生成一段代码，实现STM32通过485协议只接收数据0x11,0x22,0x33，之后发送0x44,0x55,0x66

以下是一段示例代码，实现STM32通过485协议只接收数据0x11,0x22,0x33，之后发送0x44,0x55,0x66：

#include "stm32f4xx.h"

#define USARTx USART1
#define USARTx_CLK RCC_APB2Periph_USART1
#define USARTx_IRQn USART1_IRQn
#define USARTx_IRQHandler USART1_IRQHandler

#define GPIOx GPIOA
#define GPIOx_CLK RCC_AHB1Periph_GPIOA
#define GPIOx_PIN_TX GPIO_Pin_9
#define GPIOx_PIN_RX GPIO_Pin_10
#define GPIOx_PIN_DE GPIO_Pin_8

#define RX_BUFFER_SIZE 10

uint8_t rxBuffer[RX_BUFFER_SIZE];
uint8_t rxIndex = 0;

void initUSART(void) {
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;
    
    RCC_AHB1PeriphClockCmd(GPIOx_CLK, ENABLE);
    RCC_APB2PeriphClockCmd(USARTx_CLK, ENABLE);
    
    GPIO_InitStructure.GPIO_Pin = GPIOx_PIN_TX | GPIOx_PIN_RX | GPIOx_PIN_DE;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOx, &GPIO_InitStructure);
    
    GPIO_PinAFConfig(GPIOx, GPIO_PinSource9, GPIO_AF_USART1);
    GPIO_PinAFConfig(GPIOx, GPIO_PinSource10, GPIO_AF_USART1);
    
    USART_InitStructure.USART_BaudRate = 9600;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
    USART_Init(USARTx, &USART_InitStructure);
    
    USART_ITConfig(USARTx, USART_IT_RXNE, ENABLE);
    
    USART_DirectionModeCmd(USARTx, USART_Mode_Tx, ENABLE);
    USART_DirectionModeCmd(USARTx, USART_Mode_Rx, ENABLE);
    
    USART_Cmd(USARTx, ENABLE);
}

void USARTx_IRQHandler(void) {
    if (USART_GetITStatus(USARTx, USART_IT_RXNE) != RESET) {
        uint8_t data = USART_ReceiveData(USARTx);
        
        if (data == 0x11 || data == 0x22 || data == 0x33) {
            rxBuffer[rxIndex++] = data;
            
            if (rxIndex == RX_BUFFER_SIZE) {
                rxIndex = 0;
            }
        }
    }
}

void sendData(void) {
    USART_DirectionModeCmd(USARTx, USART_Mode_Tx, ENABLE);
    
    USART_SendData(USARTx, 0x44);
    while (USART_GetFlagStatus(USARTx, USART_FLAG_TC) == RESET);
    
    USART_SendData(USARTx, 0x55);
    while (USART_GetFlagStatus(USARTx, USART_FLAG_TC) == RESET);
    
    USART_SendData(USARTx, 0x66);
    while (USART_GetFlagStatus(USARTx, USART_FLAG_TC) == RESET);
    
    USART_DirectionModeCmd(USARTx, USART_Mode_Tx, DISABLE);
}

int main(void) {
    initUSART();
    
    while (1) {
        if (rxBuffer[0] == 0x11 && rxBuffer[1] == 0x22 && rxBuffer[2] == 0x33) {
            sendData();
        }
    }
}