Layers/Src/stm32f4xx_it.c Interrupt handlers
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- LTDC/LTDC_Display_2Layers/Src/stm32f4xx_hal_msp.c HAL MSP module
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- LTDC/LTDC_Display_2Layers/Src/system_stm32f4xx.c STM32F4xx system clock configuration file
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@par Hardware and Software environment
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- This example runs on STM32F429xx devices.
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- This example has been tested with STMicroelectronics STM32F429I-Discovery RevC
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boards and can be easily tailored to any other supported device
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and development board.
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@par How to use it ?
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In order to make the program work, you must do the following :
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- Open your preferred toolchain
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- Rebuild all files and load your image into target memory
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- Run the example
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*/
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