頭文件及完整例程下載：http://www.torrancerestoration.com/f/stm32標(biāo)準(zhǔn)例程庫函數(shù).rar
程序分析：
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程序分析：
#include "led.h" #include "delay.h"
#include "key.h"
#include "sys.h"
#include "usart.h"
#include "timer.h"
//ALIENTEK戰(zhàn)艦STM32開發(fā)板實驗10
//輸入捕獲實驗
//技術(shù)支持：www.openedv.com
//廣州市星翼電子科技有限公司
extern u8 TIM5CH1_CAPTURE_STA; //輸入捕獲狀態(tài)
extern u16 TIM5CH1_CAPTURE_VAL; //輸入捕獲值
int main(void)
{
u32 temp=0;
delay_init(); //延時函數(shù)初始化
NVIC_Configuration(); //設(shè)置NVIC中斷分組2:2位搶占優(yōu)先級，2位響應(yīng)優(yōu)先級
uart_init(9600); //串口初始化為9600
LED_Init(); //LED端口初始化
TIM3_PWM_Init(899,0); //不分頻。PWM頻率=72000/(899+1)=80Khz
TIM5_Cap_Init(0XFFFF,72-1); //以1Mhz的頻率計數(shù)
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)//成功捕獲到了一次上升沿
{
temp=TIM5CH1_CAPTURE_STA&0X3F;
temp*=65536;//溢出時間總和
temp+=TIM5CH1_CAPTURE_VAL;//得到總的高電平時間
printf("HIGH:%d us\r\n",temp);//打印總的高點平時間
TIM5CH1_CAPTURE_STA=0;//開啟下一次捕獲
}
}
}
初始化TIM3PWM時鐘和頻率，頻率為72M/900=80K,占空比為0 void TIM3_PWM_Init(u16 arr,u16 psc)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_AFIO, ENABLE); //使能GPIO外設(shè)和AFIO復(fù)用功能模塊時鐘使能
GPIO_PinRemapConfig(GPIO_PartialRemap_TIM3, ENABLE); //Timer3部分重映射 TIM3_CH2->PB5 //用于TIM3的CH2輸出的PWM通過該LED顯示
//設(shè)置該引腳為復(fù)用輸出功能,輸出TIM3 CH2的PWM脈沖波形
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; //TIM_CH2
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //復(fù)用推挽輸出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
//GPIO_WriteBit(GPIOA, GPIO_Pin_7,Bit_SET); // PA7上拉
TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)置在下一個更新事件裝入活動的自動重裝載寄存器周期的值 80K
TIM_TimeBaseStructure.TIM_Prescaler =psc; //設(shè)置用來作為TIMx時鐘頻率除數(shù)的預(yù)分頻值 不分頻
TIM_TimeBaseStructure.TIM_ClockDivision = 0; //設(shè)置時鐘分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數(shù)模式
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根據(jù)TIM_TimeBaseInitStruct中指定的參數(shù)初始化TIMx的時間基數(shù)單位
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //選擇定時器模式:TIM脈沖寬度調(diào)制模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比較輸出使能
TIM_OCInitStructure.TIM_Pulse = 0; //設(shè)置待裝入捕獲比較寄存器的脈沖值
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //輸出極性:TIM輸出比較極性高
TIM_OC2Init(TIM3, &TIM_OCInitStructure); //根據(jù)TIM_OCInitStruct中指定的參數(shù)初始化外設(shè)TIMx
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable); //使能TIMx在CCR2上的預(yù)裝載寄存器
TIM_ARRPreloadConfig(TIM3, ENABLE); //使能TIMx在ARR上的預(yù)裝載寄存器
TIM_Cmd(TIM3, ENABLE); //使能TIMx外設(shè)
} 設(shè)置TIM5為捕捉模式，先配置上升沿捕捉，頻率為72M/72=1M，溢出頻率為OXFFFF,允許溢出和捕捉中斷 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時鐘
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //使能GPIOA時鐘
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; //PA0 清除之前設(shè)置
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //PA0 輸入
GPIO_Init(GPIOA, &GPIO_InitStructure);
GPIO_ResetBits(GPIOA,GPIO_Pin_0); //PA0 下拉
//初始化定時器5 TIM5
TIM_TimeBaseStructure.TIM_Period = arr; //設(shè)定計數(shù)器自動重裝值
TIM_TimeBaseStructure.TIM_Prescaler =psc; //預(yù)分頻器
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //設(shè)置時鐘分割:TDTS = Tck_tim
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //TIM向上計數(shù)模式
TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure); //根據(jù)TIM_TimeBaseInitStruct中指定的參數(shù)初始化TIMx的時間基數(shù)單位
//初始化TIM5輸入捕獲參數(shù)
TIM5_ICInitStructure.TIM_Channel = TIM_Channel_1; //CC1S=01 選擇輸入端 IC1映射到TI1上
TIM5_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising; //上升沿捕獲
TIM5_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //映射到TI1上
TIM5_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1; //配置輸入分頻,不分頻
TIM5_ICInitStructure.TIM_ICFilter = 0x00;//IC1F=0000 配置輸入濾波器 不濾波
TIM_ICInit(TIM5, &TIM5_ICInitStructure);
//中斷分組初始化
NVIC_InitStructure.NVIC_IRQChannel = TIM5_IRQn; //TIM3中斷
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; //先占優(yōu)先級2級
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //從優(yōu)先級0級
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQ通道被使能
NVIC_Init(&NVIC_InitStructure); //根據(jù)NVIC_InitStruct中指定的參數(shù)初始化外設(shè)NVIC寄存器
TIM_ITConfig(TIM5,TIM_IT_Update|TIM_IT_CC1,ENABLE);//允許更新中斷 ,允許CC1IE捕獲中斷
TIM_Cmd(TIM5,ENABLE ); //使能定時器5
} TIM5中斷函數(shù)，TIM5CH1_CAPTURE_STA 為中斷次數(shù)，TIM5CH1_CAPTURE_VAL 為最后一次中斷讀取定時器時間，TIM5CH1_CAPTURE_STA&0X80 開啟捕捉 TIM5CH1_CAPTURE_STA&0X40 開啟下降沿捕捉 u8 TIM5CH1_CAPTURE_STA=0; //輸入捕獲狀態(tài)
u16 TIM5CH1_CAPTURE_VAL; //輸入捕獲值
//定時器5中斷服務(wù)程序
void TIM5_IRQHandler(void)
{
if((TIM5CH1_CAPTURE_STA&0X80)==0)//還未成功捕獲
{
if (TIM_GetITStatus(TIM5, TIM_IT_Update) != RESET)
{
if(TIM5CH1_CAPTURE_STA&0X40)//已經(jīng)捕獲到高電平了
{
if((TIM5CH1_CAPTURE_STA&0X3F)==0X3F)//高電平太長了
{
TIM5CH1_CAPTURE_STA|=0X80;//標(biāo)記成功捕獲了一次
TIM5CH1_CAPTURE_VAL=0XFFFF;
}else TIM5CH1_CAPTURE_STA++;
}
}
if (TIM_GetITStatus(TIM5, TIM_IT_CC1) != RESET)//捕獲1發(fā)生捕獲事件
{
if(TIM5CH1_CAPTURE_STA&0X40) //捕獲到一個下降沿
{
TIM5CH1_CAPTURE_STA|=0X80; //標(biāo)記成功捕獲到一次上升沿
TIM5CH1_CAPTURE_VAL=TIM_GetCapture1(TIM5);
TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Rising); //CC1P=0 設(shè)置為上升沿捕獲
}else //還未開始,第一次捕獲上升沿
{
TIM5CH1_CAPTURE_STA=0; //清空
TIM5CH1_CAPTURE_VAL=0;
TIM_SetCounter(TIM5,0);
TIM5CH1_CAPTURE_STA|=0X40; //標(biāo)記捕獲到了上升沿
TIM_OC1PolarityConfig(TIM5,TIM_ICPolarity_Falling); //CC1P=1 設(shè)置為下降沿捕獲
}
}
}
TIM_ClearITPendingBit(TIM5, TIM_IT_CC1|TIM_IT_Update); //清除中斷標(biāo)志位
} |