STM32F103 读取传感器数据PWM

只看该作者 · 2015-10-21 21:21

以下是PWM.c

#include "pwm.h"

void TIM3_PWM_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
TIM_OCInitTypeDef  TIM_OCInitStructure;
TIM_ICInitTypeDef  TIM_ICInitStructure;

RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA  | RCC_APB2Periph_AFIO, ENABLE);  //Ê¹ÄÜGPIOÍâÉèºÍAFIO¸´ÓÃ¹¦ÄÜÄ£¿éÊ±ÖÓÊ¹ÄÜ

  //ÉèÖÃ¸ÃÒý½ÅÎª¸´ÓÃÊä³ö¹¦ÄÜ,Êä³öTIM3 CH3==>PB0  CH4==>PB1 µÄPWMÂö³å²¨ÐÎ
GPIO_InitStructure.GPIO_Pin =GPIO_Pin_7; //³õÊ¼»¯GPIO
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  //¸´ÓÃÍÆÍìÊä³ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;                //Í¨µÀÉèÖÃ
  TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;    //ÉÏÉýÑØ´¥·¢
  TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; //¹Ü½ÅÓë¼Ä´æÆ÷¶ÔÓ¦¹ØÏµ
  TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;          //ÊäÈëÔ¤·ÖÆµ¡£ÒâË¼ÊÇ¿ØÖÆÔÚ¶àÉÙ¸öÊäÈëÖÜÆÚ×öÒ»´ÎÊäÈëºÍÐÅºÅÆµÂÊÃ»ÓÐ±ä£¬²âµÃµÄÖÜÆÚÒ²²»»á±ä£
  //±ÈÈçÑ¡Ôñ4·ÖÆµÔòÃ¿ËÄ¸öÊäÈëÖÜÆÚ²Å×öÒ»´Î²¶»ñ£¬ÕâÑùÔÚÊäÈëÐÅºÅ±ä»¯²»Æµ·±µÄÇé¿öÏÂ£¬¿ÉÒÔ¼õÉÙÈí¼þ±»²»¶ÏÖÐ¶ÏµÄ´ÎÊý¡£
  TIM_ICInitStructure.TIM_ICFilter = 0x0;                         //ÂË²¨ÉèÖÃ£¬¾Àú¼¸¸öÖÜÆÚÌø±äÈÏ¶¨²¨ÐÎÎÈ¶¨0x0~0xf
  TIM_PWMIConfig(TIM3, &TIM_ICInitStructure);                      //¸ù¾Ý²ÎÊýÉèÖÃTIMÍâÉèÐÅÏ¢
  TIM_SelectInputTrigger(TIM3, TIM_TS_TI2FP2);                   //Ñ¡ÔñIC2ÎªÊ¼ÖÕ´¥·¢Ô´
  TIM_SelectSlaveMode(TIM3, TIM_SlaveMode_Reset);    //TIM´ÓÄ£Ê½£º´¥·¢ÐÅºÅµÄÉÏÉýÖØÐÂ³õÊ¼»¯¼ÆÊýÆ÷ºÍ´¥·¢¼Ä´æÆ÷µÄ¸üÐÂÊÂ¼þ
  TIM_SelectMasterSlaveMode(TIM3, TIM_MasterSlaveMode_Enable); //Æô¶¯¶¨Ê±Æ÷µÄ±»¶¯´¥·¢
  TIM_Cmd(TIM3, ENABLE);                                           //Æô¶¯TIM3
  TIM_ITConfig(TIM3, TIM_IT_CC2, ENABLE);                         //´ò¿ªÖÐ¶Ï
}

u16 IC2Value = 0;
u16 DutyCycle = 0;
u16 Frequency = 0;

void TIM3_IRQHandler(void)
{
TIM_ClearITPendingBit(TIM3,TIM_IT_CC2);//Çå³ýTIMµÄÖÐ¶Ï´ý´¦ÀíÎ»
IC2Value=TIM_GetCapture2(TIM3);  //¶ÁÈ¡IC2²¶»ñ¼Ä´æÆ÷µÄÖµ£¬¼´ÎªPWMÖÜÆÚµÄ¼ÆÊýÖµ
if(IC2Value!=0)
{
DutyCycle=(TIM_GetCapture1(TIM3)*100)/IC2Value;    //¶ÁÈ¡IC1²¶»ñ¼Ä´æÆ÷µÄÖµ£¬²¢¼ÆËãÕ¼¿Õ±È
Frequency=72000000/IC2Value; //¼ÆËãPWMÆµÂÊ
}
else
{
DutyCycle=0;
Frequency=0;
}

}

以下是main.c

#include "delay.h"
#include "sys.h"
#include "usart.h"
#include "exti.h"
#include "wdg.h"
#include "pwm.h"

extern void TIM3_IRQHandler(void);
extern void TIM3_PWM_Init(void);
extern u16 IC2Value;
extern u16 DutyCycle ;
extern u16 Frequency ;

int main(void)
{

SystemInit();
delay_init(72);          //ÑÓÊ±³õÊ¼»¯
NVIC_Configuration();    //ÖÐ¶ÏÅäÖÃ
uart_init(9600); //´®¿Ú³õÊ¼»¯

while(1)
{
delay_ms(1004);
   if(!IC2Value)
{
printf("CO2    = %d\r\n",DutyCycle);
printf("CO2 = %d\r\n",Frequency);
}
}

}

为何读取不到数据呢？用的是PA7 TIM3_CH2