定时器和GPIO中断

Sunwaz · 发表于 2016-6-18 17:02:07

在使用超声波传感器的时候，发现一个问题，超声波模块能用，示波器所显示的高电平时间长度和测试距离能够对应的上，最后使用的时候用定时器来对数据进行计时则发现所计数的时间不对。具体代码如下以下是GPIO的初始化
[mw_shl_code=c,true]static void HLSer_GPIO_Config(void)
{
GPIO_InitTypeDef InitStructure;
RCC_AHB1PeriphClockCmd(HLSer_Trig_GPIO_Clk | HLSer_Echo_GPIO_Clk,ENABLE);
InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;
InitStructure.GPIO_OType = GPIO_OType_PP;
InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

InitStructure.GPIO_Mode  = GPIO_Mode_OUT;
InitStructure.GPIO_Pin = HLSer_Trig_GPIO_Pin;
GPIO_Init(HLSer_Trig_GPIO_Port,&InitStructure);
InitStructure.GPIO_Pin = HLSer_Echo_GPIO_Pin;
InitStructure.GPIO_Mode  = GPIO_Mode_IN;
InitStructure.GPIO_PuPd  = GPIO_PuPd_UP;
GPIO_Init(HLSer_Echo_GPIO_Port,&InitStructure);
}[/mw_shl_code]

Sunwaz · 发表于 2016-6-18 17:02:08

问题解决。。在跳出while的时候关闭定时器，清零定时器，但是中间会多出500us的多余时间，将这个多余时间减掉就好了。。。不用再中断里面关闭定时器。关闭不了。

Sunwaz · 发表于 2016-6-18 17:03:59

以下是中断的初始化
[mw_shl_code=applescript,true] static void ULSer_EXTI_Config(void)
{
   EXTI_InitTypeDef EXTI_InitStructure;
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG,ENABLE);
   SYSCFG_EXTILineConfig(HLSer_EXTI_PortSource,
                        HLSer_EXTI_PinSource);
   EXTI_InitStructure.EXTI_Line    = HLSer_EXTI_Line;
   EXTI_InitStructure.EXTI_LineCmd = ENABLE;
   EXTI_InitStructure.EXTI_Mode    = EXTI_Mode_Interrupt;
   EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
   EXTI_Init(&EXTI_InitStructure);
}[/mw_shl_code]
[mw_shl_code=c,true]static void HLSer_NVIC_Config(void)
{
   NVIC_InitTypeDef NVIC_InitStructure;
   NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
   NVIC_InitStructure.NVIC_IRQChannel                = HLSer_EXTI_IRQ;
   NVIC_InitStructure.NVIC_IRQChannelCmd             = ENABLE;
   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
   NVIC_InitStructure.NVIC_IRQChannelSubPriority       = 2;
   NVIC_Init(&NVIC_InitStructure);
}[/mw_shl_code]

Sunwaz · 发表于 2016-6-18 17:05:52

定时器初始化
[mw_shl_code=c,true]static void TIM6_Config(void)
{
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  RCC_APB1PeriphClockCmd(TIM6_CLK, ENABLE);
  TIM_TimeBaseStructure.TIM_Period = 4999-1;
  TIM_TimeBaseStructure.TIM_Prescaler = 180-1;
TIM_TimeBaseInit(TIM6_Port, &TIM_TimeBaseStructure);
//TIM_ClearFlag(TIM6_Port, TIM_FLAG_Update);
//TIM_ITConfig(TIM6_Port,TIM_IT_Update,ENABLE);
//TIM_Cmd(TIM6_Port, ENABLE);
}[/mw_shl_code]

Sunwaz · 发表于 2016-6-18 17:07:04

中断函数
[mw_shl_code=c,true]void HLSer_EXTI_IRQHandler(void)
{
if(EXTI_GetITStatus(HLSer_EXTI_Line) != RESET)
{
TIM_Cmd(TIM6,DISABLE);
HLSer_User.Count = TIM_GetCounter(TIM6);
TIM_SetCounter(TIM6,0);
Interrupt_Flag.HLSer_Flag = SET;
//TIM_Cmd(TIM6,ENABLE);
}
EXTI_ClearITPendingBit(HLSer_EXTI_Line);
}[/mw_shl_code]

Sunwaz · 发表于 2016-6-18 17:07:55

[mw_shl_code=c,true]float HLSer_GetValue(void)
{
HLSer_Trig_Out = 1;
Delay_us(20);
HLSer_Trig_Out = 0;
//ULSer_EXTI_Cmd(ENABLE);
while(HLSer_Echo_In != SET);
TIM_SetCounter(TIM6,0);
TIM_Cmd(TIM6,ENABLE);
while(Interrupt_Flag.HLSer_Flag != SET);
Interrupt_Flag.HLSer_Flag = RESET;
HLSer_User.length = (HLSer_User.Count) *3.4/ 100;
//ULSer_EXTI_Cmd(DISABLE);
return HLSer_User.length;
}[/mw_shl_code]