2025年第16届蓝桥杯嵌入式竞赛学习笔记（六）：使用定时器实现按键的长按短按

本文链接：https://blog.youkuaiyun.com/qq_62350698/article/details/144964982

1.新建工程

使用第五章定时器中断的STM32CubeMX和Keil5

2.图形化配置

在STM32CubeMX界面选择TIM3时钟，Clock Source选择Internal Clock (内部时钟)

PSC填写8000-1，ARR填写65535

3.代码部分

主函数中初始化定时器TIM3：HAL_TIM_Base_Start(&htim3);

int main(void)
{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_TIM2_Init();
  MX_TIM3_Init();
  /* USER CODE BEGIN 2 */
	HAL_GPIO_WritePin(GPIOD,GPIO_PIN_2,GPIO_PIN_RESET);
	LCD_Init();
	LCD_Clear(Black);
	LCD_SetBackColor(Black);
	LCD_SetTextColor(White);
	
	HAL_TIM_Base_Start_IT(&htim2);
	HAL_TIM_Base_Start(&htim3);
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
		lcd_show();
		Key_Scan();
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

修改Key_Scan函数，给Last_State置1防止刚进来就通过短按if

#include "headfile.h"

uint8_t B1_State;
uint8_t B1_Last_State = 1;
uint8_t B2_State;
uint8_t B2_Last_State = 1;
uint8_t B3_State;
uint8_t B3_Last_State = 1;
uint8_t B4_State;
uint8_t B4_Last_State = 1;

extern int count;

void Key_Scan(void)
{
	B1_State = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_0);
	B2_State = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_1);
	B3_State = HAL_GPIO_ReadPin(GPIOB,GPIO_PIN_2);
	B4_State = HAL_GPIO_ReadPin(GPIOA,GPIO_PIN_0);
	
	if(B1_State == 0 && B1_Last_State == 1)
	{
		TIM3 -> CNT = 0;
	}
	else if(B1_State == 0 && B1_Last_State == 0)
	{
		if(TIM3 -> CNT >= 10000)
			count++;
	}
	else if(B1_State == 1 && B1_Last_State == 0)
	{
		if(TIM3 -> CNT < 10000)
			count++;
	}
	
	if(B2_State == 0 && B2_Last_State == 1)
	{
		TIM3 -> CNT = 0;
	}
	else if(B2_State == 0 && B2_Last_State == 0)
	{
		if(TIM3 -> CNT >= 10000)
			count--;
	}
	else if(B2_State == 1 && B2_Last_State == 0)
	{
		if(TIM3 -> CNT < 10000)
			count--;
	}
	
	if(B3_State == 0 && B3_Last_State == 1)
	{
		count++;
	}
	
	if(B4_State == 0 && B4_Last_State == 1)
	{
		count--;
	}
	
	B1_Last_State = B1_State;
	B2_Last_State = B2_State;
	B3_Last_State = B3_State;
	B4_Last_State = B4_State;
}