求助，STM32F407外部计数器模式，CNT的值一直为0，是我哪里设置的不对吗，直接上程序

open小哥 · 发表于 2018-4-20 17:22:53

//定时器配置为计数器
void TIM2_Cap_Init()
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM2 ,ENABLE);    //TIM5时钟使能
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE); //使能PORTA时钟

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 ; //GPIOA0
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN;//输入
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz; //速度100MHz
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; //浮空
GPIO_Init(GPIOA,&GPIO_InitStructure); //初始化PA0

TIM_DeInit(TIM2);

TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
TIM_TimeBaseStructure.TIM_Prescaler = 0x00;
TIM_TimeBaseStructure.TIM_ClockDivision = 0x00;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); // Time base configuration

TIM_ETRClockMode2Config(TIM2, TIM_ExtTRGPSC_OFF, TIM_ExtTRGPolarity_NonInverted, 0);

TIM_SetCounter(TIM2, 0);
TIM_Cmd(TIM2, ENABLE);

}

//主函数
u16 speed = 0;

int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);//设置系统中断优先级分组2
delay_init(168);  //初始化延时函数
uart_init(115200);//初始化串口波特率为115200

TIM14_PWM_Init(1000-1,840-1);    //84M/84=1Mhz的计数频率计数到500,PWM频率为1M/500=2Khz
TIM2_Init(0xFFFFFFFF,0);;
   while(1)
{

TIM_SetCompare1(TIM14,200);
speed=TIM2->CNT;
            printf("Freq = %d\r\n",speed);

delay_ms(1000);

}
}

open小哥 · 发表于 2018-4-20 17:22:54

问题解决了，分享一下，和F1不一样，F4计数器模式要配置成复用，我之前一直配置成输入。真的是很醉，发现自己以后要多看手册。顺便推荐一个软件，stmcubemx，很好用。
以下是定时器配置程序。
//定时器5通道1输入捕获配置
//arr：自动重装值(TIM2,TIM5是32位的!!)
//psc：时钟预分频数
void TIM2_Cap_Init(u32 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
GPIO_InitTypeDef  GPIO_InitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2,ENABLE);
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//100MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;//
GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_PinAFConfig(GPIOA,GPIO_PinSource0,GPIO_AF_TIM2);

TIM_TimeBaseInitStructure.TIM_Period = arr;
TIM_TimeBaseInitStructure.TIM_Prescaler=psc;
TIM_TimeBaseInitStructure.TIM_CounterMode=TIM_CounterMode_Up;
TIM_TimeBaseInitStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM2,&TIM_TimeBaseInitStructure);

TIM_TIxExternalClockConfig(TIM2, TIM_TIxExternalCLK1Source_TI1, TIM_ICPolarity_Rising, 0);

TIM_CounterModeConfig(TIM2,TIM_CounterMode_Up);
TIM_SetCounter(TIM2,0);
TIM_Cmd(TIM2,ENABLE);

}