使用CT117E-M4开发板HAL库编写一份调用ov7670的代码在LCD屏幕显示实时图像的代码

由于ov7670摄像头输出的是模拟信号，需要使用ADC模块将其转换为数字信号，然后通过DMA传输到SRAM中，最后使用LCD模块将图像显示在屏幕上。以下是一个基本的示例代码：

#include "stm32f1xx_hal.h"

#define WIDTH 320
#define HEIGHT 240

ADC_HandleTypeDef hadc1;
DMA_HandleTypeDef hdma_adc1;
DMA_HandleTypeDef hdma_memtomem_dma1_channel1;
LTDC_HandleTypeDef hltdc;

uint16_t frame_buffer[WIDTH * HEIGHT];

void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_DMA_Init(void);
static void MX_ADC1_Init(void);
static void MX_LTDC_Init(void);

int main(void)
{
  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_ADC1_Init();
  MX_LTDC_Init();

  HAL_ADC_Start_DMA(&hadc1, (uint32_t *)frame_buffer, WIDTH * HEIGHT);

  while (1) {}
}

void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_ADC1_Init(void)
{
  ADC_ChannelConfTypeDef sConfig = {0};

  hadc1.Instance = ADC1;
  hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;
  hadc1.Init.ContinuousConvMode = ENABLE;
  hadc1.Init.DiscontinuousConvMode = DISABLE;
  hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc1.Init.NbrOfConversion = 1;
  if (HAL_ADC_Init(&hadc1) != HAL_OK)
  {
    Error_Handler();
  }

  sConfig.Channel = ADC_CHANNEL_0;
  sConfig.Rank = ADC_REGULAR_RANK_1;
  sConfig.SamplingTime = ADC_SAMPLETIME_239CYCLES_5;
  if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
}

static void MX_DMA_Init(void)
{
  __HAL_RCC_DMA1_CLK_ENABLE();

  HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);

  HAL_NVIC_SetPriority(DMA1_Channel2_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Channel2_IRQn);

  HAL_NVIC_SetPriority(DMA2_Channel1_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA2_Channel1_IRQn);

  hdma_adc1.Instance = DMA1_Channel1;
  hdma_adc1.Init.Direction = DMA_PERIPH_TO_MEMORY;
  hdma_adc1.Init.PeriphInc = DMA_PINC_DISABLE;
  hdma_adc1.Init.MemInc = DMA_MINC_ENABLE;
  hdma_adc1.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
  hdma_adc1.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
  hdma_adc1.Init.Mode = DMA_CIRCULAR;
  hdma_adc1.Init.Priority = DMA_PRIORITY_LOW;
  if (HAL_DMA_Init(&hdma_adc1) != HAL_OK)
  {
    Error_Handler();
  }

  __HAL_DMA1_REMAP(HAL_DMA1_CH1_ADC);

  __HAL_LINKDMA(&hadc1, DMA_Handle, hdma_adc1);

  hdma_memtomem_dma1_channel1.Instance = DMA1_Channel1;
  hdma_memtomem_dma1_channel1.Init.Direction = DMA_MEMORY_TO_MEMORY;
  hdma_memtomem_dma1_channel1.Init.PeriphInc = DMA_PINC_ENABLE;
  hdma_memtomem_dma1_channel1.Init.MemInc = DMA_MINC_ENABLE;
  hdma_memtomem_dma1_channel1.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;
  hdma_memtomem_dma1_channel1.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;
  hdma_memtomem_dma1_channel1.Init.Mode = DMA_NORMAL;
  hdma_memtomem_dma1_channel1.Init.Priority = DMA_PRIORITY_LOW;
  if (HAL_DMA_Init(&hdma_memtomem_dma1_channel1) != HAL_OK)
  {
    Error_Handler();
  }

  __HAL_LINKDMA(&hltdc, DMA2D_Handle, hdma_memtomem_dma1_channel1);
}

static void MX_LTDC_Init(void)
{
  LTDC_LayerCfgTypeDef pLayerCfg = {0};
  LTDC_InitStructTypeDef LTDC_InitStruct = {0};

  __HAL_RCC_LTDC_CLK_ENABLE();

  HAL_NVIC_SetPriority(LTDC_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(LTDC_IRQn);

  LTDC_InitStruct.HorizontalSync = 1;
  LTDC_InitStruct.VerticalSync = 1;
  LTDC_InitStruct.AccumulatedHBP = 41;
  LTDC_InitStruct.AccumulatedVBP = 10;
  LTDC_InitStruct.AccumulatedActiveW = 361;
  LTDC_InitStruct.AccumulatedActiveH = 250;
  LTDC_InitStruct.TotalWidth = 408;
  LTDC_InitStruct.TotalHeigh = 260;
  LTDC_InitStruct.Backcolor.Blue = 0;
  LTDC_InitStruct.Backcolor.Green = 0;
  LTDC_InitStruct.Backcolor.Red = 0;
  if (HAL_LTDC_Init(&hltdc, &LTDC_InitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  pLayerCfg.WindowX0 = 0;
  pLayerCfg.WindowX1 = WIDTH - 1;
  pLayerCfg.WindowY0 = 0;
  pLayerCfg.WindowY1 = HEIGHT - 1;
  pLayerCfg.PixelFormat = LTDC_PIXEL_FORMAT_RGB565;
  pLayerCfg.Alpha = 255;
  pLayerCfg.Alpha0 = 0;
  pLayerCfg.BlendingFactor1 = LTDC_BLENDING_FACTOR1_CA;
  pLayerCfg.BlendingFactor2 = LTDC_BLENDING_FACTOR2_CA;
  pLayerCfg.FBStartAdress = (uint32_t)&frame_buffer;
  pLayerCfg.ImageWidth = WIDTH;
  pLayerCfg.ImageHeight = HEIGHT;
  pLayerCfg.Backcolor.Blue = 0;
  pLayerCfg.Backcolor.Green = 0;
  pLayerCfg.Backcolor.Red = 0;
  if (HAL_LTDC_ConfigLayer(&hltdc, &pLayerCfg, 0) != HAL_OK)
  {
    Error_Handler();
  }

  HAL_LTDC_EnableDither(&hltdc);
  HAL_LTDC_EnableColorKeying(&hltdc, 0);
}

void Error_Handler(void)
{
  while (1) {}
}

void DMA1_Channel1_IRQHandler(void)
{
  HAL_DMA_IRQHandler(&hdma_adc1);
}

void DMA2_Channel1_IRQHandler(void)
{
  HAL_DMA_IRQHandler(&hdma_memtomem_dma1_channel1);
}

void LTDC_IRQHandler(void)
{
  HAL_LTDC_IRQHandler(&hltdc);
}

需要注意的是，此代码并未包含ov7670的初始化和配置，需要根据实际情况进行添加。