STM32串口接收大于16位的字符串

在STM32中，串口接收大于16位的字符串需要使用中断方式接收数据，并使用循环缓冲区来存储接收到的数据。以下是一个简单的示例代码，可以接收最多256个字节的数据：

#include "stm32f4xx.h"
#include <stdio.h>
#include <string.h>

#define USART_RX_BUF_SIZE 256

volatile uint8_t usart_rx_buf[USART_RX_BUF_SIZE];
volatile uint16_t usart_rx_buf_head = 0;
volatile uint16_t usart_rx_buf_tail = 0;

void USART2_IRQHandler(void)
{
    if (USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)
    {
        uint8_t data = USART_ReceiveData(USART2);
        uint16_t next_head = (usart_rx_buf_head + 1) % USART_RX_BUF_SIZE;
        if (next_head != usart_rx_buf_tail)
        {
            usart_rx_buf[usart_rx_buf_head] = data;
            usart_rx_buf_head = next_head;
        }
    }
}

int main(void)
{
    // 初始化串口
    USART_InitTypeDef USART_InitStructure;
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);
    USART_InitStructure.USART_BaudRate = 115200;
    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(USART2, &USART_InitStructure);
    USART_Cmd(USART2, ENABLE);

    // 初始化中断
    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = USART2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);

    while (1)
    {
        // 处理接收到的数据
        while (usart_rx_buf_tail != usart_rx_buf_head)
        {
            // 读取一个字节
            uint8_t data = usart_rx_buf[usart_rx_buf_tail];
            usart_rx_buf_tail = (usart_rx_buf_tail + 1) % USART_RX_BUF_SIZE;

            // 处理数据
            printf("Received: %c\n", data);
        }
    }
}

在此示例代码中，我们使用了一个循环缓冲区来存储接收到的数据。当有数据到达时，中断会触发并将数据存储到缓冲区中。然后，我们在主循环中处理缓冲区中的数据。这样可以确保我们不会丢失任何数据，即使数据到达速度非常快。