stm32f4中用SD卡存储DCMI的图像

来源：互联网发布：最新网络歌曲编辑：程序博客网时间：2024/05/22 00:05

因为自己本科做的创新性实验和飞思卡尔小车都是摄像头的，研究生也做的视频处理方向。后来，想做一个小视频监制，闲麻烦，没有用那TI的DM6446，就用的手头stm32f4开发板，由于没有LCD显示屏，我只能直接把DCMI图像保存在内部RAM中，再保存到SD里，在上位机读取SD卡转换成图片，我就用VC+OPENCV。

现在说说做的流程吧。摄像头是买的OV9665 。直接接的是DCMI接口。而SD卡不能接SDIO了，因为我这开发板是100引脚封装的，SDIO和DCMI复用引脚冲突。之后SD卡选用的是SPI接口。

1.关于SPI接口的SD卡读写操作，我在前几篇博客中写过，也附带了写好的FATFS文件系统程序，大家可以参考，我这里就不多写了。

2.重要的是关于DCMI的摄像头接口，主要是在DCMI的配置上和DMA的配置，下面着重进行讲解。

void OV9655_HW_Init(void) {  GPIO_InitTypeDef GPIO_InitStructure;  I2C_InitTypeDef  I2C_InitStruct;  /*** Configures the DCMI GPIOs to interface with the OV9655 camera module ***/  /* Enable DCMI GPIOs clocks */  /* Enable DCMI GPIOs clocks */  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOB | RCC_AHB1Periph_GPIOC |                         RCC_AHB1Periph_GPIOE, ENABLE);   /* Enable DCMI clock */  RCC_AHB2PeriphClockCmd(RCC_AHB2Periph_DCMI, ENABLE);  /* Connect DCMI pins to AF13 ************************************************/  GPIO_PinAFConfig(GPIOA, GPIO_PinSource4, GPIO_AF_DCMI);//HSYNC  GPIO_PinAFConfig(GPIOA, GPIO_PinSource6, GPIO_AF_DCMI);//PIXCLK  GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_DCMI);//DCMI_D5  GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_DCMI);//VSYNC  GPIO_PinAFConfig(GPIOC, GPIO_PinSource6, GPIO_AF_DCMI);//DCMI_D0  GPIO_PinAFConfig(GPIOC, GPIO_PinSource7, GPIO_AF_DCMI);//DCMI_D1  GPIO_PinAFConfig(GPIOE, GPIO_PinSource0, GPIO_AF_DCMI);//DCMI_D2  GPIO_PinAFConfig(GPIOE, GPIO_PinSource1, GPIO_AF_DCMI);//DCMI_D3  GPIO_PinAFConfig(GPIOE, GPIO_PinSource4, GPIO_AF_DCMI);//DCMI_D4  GPIO_PinAFConfig(GPIOE, GPIO_PinSource5, GPIO_AF_DCMI);//DCMI_D6  GPIO_PinAFConfig(GPIOE, GPIO_PinSource6, GPIO_AF_DCMI);//DCMI_D7    /* DCMI GPIO configuration **************************************************/  /* HSYNC(PA4), PIXCLK(PA6) */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_6;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;    GPIO_Init(GPIOA, &GPIO_InitStructure);  /* DCMI_D5(PB6), VSYNC(PB7) */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;    GPIO_Init(GPIOB, &GPIO_InitStructure);  /* DCMI_D0(PC6), DCMI_D1(PC7) */  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;    GPIO_Init(GPIOC, &GPIO_InitStructure);  /* DCMI_D2(PE0), DCMI_D3(PE1), DCMI_D4(PE4), DCMI_D6(PE5), DCMI_D7(PE6),*/  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;    GPIO_Init(GPIOE, &GPIO_InitStructure);    /****** Configures the I2C1 used for OV9655 camera module configuration *****/ /* I2C1 clock enable */  RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);  /* GPIOB clock enable */  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);   /* Connect I2C1 pins to AF4 */  GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_I2C1);  GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1);    /* Configure I2C1 GPIOs */    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;  GPIO_InitStructure.GPIO_OType = GPIO_OType_OD;  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;  GPIO_Init(GPIOB, &GPIO_InitStructure);  /* Configure I2C1 */  /* I2C DeInit */  I2C_DeInit(I2C1);      /* Enable the I2C peripheral */  I2C_Cmd(I2C1, ENABLE);   /* Set the I2C structure parameters */  I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;  I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;  I2C_InitStruct.I2C_OwnAddress1 = 0xFE;  I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;  I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;  I2C_InitStruct.I2C_ClockSpeed = 30000;    /* Initialize the I2C peripheral w/ selected parameters */  I2C_Init(I2C1, &I2C_InitStruct);}

关于DCMI和DMA的初始化程序如下

void OV9655_Init(ImageFormat_TypeDef ImageFormat){  DCMI_InitTypeDef DCMI_InitStructure;  DMA_InitTypeDef  DMA_InitStructure;    /*** Configures the DCMI to interface with the OV9655 camera module ***/  /* Enable DCMI clock */  RCC_AHB2PeriphClockCmd(RCC_AHB2Periph_DCMI, ENABLE);  /* DCMI configuration */   DCMI_InitStructure.DCMI_CaptureMode = DCMI_CaptureMode_SnapShot;//DCMI_CaptureMode_Continuous;  DCMI_InitStructure.DCMI_SynchroMode = DCMI_SynchroMode_Hardware;  DCMI_InitStructure.DCMI_PCKPolarity = DCMI_PCKPolarity_Falling;  DCMI_InitStructure.DCMI_VSPolarity = DCMI_VSPolarity_High;  DCMI_InitStructure.DCMI_HSPolarity = DCMI_HSPolarity_High;  DCMI_InitStructure.DCMI_CaptureRate = DCMI_CaptureRate_1of4_Frame;//DCMI_CaptureRate_All_Frame;  DCMI_InitStructure.DCMI_ExtendedDataMode = DCMI_ExtendedDataMode_8b;  //----- mask interrupt for DCMI -----      DCMI_ITConfig(DCMI_IT_VSYNC, ENABLE);      DCMI_ITConfig(DCMI_IT_LINE, ENABLE);      DCMI_ITConfig(DCMI_IT_FRAME, ENABLE);      DCMI_ITConfig(DCMI_IT_OVF, ENABLE);      DCMI_ITConfig(DCMI_IT_ERR, ENABLE);    /* Configures the DMA2 to transfer Data from DCMI */  /* Enable DMA2 clock */  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_DMA2, ENABLE);    /* DMA2 Stream1 Configuration */  DMA_DeInit(DMA2_Stream1);  DMA_InitStructure.DMA_Channel = DMA_Channel_1;    DMA_InitStructure.DMA_PeripheralBaseAddr = DCMI_DR_ADDRESS;  DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)theMap;//FSMC_LCD_ADDRESS;  DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralToMemory;  DMA_InitStructure.DMA_BufferSize = 9600;  DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;  DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;  DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;  DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;//DMA_MemoryDataSize_HalfWord;  DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;//DMA_Mode_Circular;  DMA_InitStructure.DMA_Priority = DMA_Priority_High;  DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;  DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;  DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;  DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;    //------------------------中断        DMA_ITConfig(DMA2_Stream1, DMA_IT_TC, ENABLE);          DMA_ITConfig(DMA2_Stream1, DMA_IT_HT, ENABLE);           DMA_ITConfig(DMA2_Stream1, DMA_IT_TE, ENABLE);          DMA_ITConfig(DMA2_Stream1, DMA_IT_FE, ENABLE);                     switch(ImageFormat)  {    case BMP_QQVGA:    {      /* DCMI configuration */      DCMI_Init(&DCMI_InitStructure);      /* DMA2 IRQ channel Configuration */      DMA_Init(DMA2_Stream1, &DMA_InitStructure);      break;    }    case BMP_QVGA:    {      /* DCMI configuration */       DCMI_Init(&DCMI_InitStructure);      /* DMA2 IRQ channel Configuration */      DMA_Init(DMA2_Stream1, &DMA_InitStructure);       break;    }    default:    {      /* DCMI configuration */       DCMI_Init(&DCMI_InitStructure);      /* DMA2 IRQ channel Configuration */      DMA_Init(DMA2_Stream1, &DMA_InitStructure);      break;    }  }    }其中DCMI_InitStructure.DCMI_CaptureMode这里选用的是DCMI_CaptureMode_SnapShot，没有选用DCMI_CaptureMode_Continuous，因为程序存将图像存SD里，速度有限，只能采一张，存一张。

所以，只要DCMI_CaptureCmd(ENABLE);DCMI就开始拍照一张，拍完一张后，使能自动关闭。下次要再拍照的时候，重新DCMI_CaptureCmd(ENABLE); 即可。

然后关于DMA，这个配置让我头疼了些时间，主要是对DMA不熟。

DMA_InitStructure.DMA_Mode 用的是 DMA_Mode_Circular模式，因为DCMI用的是单张拍照的，所以这里用DMA_Mode_Circular模式没有问题。

DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;//外设的数据字长,DCMI的寄存器是32位的，所以这里选的word
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;//内存的数据字长，我存图像用的数组是unsigned char类型，所以这里用BYTE。

DMA_InitStructure.DMA_BufferSize = 9600;//关键是这个，因为摄像头设置的图像大小为120*160的，是RGB565格式，一个像素点占两个字节，所以存一幅图像需要38400字节。而这个buffersize是相对于DMA数据源的字长来说的，这里就是对于DCMI的数据寄存器word类型，38400/4=9600;

还有关于上位机软件读取这个文件时的方法，我用的是VC+OPENCV，38400字节中，是每两个字节表示一个像素点的RGB颜色，这两个字节是低字节在前，高字节在后，示意方法如下

for(int i=0; i<Hang*Lie ; i++)
   {
       rgb565 = p[2*i+0] + 256*p[2*i+1];

       b = (rgb565>>0) & 0x001f;
       g = (rgb565>>5) & 0x003f;
       r = (rgb565>>11) & 0x001f;
       b = b<<3;
       g = g<<2;
       r = r<<3;
       vec.push_back(b);
       vec.push_back(g);
       vec.push_back(r);
   }
在OPENCV中存储图像的程序示意如下：

void vecToImage(vector<unsigned char> & vec, IplImage* pImg8u3)
{
   int cnt=0;

   for(int y=0; y<pImg8u3->height; y++)
   {
       unsigned char* ptr = (unsigned char*)(pImg8u3->imageData + y * pImg8u3->widthStep);
       for(int x=0; x<pImg8u3->width; x++)
       {
           *(ptr + 3*x+0) = vec.at(cnt++);
           *(ptr + 3*x+1) = vec.at(cnt++);
           *(ptr + 3*x+2) = vec.at(cnt++);
       }
   }
}

其他的，我就不多说了，程序我上传到资源里，大家可以下载，有问题可以留言。http://download.csdn.net/detail/raoqin/5348148