STM32标准库 UART FIFO收发例程

好的，以下是一个基于STM32标准库的UART FIFO收发例程：

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

#define UART_BUFFER_SIZE 128

uint8_t uart_rx_buffer[UART_BUFFER_SIZE];
uint8_t uart_tx_buffer[UART_BUFFER_SIZE];

uint8_t uart_rx_data = 0;
uint8_t uart_rx_data_available = 0;

void USART2_IRQHandler(void)
{
    if (USART_GetITStatus(USART2, USART_IT_RXNE) != RESET)
    {
        // Check if receive buffer is full
        if (uart_rx_data_available < UART_BUFFER_SIZE)
        {
            uart_rx_buffer[uart_rx_data_available++] = USART_ReceiveData(USART2);
        }
        else
        {
            uart_rx_data_available = 0;
        }
    }
    if (USART_GetITStatus(USART2, USART_IT_TXE) != RESET)
    {
        if (uart_tx_buffer[0] != 0)
        {
            USART_SendData(USART2, uart_tx_buffer[0]);
            for (uint8_t i = 0; i < UART_BUFFER_SIZE - 1; i++)
            {
                uart_tx_buffer[i] = uart_tx_buffer[i + 1];
            }
            uart_tx_buffer[UART_BUFFER_SIZE - 1] = 0;
        }
        else
        {
            USART_ITConfig(USART2, USART_IT_TXE, DISABLE);
        }
    }
}

void UART_Init()
{
    GPIO_InitTypeDef GPIO_InitStructure;
    USART_InitTypeDef USART_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART2, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2 | GPIO_Pin_3;
    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(GPIOA, &GPIO_InitStructure);

    GPIO_PinAFConfig(GPIOA, GPIO_PinSource2, GPIO_AF_USART2);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource3, GPIO_AF_USART2);

    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_ITConfig(USART2, USART_IT_RXNE, ENABLE);

    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_Cmd(USART2, ENABLE);
}

void UART_Send(const uint8_t *data, uint16_t size)
{
    if (size > UART_BUFFER_SIZE)
    {
        size = UART_BUFFER_SIZE;
    }
    memcpy(uart_tx_buffer, data, size);
    USART_ITConfig(USART2, USART_IT_TXE, ENABLE);
}

uint8_t UART_Read()
{
    if (uart_rx_data_available == 0)
    {
        return 0;
    }
    uint8_t data = uart_rx_buffer[0];
    uart_rx_data_available--;
    for (uint8_t i = 0; i < uart_rx_data_available; i++)
    {
        uart_rx_buffer[i] = uart_rx_buffer[i + 1];
    }
    return data;
}

void UART_ReadBuffer(uint8_t *buffer, uint16_t size)
{
    if (uart_rx_data_available < size)
    {
        size = uart_rx_data_available;
    }
    for (uint16_t i = 0; i < size; i++)
    {
        buffer[i] = uart_rx_buffer[i];
    }
    uart_rx_data_available -= size;
    for (uint16_t i = 0; i < uart_rx_data_available; i++)
    {
        uart_rx_buffer[i] = uart_rx_buffer[i + size];
    }
}

int main(void)
{
    UART_Init();

    while (1)
    {
        uint8_t data = UART_Read();
        if (data != 0)
        {
            // Handle received data
        }
        // Do other stuff
    }
}

这个例程同样使用了UART2，可以根据需要修改。数据接收和发送都使用了中断，相对于轮询模式，可以更快地响应数据，不会占用过多CPU时间。UART_Send函数使用了memcpy函数，也可以使用for循环逐个拷贝实现，但是memcpy函数更加高效。