本程序对应的开发板为蓝桥杯嵌入式开发板stm32f103rbt6,为中型mcu。本程序用TIM1通道2(PA9)输出1kHz、占空比为25%的矩形波,并用TIM2(PA1)测量矩形波周期和脉冲宽度。
初始化程序
//TIM1通道2(PA9)输出矩形波初始化子程序 频率1kHz,(72000000/(999+1)*(71+1))占空比25% (249+1)/(999+1)
void TIM1_OCInit(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
TIM_TimeBaseStructure.TIM_Period = 999;
TIM_TimeBaseStructure.TIM_Prescaler = 71;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_RepetitionCounter=0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 250;
TIM_OCInitStructure.TIM_OCNIdleState=TIM_OutputNState_Disable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC2Init(TIM1, &TIM_OCInitStructure);
TIM_CtrlPWMOutputs(TIM1,ENABLE);
TIM_Cmd(TIM1,ENABLE);
}
//tim2通道2(pa1)测量矩形波周期和脉冲宽度初始化子程序
void TIM2_ICInit(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_ICInitTypeDef TIM_ICInitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA, &GPIO_InitStructure);
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 71;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM_ICInitStructure.TIM_ICFilter = 0;
TIM_PWMIConfig(TIM2, &TIM_ICInitStructure);
TIM_SelectSlaveMode(TIM2,TIM_SlaveMode_Reset);
TIM_SelectInputTrigger(TIM2,TIM_TS_TI2FP2);
TIM_Cmd(TIM2, ENABLE);
}
捕获程序
//TIM2测量方波周期和脉冲处理子程序
unsigned char TIM2_Cap(unsigned int* puiTim_Val)
{
if(TIM_GetFlagStatus(TIM2,TIM_FLAG_CC2))
{
puiTim_Val[0]=TIM_GetCapture2(TIM2)+1;
puiTim_Val[1]=TIM_GetCapture1(TIM2)+1;
return 1;
}
return 0;
}
显示函数
void TIM_Proc(void)
{
if(ucSec!=ucSec1)
{
ucSec1=ucSec;
TIM2_Cap(uiTim_Val);
sprintf((char*)string,"sec:%3u %4u %1ums",ucSec,uiTim_Val[0],uiTim_Val[0]/1000);
LCD_DisplayStringLine(Line1,string);
sprintf((char*)string,"%4u %2u%%",uiTim_Val[1],uiTim_Val[1]*100/uiTim_Val[0]);
LCD_DisplayStringLine(Line3,string);
}
}
滴答定时器
void SysTick_Handler(void)
{
TimingDelay--;
ulTick_ms++;
if(ulTick_ms%1000==0)
{
ucSec++;
}
}
主程序
#include "stm32f10x.h"
#include "lcd.h"
#include "stdio.h"
u32 TimingDelay = 0;
void Delay_Ms(u32 nTime);
void TIM1_OCInit(void);
void TIM2_ICInit(void);
unsigned char TIM2_Cap(unsigned int* puiTim_Val);
void TIM_Proc(void);
unsigned long ulTick_ms=0;
unsigned char ucSec=0,ucSec1=0;
unsigned int uiTim_Val[2];
u8 string[20];
int main(void)
{
STM3210B_LCD_Init();
LCD_Clear(Blue);
LCD_SetBackColor(Blue);
LCD_SetTextColor(White);
SysTick_Config(SystemCoreClock/1000);
TIM1_OCInit();
TIM2_ICInit();
LCD_DisplayStringLine(Line0," ");
LCD_DisplayStringLine(Line1," ");
LCD_DisplayStringLine(Line2," ");
LCD_DisplayStringLine(Line3," ");
LCD_DisplayStringLine(Line4," ");
LCD_DisplayStringLine(Line5," ");
LCD_DisplayStringLine(Line6," ");
LCD_DisplayStringLine(Line7," ");
LCD_DisplayStringLine(Line8," ");
LCD_DisplayStringLine(Line9," ");
while (1)
{
TIM_Proc();
}
}
void Delay_Ms(u32 nTime)
{
TimingDelay = nTime;
while(TimingDelay != 0);
}