写一段基于stm32F405光流模块的初始化的代码

以下是基于stm32F405光流模块的初始化代码示例：

#include "stm32f4xx.h"
#include "i2c.h"
#include "optical_flow.h"

#define OF_ADDRESS 0x42

void optical_flow_init(void)
{
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);

    GPIO_InitTypeDef GPIO_InitStruct;
    GPIO_StructInit(&GPIO_InitStruct);
    GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_9;
    GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStruct.GPIO_OType = GPIO_OType_OD;
    GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOB, &GPIO_InitStruct);

    GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_I2C1);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_I2C1);

    I2C_InitTypeDef I2C_InitStruct;
    I2C_StructInit(&I2C_InitStruct);
    I2C_InitStruct.I2C_ClockSpeed = 400000;
    I2C_InitStruct.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStruct.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStruct.I2C_OwnAddress1 = 0x00;
    I2C_InitStruct.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStruct.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_Init(I2C1, &I2C_InitStruct);

    I2C_Cmd(I2C1, ENABLE);

    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));

    I2C_Send7bitAddress(I2C1, OF_ADDRESS, I2C_Direction_Transmitter);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));

    I2C_SendData(I2C1, 0x00);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));

    I2C_GenerateSTOP(I2C1, ENABLE);

    delay_ms(10);
}

在这个例子中，我们使用了stm32f4xx的库函数，同时也需要外部的I2C和optical_flow库文件。这个代码片段初始化了I2C和optical_flow模块，并确保模块已经准备好与处理器通信。