新手求助：关于使用GPIO发送高低点平信号

pipisi · 发表于 2016-11-13 17:39:00

大家好，第一次接触单片机，目前使用的是STM32F407，现在想使用PE5发送高电平和低点平，并用PA6接收，但是好像不成功，特来请教大家，代码如下，谢谢大家

void TIM9_CH1_PWM_Init(u32 arr, u32 psc)
{
GPIO_InitTypeDef       GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef    TIM_OCInittructure;

RCC_APB1PeriphClockCmd(RCC_APB2Periph_TIM9, ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOE, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode  = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd  = GPIO_PuPd_DOWN;
GPIO_Init(GPIOE, &GPIO_InitStructure);

GPIO_PinAFConfig(GPIOE, GPIO_PinSource5, GPIO_AF_TIM9);

TIM_TimeBaseStructure.TIM_Prescaler    = psc;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseStructure.TIM_Period       = arr;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM9, &TIM_TimeBaseStructure);

TIM_OCInittructure.TIM_OCMode    = TIM_OCMode_PWM1;
TIM_OCInittructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInittructure.TIM_OCPolarity  = TIM_OCPolarity_High;
TIM_OC1Init(TIM9,&TIM_OCInittructure);

TIM_OC1PreloadConfig(TIM9, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM9, ENABLE);

TIM_Cmd(TIM9, ENABLE);
}

int main(void)
{
u16 ccnx = 2000;

NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
uart_init(115200);
delay_init(168);
TIM9_CH1_PWM_Init(6000-1, 42000-1);
TIM3_CH1_Cap_Init(6000-1, 84-1);

while(1)
{
delay_ms(1000);
if(ccnx == 2000)
ccnx=4000;
else if(ccnx == 4000)
ccnx=2000;
TIM_SetCompare1(TIM9, ccnx);
printf("%d\n", ccnx);
}
}