我用的是定时器和输入捕获
timer.h
#include "timer.h"
#include "led.h"
#include "usart.h"
u16 b=0;
extern double d;
void TIM3_Int_Init(u16 arr,u16 psc)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //时钟使能
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值 计数到5000为500ms
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值 10Khz的计数频率
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE ); //使能指定的TIM3中断,允许更新中断
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn; //TIM3中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //先占优先级0级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //从优先级3级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器
TIM_Cmd(TIM3, ENABLE); //使能TIMx外设
}
//定时器3中断服务程序
void TIM3_IRQHandler(void) //TIM3中断
{
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET) //检查指定的TIM中断发生与否:TIM 中断源
{
TIM_ClearITPendingBit(TIM3, TIM_IT_Update ); //清除TIMx的中断待处理位:TIM 中断源
d=b;//
b=0;
}
}
//TIM3 PWM部分初始化
//PWM输出初始化
//arr:自动重装值
//psc:时钟预分频数
void TIM2_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE); //使能定时器3时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_AFIO, ENABLE); //使能GPIO外设和AFIO复用功能模块时钟
GPIO_PinRemapConfig(GPIO_PartialRemap2_TIM2, ENABLE); //Timer3部分重映射 TIM3_CH2->PB5
//设置该引脚为复用输出功能,输出TIM3 CH2的PWM脉冲波形 GPIOB.5
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1; //TIM_CH2
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIO
//初始化TIM3
TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
//初始化TIM3 Channel2 PWM模式
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //选择定时器模式:TIM脉冲宽度调制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出极性:TIM输出比较极性高
TIM_OC2Init(TIM2, &TIM_OCInitStructure); //根据T指定的参数初始化外设TIM3 OC2
TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Enable); //使能TIM3在CCR2上的预装载寄存器
TIM_Cmd(TIM2, ENABLE); //使能TIM3
}
TIM_ICInitTypeDef TIM5_ICInitStructure;
void TIM5_Cap_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5, ENABLE); //使能TIM5时钟
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //使能GPIOA时钟
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //PA0 清除之前设置
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //PA0 输入
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_ResetBits(GPIOA,GPIO_Pin_0); //PA0 下拉
//初始化定时器5 TIM5
TIM_TimeBaseStructure.TIM_Period = arr; //设定计数器自动重装值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //预分频器
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上计数模式
TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure); //根据TIM_TimeBaseInitStruct中指定的参数初始化TIMx的时间基数单位
//初始化TIM5输入捕获参数
TIM5_ICInitStructure.TIM_Channel = TIM_Channel_1; //CC1S=01 选择输入端 IC1映射到TI1上
TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕获
TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上
TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置输入分频,不分频
TIM5_ICInitStructure.TIM_ICFilter= 0x00;//IC1F=0000 配置输入滤波器 不滤波
TIM_ICInit(TIM5, &TIM5_ICInitStructure);
//中断分组初始化
NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn; //TIM3中断
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; //先占优先级2级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //从优先级0级
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //根据NVIC_InitStruct中指定的参数初始化外设NVIC寄存器
TIM_ITConfig(TIM5,TIM_IT_Update|TIM_IT_CC1,ENABLE);//允许更新中断 ,允许CC1IE捕获中断
TIM_Cmd(TIM5,ENABLE ); //使能定时器5
}
u8 TIM5CH1_CAPTURE_STA=0; //输入捕获状态
u16 TIM5CH1_CAPTURE_VAL; //输入捕获值
//定时器5中断服务程序
void TIM5_IRQHandler(void)
{
if((TIM5CH1_CAPTURE_STA&0X80)==0)//还未成功捕获
{
if (TIM_GetITStatus(TIM5, TIM_IT_CC1) != RESET)//捕获1发生捕获事件
{
if(TIM5CH1_CAPTURE_STA&0X40) //捕获到一个下降沿
{
TIM5CH1_CAPTURE_STA|=0X80; //标记成功捕获到一次高电平脉宽
TIM5CH1_CAPTURE_VAL=TIM_GetCapture1(TIM5);
TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Rising); //CC1P=0 设置为上升沿捕获
b++;
}else //还未开始,第一次捕获上升沿
{
TIM5CH1_CAPTURE_STA=0; //清空
TIM5CH1_CAPTURE_VAL=0;
TIM_SetCounter(TIM5,0);
TIM5CH1_CAPTURE_STA|=0X40; //标记捕获到了上升沿
TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Falling); //CC1P=1 设置为下降沿捕获
}
}
}
TIM_ClearITPendingBit(TIM5, TIM_IT_CC1|TIM_IT_Update); //清除中断标志位
}
main.c
#include "led.h"
#include "delay.h"
#include "key.h"
#include "sys.h"
#include "usart.h"
#include "timer.h"
#include "beep.h"
#include "oled.h"
double n=0;
extern u8 TIM5CH1_CAPTURE_STA; //输入捕获状态
extern u16 TIM5CH1_CAPTURE_VAL; //输入捕获值
extern u16 b;
double t,m,n,k,s,d;
int main(void)
{
u32 temmp=0;
t=0;
m=0;
n=0;
k=0;
s=0;
d=0;
delay_init();
BEEP_Init(); //延时函数初始化
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //设置NVIC中断分组2:2位抢占优先级,2位响应优先级
uart_init(115200); //串口初始化为115200
LED_Init();
KEY_Init();
OLED_Init(); //初始化OLED
OLED_Clear(); //LED端口初始化
TIM3_Int_Init(9999,7199);//10Khz的计数频率,计数到5000为1s
TIM2_PWM_Init(8999,0);
TIM5_Cap_Init(0XFFFF,72-1); //以1Mhz的频率计数 1ms
while(1)
{
delay_ms(10);
TIM_SetCompare2(TIM3,TIM_GetCapture2(TIM3)+1);
if(TIM_GetCapture2(TIM3)==300)TIM_SetCompare2(TIM3,0);
if(TIM5CH1_CAPTURE_STA&0X80)//成功捕获到了一次上升沿
{
temmp=TIM5CH1_CAPTURE_STA&0X3F;
temmp*=65536;//溢出时间总和
temmp+=TIM5CH1_CAPTURE_VAL;//得到总的高电平时间
OLED_ShowCHinese(0,0,9);//实
OLED_ShowCHinese(15,0,10);//时
OLED_ShowCHinese(30,0,11);//速
OLED_ShowCHinese(45,0,12);//度
OLED_ShowCHinese(60,0,13);//:
//OLED_ShowString(95,0,"km/h");
OLED_ShowNum(74,0,d,2,16);
delay_ms(10);
TIM5CH1_CAPTURE_STA=0;//开启下一次捕获
}
测出来的速度会跳变?大家帮我看看是不是程序哪里出现了问题?
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