stm32串口和定时器冲突

Question

串口和定时器冲突
发现只要定时器初始化，串口就完全不能用了，怎么办。
下面是初始化代码

void Timer_Init(void)
{
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE);
    
    TIM_InternalClockConfig(TIM4);//调用内部时钟
    
    TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
    TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
    TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up;
    TIM_TimeBaseInitStructure.TIM_Period=5000-1;   //自动重装（计多少数）
    TIM_TimeBaseInitStructure.TIM_Prescaler=720-1;  //预分频
    TIM_TimeBaseInitStructure.TIM_RepetitionCounter=0;
    TIM_TimeBaseInit(TIM4,&TIM_TimeBaseInitStructure);
    
    TIM_ITConfig(TIM4,TIM_IT_Update,ENABLE);
    
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
    
    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel=TIM4_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=2;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;
    NVIC_Init(&NVIC_InitStructure);
    
    TIM_Cmd(TIM4,ENABLE);
}

#include "stm32f10x.h"                  // Device header
#include <stdio.h>
#include <stdarg.h>

char Serial_RxPacket[100];                //"@MSG\r\n"
uint8_t Serial_RxFlag;

void Serial_Init(void)
{
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    
    USART_InitTypeDef USART_InitStructure;
    USART_InitStructure.USART_BaudRate = 9600;
    USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
    USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
    USART_InitStructure.USART_Parity = USART_Parity_No;
    USART_InitStructure.USART_StopBits = USART_StopBits_1;
    USART_InitStructure.USART_WordLength = USART_WordLength_8b;
    USART_Init(USART1, &USART_InitStructure);
    
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
    
    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
    
    NVIC_InitTypeDef NVIC_InitStructure;
    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
    NVIC_Init(&NVIC_InitStructure);
    
    USART_Cmd(USART1, ENABLE);
}

void Serial_SendByte(uint8_t Byte)
{
    USART_SendData(USART1, Byte);
    while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
}

void Serial_SendArray(uint8_t *Array, uint16_t Length)
{
    uint16_t i;
    for (i = 0; i < Length; i ++)
    {
        Serial_SendByte(Array[i]);
    }
}

void Serial_SendString(char *String)
{
    uint8_t i;
    for (i = 0; String[i] != '\0'; i ++)
    {
        Serial_SendByte(String[i]);
    }
}

uint32_t Serial_Pow(uint32_t X, uint32_t Y)
{
    uint32_t Result = 1;
    while (Y --)
    {
        Result *= X;
    }
    return Result;
}

void Serial_SendNumber(uint32_t Number, uint8_t Length)
{
    uint8_t i;
    for (i = 0; i < Length; i ++)
    {
        Serial_SendByte(Number / Serial_Pow(10, Length - i - 1) % 10 + '0');
    }
}

int fputc(int ch, FILE *f)
{
    Serial_SendByte(ch);
    return ch;
}

void Serial_Printf(char *format, ...)
{
    char String[100];
    va_list arg;
    va_start(arg, format);
    vsprintf(String, format, arg);
    va_end(arg);
    Serial_SendString(String);
}

void USART1_IRQHandler(void)
{
    static uint8_t RxState = 0;
    static uint8_t pRxPacket = 0;
    if (USART_GetITStatus(USART1, USART_IT_RXNE) == SET)
    {
        uint8_t RxData = USART_ReceiveData(USART1);
        
        if (RxState == 0)
        {
            if (RxData == '@' && Serial_RxFlag == 0)
            {
                RxState = 1;
                pRxPacket = 0;
            }
        }
        else if (RxState == 1)
        {
            if (RxData == '\r')
            {
                RxState = 2;
            }
            else
            {
                Serial_RxPacket[pRxPacket] = RxData;
                pRxPacket ++;
            }
        }
        else if (RxState == 2)
        {
            if (RxData == '\n')
            {
                RxState = 0;
                Serial_RxPacket[pRxPacket] = '\0';
                Serial_RxFlag = 1;
            }
        }
        
        USART_ClearITPendingBit(USART1, USART_IT_RXNE);
    }
}

Answer 1

以下回复参考：皆我百晓生、券券喵儿等免费微信小程序作答:

你的问题似乎出在定时器中断和串口中断之间的冲突上。当定时器初始化后，串口接收中断似乎不再工作。这可能是因为在定时器中断中，一些寄存器的状态或优先级设置改变了，导致串口接收中断无法正常执行。

解决此问题的一种方法是尝试优化你的中断服务函数（ISR）的实现。另一个可能的问题在于中断优先级配置。STM32的中断优先级可以通过NVIC（嵌套向量中断控制器）配置，确保你的串口中断优先级高于定时器中断。你可以检查并确认这一点：在NVIC初始化部分，USART的中断优先级应该高于TIM的中断优先级。以下是一个可能的配置示例：

NVIC_InitTypeDef NVIC_InitStructure;
// Configure USART1 priority
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; // Highest priority
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_Init(&NVIC_InitStructure);

// Configure TIM4 priority (lower than USART1)
NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; // Lower priority than USART1
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_Init(&NVIC_InitStructure);

此外，尝试暂时移除定时器相关的代码，只留下串口相关的代码进行测试，确保串口能正常工作。然后再逐一添加定时器相关的代码进行测试，以确定问题的具体位置。同时，确保你的定时器配置不会导致它过于频繁地触发中断，这可能干扰到串口接收过程。尝试更改定时器的计数周期或预分频值，看看是否能解决问题。如果可能的话，检查你的单片机型号是否支持并行运行多个中断而不发生冲突。某些单片机可能在设计上不支持并行运行多个中断，或者需要特定的配置才能支持。