STM32 uart 中断fifo 收发例程 标准库

下面是一个基于STM32标准库的UART中断FIFO收发例程：

#include "stm32f10x.h"
#include <stdio.h>

#define RX_BUFFER_SIZE 128
#define TX_BUFFER_SIZE 128

volatile uint8_t rx_buffer[RX_BUFFER_SIZE];
volatile uint8_t tx_buffer[TX_BUFFER_SIZE];
volatile uint8_t rx_buffer_head = 0;
volatile uint8_t rx_buffer_tail = 0;
volatile uint8_t tx_buffer_head = 0;
volatile uint8_t tx_buffer_tail = 0;
volatile uint8_t tx_busy = 0;

void USART1_IRQHandler(void)
{
    // Check if data received
    if (USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)
    {
        // Read data from the USART and put it into the RX buffer
        uint8_t data = USART_ReceiveData(USART1);
        uint8_t next_head = (rx_buffer_head + 1) % RX_BUFFER_SIZE;
        if (next_head != rx_buffer_tail)
        {
            rx_buffer[rx_buffer_head] = data;
            rx_buffer_head = next_head;
        }
    }

    // Check if data transmitted
    if (USART_GetITStatus(USART1, USART_IT_TXE) != RESET)
    {
        // Send the next byte from the TX buffer
        if (tx_buffer_head != tx_buffer_tail)
        {
            USART_SendData(USART1, tx_buffer[tx_buffer_tail]);
            tx_buffer_tail = (tx_buffer_tail + 1) % TX_BUFFER_SIZE;
        }
        else
        {
            // Disable the USART TX empty interrupt if the TX buffer is empty
            USART_ITConfig(USART1, USART_IT_TXE, DISABLE);
            tx_busy = 0;
        }
    }
}

void USART1_Init(void)
{
    USART_InitTypeDef USART_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    // Enable the USART1 peripheral
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);

    // Configure the USART1 pins
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    // Configure the USART1 peripheral
    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(USART1, &USART_InitStructure);

    // Enable the USART1 interrupt
    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    // Enable the USART1 peripheral
    USART_Cmd(USART1, ENABLE);
}

void USART1_Send(uint8_t *data, uint16_t length)
{
    while (tx_busy);
    tx_busy = 1;
    for (uint16_t i = 0; i < length; i++)
    {
        uint8_t next_head = (tx_buffer_head + 1) % TX_BUFFER_SIZE;
        if (next_head != tx_buffer_tail)
        {
            tx_buffer[tx_buffer_head] = data[i];
            tx_buffer_head = next_head;
        }
        else
        {
            // TX buffer is full, wait for space to become available
            while (next_head == tx_buffer_tail);
            tx_buffer[tx_buffer_head] = data[i];
            tx_buffer_head = next_head;
        }
    }
    USART_ITConfig(USART1, USART_IT_TXE, ENABLE);
}

uint8_t USART1_ReadByte(void)
{
    if (rx_buffer_head == rx_buffer_tail)
    {
        return 0; // RX buffer is empty
    }
    uint8_t data = rx_buffer[rx_buffer_tail];
    rx_buffer_tail = (rx_buffer_tail + 1) % RX_BUFFER_SIZE;
    return data;
}

int main(void)
{
    USART1_Init();

    while (1)
    {
        // Read and echo any data received
        uint8_t data = USART1_ReadByte();
        if (data != 0)
        {
            USART1_Send(&data, 1);
        }
    }
}

在此示例中，我们将接收到的数据存储在一个循环队列（FIFO）中，并在需要发送数据时将数据存储在另一个队列中。在每个USART中断中，我们检查是否有数据可用于接收和发送。如果有，我们将数据读入和写入适当的队列中。如果发送队列为空，则禁用USART的TX空中断。在主循环中，我们读取接收队列中的任何数据并将其回传。