用外部中断四个按键分别控制四组跑马灯，基于STM32F103R6

本文将介绍如何使用STM32F103R6外部中断控制四组跑马灯。

步骤：

1. 硬件连接：

将四个按键分别连接到STM32F103R6的四个外部中断引脚，同时将四组跑马灯连接到GPIO口。

2. 代码实现：

首先需要初始化外部中断，设置中断优先级和触发方式，具体代码如下：

void EXTI_Config(void)
{
    EXTI_InitTypeDef EXTI_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    /* Enable GPIOA clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);

    /* Configure PA0, PA1, PA2 and PA3 as input with pull-up */
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    /* Connect EXTI0-3 Line to PA0-3 pin */
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource1);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource2);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource3);

    /* Configure EXTI0-3 */
    EXTI_InitStructure.EXTI_Line = EXTI_Line0 | EXTI_Line1 | EXTI_Line2 | EXTI_Line3;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);

    /* Enable and set EXTI0-3 Interrupt to the highest priority */
    NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x03;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

然后需要编写中断处理函数，在中断函数中实现跑马灯的控制，具体代码如下：

void EXTI0_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line0) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line0);

        // Control the first group of running lights
        // ...

    }
}

void EXTI1_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line1) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line1);

        // Control the second group of running lights
        // ...

    }
}

void EXTI2_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line2) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line2);

        // Control the third group of running lights
        // ...

    }
}

void EXTI3_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line3) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line3);

        // Control the fourth group of running lights
        // ...

    }
}

以上代码中的四个中断处理函数分别对应四个外部中断，每个函数中都需要根据按键的触发来控制对应的跑马灯。

3. 跑马灯控制：

在中断处理函数中，需要编写代码来控制跑马灯的运行，以下是一个简单的跑马灯控制代码：

void run_light(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
{
    GPIO_SetBits(GPIOx, GPIO_Pin);
    delay_ms(100);
    GPIO_ResetBits(GPIOx, GPIO_Pin);
}

该函数可以让一个LED灯亮100ms后熄灭。

完整代码如下：

#include "stm32f10x.h"

void EXTI_Config(void);
void run_light(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin);

int main(void)
{
    EXTI_Config();

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    while (1)
    {

    }
}

void EXTI_Config(void)
{
    EXTI_InitTypeDef EXTI_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;

    /* Enable GPIOA clock */
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);

    /* Configure PA0, PA1, PA2 and PA3 as input with pull-up */
    GPIO_InitTypeDef GPIO_InitStructure;
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);

    /* Connect EXTI0-3 Line to PA0-3 pin */
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource0);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource1);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource2);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource3);

    /* Configure EXTI0-3 */
    EXTI_InitStructure.EXTI_Line = EXTI_Line0 | EXTI_Line1 | EXTI_Line2 | EXTI_Line3;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);

    /* Enable and set EXTI0-3 Interrupt to the highest priority */
    NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x02;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x03;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

void run_light(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
{
    GPIO_SetBits(GPIOx, GPIO_Pin);
    delay_ms(100);
    GPIO_ResetBits(GPIOx, GPIO_Pin);
}

void EXTI0_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line0) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line0);

        // Control the first group of running lights
        run_light(GPIOB, GPIO_Pin_0);
        run_light(GPIOB, GPIO_Pin_1);
        run_light(GPIOB, GPIO_Pin_2);
        run_light(GPIOB, GPIO_Pin_3);

    }
}

void EXTI1_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line1) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line1);

        // Control the second group of running lights
        run_light(GPIOB, GPIO_Pin_0);
        run_light(GPIOB, GPIO_Pin_1);

    }
}

void EXTI2_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line2) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line2);

        // Control the third group of running lights
        run_light(GPIOB, GPIO_Pin_2);
        run_light(GPIOB, GPIO_Pin_3);

    }
}

void EXTI3_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line3) != RESET)
    {
        EXTI_ClearITPendingBit(EXTI_Line3);

        // Control the fourth group of running lights
        run_light(GPIOB, GPIO_Pin_0);
        run_light(GPIOB, GPIO_Pin_3);

    }
}