编写STM32f103c8t6驱动OV5640的程序

以下是一个简单的OV5640驱动程序，假设OV5640连接到STM32f103c8t6的I2C1和DCMI接口。

#include "stm32f10x.h"
#include "ov5640.h"

#define I2C_SPEED       100000
#define I2C_SLAVE_ADDR  0x78

#define DCMI_FIFO_SIZE  640*480*2

uint8_t dcmi_fifo[DCMI_FIFO_SIZE];

void OV5640_Init(void)
{
    // 初始化I2C1
    I2C_InitTypeDef i2c_init;
    i2c_init.I2C_ClockSpeed = I2C_SPEED;
    i2c_init.I2C_Mode = I2C_Mode_I2C;
    i2c_init.I2C_DutyCycle = I2C_DutyCycle_2;
    i2c_init.I2C_OwnAddress1 = 0;
    i2c_init.I2C_Ack = I2C_Ack_Enable;
    i2c_init.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_Init(I2C1, &i2c_init);
    I2C_Cmd(I2C1, ENABLE);

    // 初始化DCMI
    DCMI_InitTypeDef dcmi_init;
    dcmi_init.DCMI_CaptureMode = DCMI_CaptureMode_SnapShot;
    dcmi_init.DCMI_SynchroMode = DCMI_SynchroMode_Hardware;
    dcmi_init.DCMI_PCKPolarity = DCMI_PCKPolarity_Falling;
    dcmi_init.DCMI_VSPolarity = DCMI_VSPolarity_Low;
    dcmi_init.DCMI_HSPolarity = DCMI_HSPolarity_Low;
    dcmi_init.DCMI_CaptureRate = DCMI_CaptureRate_All_Frame;
    dcmi_init.DCMI_ExtendedDataMode = DCMI_ExtendedDataMode_8b;
    DCMI_Init(&dcmi_init);

    // 初始化OV5640
    // ...

    // 配置DMA
    DMA_InitTypeDef dma_init;
    dma_init.DMA_PeripheralBaseAddr = (uint32_t)&(DCMI->DR);
    dma_init.DMA_MemoryBaseAddr = (uint32_t)dcmi_fifo;
    dma_init.DMA_DIR = DMA_DIR_PeripheralSRC;
    dma_init.DMA_BufferSize = DCMI_FIFO_SIZE / 4;
    dma_init.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
    dma_init.DMA_MemoryInc = DMA_MemoryInc_Enable;
    dma_init.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
    dma_init.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
    dma_init.DMA_Mode = DMA_Mode_Circular;
    dma_init.DMA_Priority = DMA_Priority_High;
    dma_init.DMA_M2M = DMA_M2M_Disable;
    DMA_Init(DMA2_Channel1, &dma_init);

    // 配置NVIC
    NVIC_InitTypeDef nvic_init;
    nvic_init.NVIC_IRQChannel = DMA2_Channel1_IRQn;
    nvic_init.NVIC_IRQChannelPreemptionPriority = 0;
    nvic_init.NVIC_IRQChannelSubPriority = 0;
    nvic_init.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&nvic_init);

    // 启动DMA
    DMA_ITConfig(DMA2_Channel1, DMA_IT_TC, ENABLE);
    DMA_Cmd(DMA2_Channel1, ENABLE);

    // 启动DCMI
    DCMI_Cmd(ENABLE);
    DCMI_CaptureCmd(ENABLE);
}

void OV5640_ReadFrame(uint16_t* buffer)
{
    // 等待DMA传输结束
    while (DMA_GetITStatus(DMA2_IT_TC1) == RESET);

    // 将DCMI FIFO中的数据转换为RGB565格式的像素数据
    for (int i = 0; i < DCMI_FIFO_SIZE / 2; i++)
    {
        uint8_t low = dcmi_fifo[i * 2];
        uint8_t high = dcmi_fifo[i * 2 + 1];
        buffer[i] = (high << 8) | low;
    }

    // 清空DMA传输完成标志
    DMA_ClearITPendingBit(DMA2_IT_TC1);
}

void DMA2_Channel1_IRQHandler(void)
{
    DMA_ClearITPendingBit(DMA2_IT_TC1);
}

需要注意的是，以上代码只是一个简单的框架，具体的OV5640驱动实现需要根据OV5640的数据手册进行编写，同时需要根据具体的应用场景来决定如何使用读取到的图像数据。