if(EXTI_GetITStatus(KEY2_INT_EXTI_LINE) != RESET) { if(count2<5) { p=p/2; time=time/2; count2++; } if(count2>=5 && count2<10) { p=p*2; time=time*2; count2++; } if(count2>=10) { count2=0; } //清除中断标志位 EXTI_ClearITPendingBit(KEY2_INT_EXTI_LINE); }

这段代码看起来像是 STM32F系列单片机上的外部中断处理函数，当KEY2按键被按下时，会执行相应的处理操作。其中，count2变量的值在5次以内会除以2，同时time也会除以2；在5~10次之间，count2变量的值会乘以2，同时time也会乘以2；当count2大于等于10时，count2会被重置为0。最后，该中断标志位会被清除。

相关问题

写一个stm32单片机的程序：使用4个LED，3个按键，按键1控制正向流水灯，按键2控制反向流水灯，按键3控制流水灯的数量（1个，2个，3个））

本题答案为参考答案，仅供参考。

#include "stm32f10x.h"

#define LED1_PIN        GPIO_Pin_0
#define LED2_PIN        GPIO_Pin_1
#define LED3_PIN        GPIO_Pin_2
#define LED4_PIN        GPIO_Pin_3

#define KEY1_PIN        GPIO_Pin_4
#define KEY2_PIN        GPIO_Pin_5
#define KEY3_PIN        GPIO_Pin_6

int main(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    EXTI_InitTypeDef EXTI_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
    
    // 使能GPIOA和AFIO时钟
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE);
    // 使能EXTI0和EXTI1中断
    NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn | EXTI1_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x00;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
    
    // 配置LED引脚为推挽输出
    GPIO_InitStructure.GPIO_Pin = LED1_PIN | LED2_PIN | LED3_PIN | LED4_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    
    // 配置KEY1引脚为上拉输入，并使能其中断
    GPIO_InitStructure.GPIO_Pin = KEY1_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource4);
    EXTI_InitStructure.EXTI_Line = EXTI_Line4;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);
    
    // 配置KEY2引脚为上拉输入，并使能其中断
    GPIO_InitStructure.GPIO_Pin = KEY2_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource5);
    EXTI_InitStructure.EXTI_Line = EXTI_Line5;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);
    
    // 配置KEY3引脚为上拉输入，并使能其中断
    GPIO_InitStructure.GPIO_Pin = KEY3_PIN;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource6);
    EXTI_InitStructure.EXTI_Line = EXTI_Line6;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);
    
    // 初始化流水灯数量为1
    uint8_t count = 1;
    
    while (1)
    {
        // 根据流水灯数量控制LED输出
        switch (count)
        {
        case 1:
            GPIO_SetBits(GPIOA, LED1_PIN);
            GPIO_ResetBits(GPIOA, LED2_PIN | LED3_PIN | LED4_PIN);
            break;
        case 2:
            GPIO_SetBits(GPIOA, LED1_PIN | LED2_PIN);
            GPIO_ResetBits(GPIOA, LED3_PIN | LED4_PIN);
            break;
        case 3:
            GPIO_SetBits(GPIOA, LED1_PIN | LED2_PIN | LED3_PIN);
            GPIO_ResetBits(GPIOA, LED4_PIN);
            break;
        default:
            GPIO_SetBits(GPIOA, LED1_PIN | LED2_PIN | LED3_PIN | LED4_PIN);
            break;
        }
    }
}

void EXTI0_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line0) != RESET)
    {
        // 控制正向流水灯
        EXTI_ClearITPendingBit(EXTI_Line0);
    }
}

void EXTI1_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line1) != RESET)
    {
        // 控制反向流水灯
        EXTI_ClearITPendingBit(EXTI_Line1);
    }
}

void EXTI9_5_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line5) != RESET)
    {
        // 控制流水灯数量
        EXTI_ClearITPendingBit(EXTI_Line5);
    }
}

stm32f4单片机设计电子密码锁的代码

好的，以下是基于STM32F4单片机设计电子密码锁的代码，仅供参考：

#include "stm32f4xx.h"
#include "stm32f4xx_gpio.h"
#include "stm32f4xx_rcc.h"
#include "stm32f4xx_tim.h"
#include "stm32f4xx_exti.h"
#include "stm32f4xx_syscfg.h"
#include "misc.h"

#define PASSWORD_SIZE 4 //密码长度
#define PASSWORD "1234"  //密码
#define LOCK_TIME 30     //锁定时间

int key_count = 0; //按键次数
int lock_count = 0; //锁定计数器
int lock_flag = 0; //锁定标志位

void GPIO_Configuration(void);
void TIM_Configuration(void);
void EXTI_Configuration(void);
void NVIC_Configuration(void);
void Delay(__IO uint32_t nCount);

int main(void)
{
    GPIO_Configuration();
    TIM_Configuration();
    EXTI_Configuration();
    NVIC_Configuration();

    while (1)
    {
        if (lock_flag == 0)
        {
            if (key_count == PASSWORD_SIZE)
            {
                if (strcmp(PASSWORD, input_password) == 0)
                {
                    //密码正确
                    GPIO_SetBits(GPIOG, GPIO_Pin_13);
                    Delay(5000000);
                    GPIO_ResetBits(GPIOG, GPIO_Pin_13);
                    key_count = 0;
                }
                else
                {
                    //密码错误
                    key_count = 0;
                    lock_flag = 1;
                }
            }
        }
        else
        {
            //锁定状态
            GPIO_SetBits(GPIOG, GPIO_Pin_14);
            Delay(5000000);
            GPIO_ResetBits(GPIOG, GPIO_Pin_14);
            lock_count++;
            if (lock_count >= LOCK_TIME)
            {
                lock_count = 0;
                lock_flag = 0;
            }
        }
    }
}

void GPIO_Configuration(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;

    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOG, ENABLE);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_14;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOG, &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;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
    GPIO_Init(GPIOE, &GPIO_InitStructure);

    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
    GPIO_Init(GPIOE, &GPIO_InitStructure);
}

void TIM_Configuration(void)
{
    TIM_TimeBaseInitTypeDef TIM_InitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);

    TIM_InitStructure.TIM_Period = 49;
    TIM_InitStructure.TIM_Prescaler = 8399;
    TIM_InitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    TIM_InitStructure.TIM_CounterMode = TIM_CounterMode_Up;
    TIM_TimeBaseInit(TIM2, &TIM_InitStructure);
    TIM_ITConfig(TIM2, TIM_IT_Update, ENABLE);
    TIM_Cmd(TIM2, ENABLE);
}

void EXTI_Configuration(void)
{
    EXTI_InitTypeDef EXTI_InitStructure;

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

    SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource4);
    SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource5);
    SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource6);
    SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOE, EXTI_PinSource7);

    EXTI_InitStructure.EXTI_Line = EXTI_Line4 | EXTI_Line5 | EXTI_Line6 | EXTI_Line7;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);
}

void NVIC_Configuration(void)
{
    NVIC_InitTypeDef NVIC_InitStructure;

    NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

void Delay(__IO uint32_t nCount)
{
    while (nCount--)
    {
    }
}

void EXTI4_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line4) != RESET)
    {
        Delay(10000);
        if (GPIO_ReadInputDataBit(GPIOE, GPIO_Pin_4) == SET)
        {
            //按键按下
            input_password[key_count++] = '1';
        }
        EXTI_ClearITPendingBit(EXTI_Line4);
    }
}

void EXTI9_5_IRQHandler(void)
{
    if (EXTI_GetITStatus(EXTI_Line5) != RESET)
    {
        Delay(10000);
        if (GPIO_ReadInputDataBit(GPIOE, GPIO_Pin_5) == SET)
        {
            //按键按下
            input_password[key_count++] = '2';
        }
        EXTI_ClearITPendingBit(EXTI_Line5);
    }
    else if (EXTI_GetITStatus(EXTI_Line6) != RESET)
    {
        Delay(10000);
        if (GPIO_ReadInputDataBit(GPIOE, GPIO_Pin_6) == SET)
        {
            //按键按下
            input_password[key_count++] = '3';
        }
        EXTI_ClearITPendingBit(EXTI_Line6);
    }
    else if (EXTI_GetITStatus(EXTI_Line7) != RESET)
    {
        Delay(10000);
        if (GPIO_ReadInputDataBit(GPIOE, GPIO_Pin_7) == SET)
        {
            //按键按下
            input_password[key_count++] = '4';
        }
        EXTI_ClearITPendingBit(EXTI_Line7);
    }
}

void TIM2_IRQHandler(void)
{
    if (TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET)
    {
        lock_count++;
        if (lock_count >= LOCK_TIME)
        {
            lock_count = 0;
            lock_flag = 0;
        }
        TIM_ClearITPendingBit(TIM2, TIM_IT_Update);
    }
}

这份代码主要实现了基于STM32F4单片机的电子密码锁，通过按键输入密码，判断密码是否正确，如果密码正确则亮起绿色LED灯，如果密码错误则亮起红色LED灯并锁定系统一段时间。