PB15作为超声波的发射端，一直出现问题

风之次仞 · 发表于 2016-9-26 11:08:19

void ultra_init()
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB|RCC_APB2Periph_GPIOC|RCC_APB2Periph_GPIOA, ENABLE);

GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6|GPIO_Pin_7|GPIO_Pin_8|GPIO_Pin_9; //PE2接受回波，echo1
GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_IN_FLOATING;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOC, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_15; //PB15触发，trig2
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_11; //PA11触发，trig1
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_ResetBits(GPIOB,GPIO_Pin_15);
GPIO_ResetBits(GPIOC,GPIO_Pin_12);
TIM_DeInit(TIM5);

TIM_TimeBaseStructure.TIM_Period=20000;//超时时间0.02s，最远可测距离3.4m
TIM_TimeBaseStructure.TIM_Prescaler=72-1;//5us,+1
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up; //??????
TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure);
TIM_ITConfig(TIM5,TIM_IT_Update,ENABLE);

NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn;  //TIM3??
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3;  //?????0?
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;  //????3?
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ?????
NVIC_Init(&NVIC_InitStructure);  //???NVIC???
TIM_Cmd(TIM5, DISABLE);
}
void TIM5_IRQHandler()
{
if(TIM_GetITStatus(TIM5,TIM_IT_Update) == SET)
{
TIM_ClearITPendingBit(TIM5,TIM_FLAG_Update);
overflow++;
}
}

问题描述:程序采集4路超声波信息，PA11是其中2路的发射端，PB15是另外2路的发射端，利用TIM5作超时处理，PA11和PB15的设置一模一样，但是PA11的2路超声波好使，而PB15的2路一直有问题。PS.程序中还有TIM4作PWM输出，不知道互相影响吗？求高手帮忙看一下