按键判断（单击、长按）

key.h

#ifndef _KEY_H_
#define _KEY_H_

#include "main.h"
#include "stdbool.h"	

struct keys				
{
	uint8_t stg;
        uint16_t time;		
	bool flag;			
	bool keycode;
        bool flag_long;		
};

#endif

key.c

#include "key.h"

struct keys key[4];		

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)		
{
	if(htim ->Instance == TIM3)									
	{															
		key[0].keycode = HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0);	
		key[1].keycode = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_0);
		key[2].keycode = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_1);
		key[3].keycode = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_2);
		
		for(uint8_t i = 0; i < 4; i++)							
		{
			switch(key[i].stg)									
			{
				case 0:
				{
					if(key[i].keycode == 0)						
						key[i].stg = 1;							
				}
				break;
				case 1:
				{
					if(key[i].keycode == 0)						
					{
						key[i].stg = 2;													
					}
					else										
					{
						key[i].stg = 0;							
					}
				}
				break;
				case 2:
				{	
					if(key[i].keycode == 1)
					{
						key[i].stg = 0;
						if(key[i].time < 100)
						{
							key[i].flag = 1;
						}							
					}						
					else
					{
						key[i].time++;
						if(key[i].time >= 100)
						{
							key[i].flag_long = 1;
						}
					}
				}
				break;
			}
		}
	}
}

HAL_TIM_Base_Start_IT(&htim3); //开启定时器