蓝桥杯嵌入式G4-按键（单击双击长按）定时器扫描_蓝桥杯嵌入式长按按键

按键原理图

CubeMX配置

GPIO端口配置

定时器配置（TIM3 10ms）

计算方法80M/（period+1）*(counter+1)得到定时频率，倒数为定时时长。

普通按键

新建一个interrupt.c和interrupt.h的文件

interrut.h

#ifndef _INTERRUPT_H_
#define _INTERRUPT_H_
 
#include"main.h"
#include"stdbool.h"//引用头文件使用bool类型节约空间
struct keys
{
    uchar judge_sta;
    bool key_sta;
    bool key_flag;
};
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim);
 
#endif

interrupt.c

#include"interrupt.h"
struct keys key[4]={0,0,0};
 
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    if(htim->Instance==TIM3)
    {
        key[0].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_0);
        key[1].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_1);
        key[2].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_2);
        key[3].key_sta=HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0);
    
        for(uchar i=0;i<4;i++)
        {
            switch(key[i].judge_sta)
            {
                case 0:
                {
                    if(key[i].key_sta==0) key[i].judge_sta=1;
                }
                break;
                case 1:
                {
                    if(key[i].key_sta==0)
                    {
                        key[i].judge_sta=2;
                        key[i].key_flag=1;     //0->1 按键消抖
                    }
                    else
                        key[i].judge_sta=0;
                }
                break;
                case 2:
                {
                    if(key[i].key_sta==1)
                    {
                        key[i].judge_sta=0;  //判断松手过程
                    }
                }
                break;
            }
        }
    }
}

按键处理函数

void key_scan()
{
    if(key[0].key_flag==1)
    {
        char text[30];
        sprintf(text,"    KEY0down    ");
        LCD_DisplayStringLine(Line4,(uint8_t *)text);
        led_disp(0x81);
        key[0].key_flag=0;
    }
    if(key[1].key_flag==1)
    {
        char text[30];
        sprintf(text,"    KEY1down    ");
        LCD_DisplayStringLine(Line4,(uint8_t *)text);
        led_disp(0x42);
        key[1].key_flag=0;
    }
    if(key[2].key_flag==1)
    {
        char text[30];
        sprintf(text,"    KEY2down    ");
        LCD_DisplayStringLine(Line4,(uint8_t *)text);
        led_disp(0x24);
        key[2].key_flag=0;
    }
    if(key[3].key_flag==1)
    {
        char text[30];
        sprintf(text,"    KEY3down    ");
        LCD_DisplayStringLine(Line4,(uint8_t *)text);
        led_disp(0x18);
        key[3].key_flag=0;
    }
}

主函数头文件引用

#include"led.h"
#include"lcd.h"
#include"stdio.h"
#include"interrupt.h"
 
extern struct keys key[4];//声明外部变量，在主函数中使用

主函数调用上面的按键处理函数即可。

while（1）前面记得开启定时器3的中断HAL_TIM_Base_Start_IT(&htim3);//开启中断

长按

interrupt.h

#ifndef _INTERRUPT_H_
#define _INTERRUPT_H_
 
#include"main.h"
#include"stdbool.h"
struct keys
{
    uchar judge_sta;
    bool key_sta;
    bool short_flag;
    uint key_count;
    bool long_flag;
    
};
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim);
 
#endif

interrupt.c

#include"interrupt.h"
struct keys key[4]={0,0,0};
 
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    if(htim->Instance==TIM3)
    {
        key[0].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_0);
        key[1].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_1);
        key[2].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_2);
        key[3].key_sta=HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0);
    
        for(uchar i=0;i<4;i++)
        {
            switch(key[i].judge_sta)
            {
                case 0:
                {
                    if(key[i].key_sta==0)
                    {
                         key[i].judge_sta=1;
                        key[i].key_count=0;
                    }
                }
                break;
                case 1:
                {
                    if(key[i].key_sta==0)
                    {
                        key[i].judge_sta=2;
                    }
                    else
                        key[i].judge_sta=0;
                }
                break;
                case 2:
                {
                    if(key[i].key_sta==1)
                    {
                        key[i].judge_sta=0;  //判断松手过程
                        if(key[i].key_count<70) key[i].short_flag=1;
                    }
                    else 
                    {    
                        key[i].key_count++;
                        if(key[i].key_count>=70) key[i].long_flag=1;
                    }
                }
                break;
            }
        }
    }
}

双击

interrupt.h

#ifndef _INTERRUPT_H_
#define _INTERRUPT_H_
 
#include"main.h"
#include"stdbool.h"
struct keys
{
    uchar judge_sta;
    bool key_sta;
    bool short_flag;
    uint key_count;
    bool long_flag;
    bool double_timerEN;
    uchar double_timer;
    bool double_flag;
};
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim);
 
#endif

interrupt.c

#include"interrupt.h"
struct keys key[4]={0};
 
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    if(htim->Instance==TIM3)
    {
        key[0].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_0);
        key[1].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_1);
        key[2].key_sta=HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_2);
        key[3].key_sta=HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0);
    
        for(uchar i=0;i<4;i++)
        {
            switch(key[i].judge_sta)
            {
                case 0:
                {
                    if(key[i].key_sta==0)
                    {
                         key[i].judge_sta=1;
                        key[i].key_count=0;
                    }
                }
                break;
                case 1:
                {
                    if(key[i].key_sta==0)
                    {
                        key[i].judge_sta=2;
                    }
                    else
                        key[i].judge_sta=0;
                }
                break;
                case 2:
                {
                    if(key[i].key_sta==1&&key[i].key_count<70)
                    {
                        if(key[i].double_timerEN==0)
                        {
                            key[i].double_timerEN=1;
                            key[i].double_timer=0;
                        }
                        else
                        {
                            key[i].double_flag=1;
                            key[i].double_timerEN=0;
                        }
                        key[i].judge_sta=0;
                    }
                    else if(key[i].key_sta==1&&key[i].key_count>=70) key[i].judge_sta=0;
                    else
                    {
                        key[i].key_count++;
                        if(key[i].key_count>=70) key[i].long_flag=1;
                    }
                }
                break;
            }
            
            if(key[i].double_timerEN==1)
            {
                key[i].double_timer++;
                if(key[i].double_timer>35)
                {
                    key[i].short_flag=1;
                    key[i].double_timerEN=0;
                }
            }
        }
    }
}

双击代码需要理解其中的逻辑就比较简单。