[嵌入式]STM32矩阵按键（定时器）

? ? ? ? 由于采用延时函数会影响程序速度，所以采用定时器中断写的矩阵扫描按键。利用简单的状态机思想。

1.定时器初始化

//定时器初始化
void TIM2_Configuration(void)
{
    TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
    NVIC_InitTypeDef NVIC_InitStructure; 
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 , ENABLE);
    TIM_DeInit(TIM2);
    TIM_TimeBaseStructure.TIM_Period=1000-1;	//自动重装载寄存器周期的值(计数值) 
    /* 累计 TIM_Period个频率后产生一个更新或者中断 */
    TIM_TimeBaseStructure.TIM_Prescaler= (72 - 1);	//时钟预分频数 72M/72      
    TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //向上计数模式 
    TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
    TIM_ClearFlag(TIM2, TIM_FLAG_Update);	// 清除溢出中断标志 
    TIM_ITConfig(TIM2,TIM_IT_Update,ENABLE);
    TIM_Cmd(TIM2, ENABLE);	 
	
		
    NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;	
		NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);	  
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;	
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);
}

//设置20ms定时器中断
void TIM2_IRQHandler(void)
{
	if ( TIM_GetITStatus(TIM2 , TIM_IT_Update) != RESET ) 
	{
        
        if(count_aj<20 )
        {
            count_aj++;
        }
        else
        {
            count_aj = 0;
            flag_aj = 1;
        }

    

	}	
		TIM_ClearITPendingBit(TIM2 , TIM_FLAG_Update); 
}

2.按键初始化

// 按键初始化
void Key_init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

    /********4行输出*********/
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;  // 推挽输出
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    /********4列输入*********/
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 ;//| GPIO_Pin_15;  //  可换4x4  
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;    //  上拉输入
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
}

3.key.c

void Key_Scan(void)
{

//                            第一行按键检查                            //
  

        if(flag_aj)  //设计定时器的循环时间，在时间内循环扫描
    {
        Hang_00_L;//把第一行输出低电平
        Hang_01_H;
        Hang_02_H;
        Hang_03_H;

        if(Lie_00_V == 0)
        {
            key0_up=0;
        }
        else
        {
            key0_up = 1 ;
        }

        if(Lie_01_V == 0)
        {
            key1_up=0;
        }
        else
        {
            key1_up = 1 ;
        }

        if(Lie_02_V == 0)
        {
            key2_up=0;
        }
        else
        {
            key2_up = 1 ;
        }
    
    if ((key0_dw == 1)&&(key0_up == 0))
    {
        key1_on = 1;
    }
    if ((key1_dw == 1)&&(key1_up == 0))
    {
        key2_on = 1;
    }
    if ((key2_dw == 1)&&(key2_up == 0))
    {
        key3_on = 1;
    }

    if(key1_on ==1)
    {
       key1_mima = 0x01;
        key1_on=0;
    }
    if(key2_on ==1)
    {
        key2_mima = 0x02;
        key2_on=0;
    }
    if(key3_on ==1)
    {
        key3_mima = 0x03; 
        key3_on=0;
    }

    key0_dw = key0_up;
    key1_dw = key1_up;
    key2_dw = key2_up;


//                            第二行按键检查                            //
        
        
        
        
        Hang_00_H;
        Hang_01_L;//把第二行输出低电平
        Hang_02_H;
        Hang_03_H;

        if(Lie_00_V == 0)
        {
            key3_up=0;
        }
        else
        {
            key3_up = 1 ;
        }

        if(Lie_01_V == 0)
        {
            key4_up=0;
        }
        else
        {
            key4_up = 1 ;
        }

        if(Lie_02_V == 0)
        {
            key5_up=0;
        }
        else
        {
            key5_up = 1 ;
        }
    
    if ((key3_dw == 1)&&(key3_up == 0))
    {
        key4_on = 1;

    }
    if ((key4_dw == 1)&&(key4_up == 0))
    {
        key5_on = 1;
    }
    if ((key5_dw == 1)&&(key5_up == 0))
    {
        key6_on = 1;
    }

    if(key4_on ==1)
    {
       key4_mima = 0x04;
        key4_on=0;
    }
    if(key5_on ==1)
    {
        USART1_Send_Byte(5);
        key5_on=0;
    }
    if(key6_on ==1)
    {
        USART1_Send_Byte(6);
        key6_on=0;
    }

    key3_dw = key3_up;
    key4_dw = key4_up;
    key5_dw = key5_up;

//                            第三行按键检查                            //      
        
        Hang_00_H;
        Hang_01_H;
        Hang_02_L;//把第三行输出低电平
        Hang_03_H;

        if(Lie_00_V == 0)
        {
            key6_up=0;
        }
        else
        {
            key6_up = 1 ;
        }

        if(Lie_01_V == 0)
        {
            key7_up=0;
        }
        else
        {
            key7_up = 1 ;
        }

        if(Lie_02_V == 0)
        {
            key8_up=0;
        }
        else
        {
            key8_up = 1 ;
        }
    
    if ((key6_dw == 1)&&(key6_up == 0))
    {
        key7_on = 1;

    }
    if ((key7_dw == 1)&&(key7_up == 0))
    {
        key8_on = 1;
    }
    if ((key8_dw == 1)&&(key8_up == 0))
    {
        key9_on = 1;
    }

    if(key7_on ==1)
    {
        USART1_Send_Byte(7);
        key7_on=0;
    }
    if(key8_on ==1)
    {
        USART1_Send_Byte(8);
        key8_on=0;
    }
    if(key9_on ==1)
    {
        USART1_Send_Byte(9);
        key9_on=0;
    }

    key6_dw = key6_up;
    key7_dw = key7_up;
    key8_dw = key8_up;

        //                            第四行按键检查                            //      
        
                Hang_00_H;
        Hang_01_H;
        Hang_02_H;
        Hang_03_L;//把第四行输出低电平

        if(Lie_00_V == 0)
        {
            key9_up=0;
        }
        else
        {
            key9_up = 1 ;
        }

        if(Lie_01_V == 0)
        {
            keyA_up=0;
        }
        else
        {
            keyA_up = 1 ;
        }

        if(Lie_02_V == 0)
        {
            keyB_up=0;
        }
        else
        {
            keyB_up = 1 ;
        }
    
    if ((key9_dw == 1)&&(key9_up == 0))
    {
        key10_on = 1;

    }
    if ((keyA_dw == 1)&&(keyA_up == 0))
    {
        key0_on = 1;
    }
    if ((keyB_dw == 1)&&(keyB_up == 0))
    {
        key11_on = 1;
    }

    if(key10_on ==1)
    {
       USART1_Send_Byte(10);
        key10_on=0;
    }
    if(key0_on ==1)
    {
       USART1_Send_Byte(0);
        key0_on=0;
    }
    if(key11_on ==1)
    {
       USART1_Send_Byte(11);
        key11_on=0;
    }

    key9_dw = key9_up;
    keyA_dw = keyA_up;
    keyB_dw = keyB_up;

       flag_aj=0; 

    }







}