STM32一枚按键的旅行

看硬件原理图

GPIO的C13和E0是两个按键，平时是高电平，当按键下去的时候就接地变成低电平。

开始软件配置：

宏定义两个按键

(仔细看是有必要的因为你看 GPIO_Pin_13和GPIO_PinSource13的排序是不同的)

#define TSKEY1GPIO          GPIOC
#define TSKEY1GPIOPIN        GPIO_Pin_13
#define TSKEY1IRQ         EXTI15_10_IRQn
#define TSKEY1_ExtiPortsource  GPIO_PortSourceGPIOC
#define TSKEY1_ExtiPin     GPIO_PinSource13
#define TSKEY1_Line  EXTI_Line13




#define TSKEY2GPIO          GPIOE
#define TSKEY2GPIOPIN        GPIO_Pin_0
#define TSKEY2IRQ                EXTI0_IRQn
#define TSKEY2_ExtiPortsource  GPIO_PortSourceGPIOE
#define TSKEY2_ExtiPin     GPIO_PinSource0
#define TSKEY2_Line  EXTI_Line0

初始化函数：

void TS_Key_init(void)
{


    GPIO_InitTypeDef GPIO_InitStructure;
    NVIC_InitTypeDef NVIC_InitStructure;
    EXTI_InitTypeDef EXTI_InitStructure;
  
    RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOC|RCC_APB2Periph_GPIOE| RCC_APB2Periph_AFIO,ENABLE ) ;
  //RCC_APB2Periph_AFIO不能没有！！



    GPIO_InitStructure.GPIO_Pin = TSKEY1GPIOPIN ;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//MUST 如果是GPIO_Mode_IN_FLOATING则失败;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_Init(TSKEY1GPIO, &GPIO_InitStructure);


    NVIC_InitStructure.NVIC_IRQChannel = TSKEY1IRQ;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);


    GPIO_EXTILineConfig(TSKEY1_ExtiPortsource, TSKEY1_ExtiPin);
    EXTI_InitStructure.EXTI_Line = TSKEY1_Line;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling ;  
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);


    GPIO_InitStructure.GPIO_Pin = TSKEY2GPIOPIN ;
    GPIO_Init(TSKEY2GPIO, &GPIO_InitStructure);

    NVIC_InitStructure.NVIC_IRQChannel = TSKEY2IRQ;
   NVIC_Init(&NVIC_InitStructure);

    GPIO_EXTILineConfig(TSKEY2_ExtiPortsource, TSKEY2_ExtiPin);
    EXTI_InitStructure.EXTI_Line = TSKEY2_Line;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling ;  
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);

}

现在就可以用中断了，到it.c去写服务程序吧。

int it=100;

u8 EXit_Delay(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)//消抖 延时以后去读 如果还是低电平 那就是中断！
{
    OSTimeDlyHMSM(0, 0, 0, 100);
    if(GPIO_ReadInputDataBit(GPIOx,GPIO_Pin)==RESET)
        return 1;
    else 
        return 0;
}
这里主要是因为init的时候是下降沿是中断，所以去读，如果是0那就真的是中断。




void EXTI0_IRQHandler(void)
{
       OS_CPU_SR  cpu_sr;
OS_ENTER_CRITICAL();
OSIntNesting++;
OS_EXIT_CRITICAL();


if(EXTI_GetITStatus(TSKEY2_Line) != RESET)
{
      
       if( EXit_Delay(TSKEY2GPIO,TSKEY2GPIOPIN))
       {
it+=10;
       }

EXTI_ClearITPendingBit(TSKEY2_Line);
}
OSIntExit();


}

void EXTI15_10_IRQHandler(void)
{
    OS_CPU_SR  cpu_sr;

    OS_ENTER_CRITICAL();
    OSIntNesting++;
    OS_EXIT_CRITICAL();


    if(EXTI_GetITStatus(TSKEY1_Line) != RESET)            
    {
if( EXit_Delay(TSKEY1GPIO,TSKEY1GPIOPIN))
       {
it-=5;
      }
      EXTI_ClearITPendingBit(TSKEY1_Line);
    }
    
    OSIntExit();

}

思考：

1对比文章

https://blog.csdn.net/tianshi_1988/article/details/52175434

为什么 GPIO_Mode_IPU成功  GPIO_Mode_IN_FLOATING失败;

2复用不能丢

3消抖是软件写的，如果你是上升沿触发的话，那就是延时一会读，是1

回答：

http://www.stmcu.org/module/forum/thread-616140-1-1.html