[嵌入式]STM32F103—使用通用定时器控制开关

STM32F103系列的单片机一共有11个定时器，其中：
2个高级定时器、4个普通定时器、2个基本定时器、2个看门狗定时器、1个系统嘀嗒定时器

在除去看门狗定时器和系统滴答定时器的八个定时器中：
TIM1和TIM8是高级定时器，支持向上，向下，向上/向下这3种计数模式。
TIM2-TIM5是通用定时器，支持向上，向下，向上/向下这3种计数模式。
TIM6和TIM7是基本的定时器，支持向上这种计数模式。

timer.c

#include "timer.h"

struct Tim3_Delay tim3_delay = 
{
0,0,
0,0
};

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
	
	//定时器TIM8初始化
	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 Tout=（（arr+1）* (psc+1) )/72000
	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(TIM3, &TIM_TimeBaseStructure); //根据指定的参数初始化TIMx的时间基数单位
 
	TIM_ITConfig(TIM3,TIM_IT_Update,ENABLE ); //使能指定的TIM7中断,允许更新中断

	//中断优先级NVIC设置
	NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;  //TIM7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);  //初始化NVIC寄存器

	TIM_Cmd(TIM3, ENABLE);  //使能TIMx					 

}

void TIM3_IRQHandler(void)
{  
	if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)  //检查TIM7更新中断发生与否
	{  		
		tim3_delay.count_8ms ++;
		if(tim3_delay.count_8ms % 5 == 0)
			tim3_delay.count_40ms ++;
		if(tim3_delay.count_8ms % 100 == 0)
			tim3_delay.count_800ms ++;	 
		
		TIM_ClearITPendingBit(TIM3, TIM_IT_Update  );  //清除TIMx更新中断标志 z	 	
	}
} 

timer.h

#ifndef __TIMER_H
#define __TIMER_H

#include "stm32f10x.h"
#include <sys.h>	 

struct Tim3_Delay
{
	u32 count_8ms;
	u32 last_count_8ms;
	u32 count_40ms;
	u32 last_count_40ms;
	u32 count_800ms;
	u32 last_count_800ms;
};

extern struct Tim3_Delay tim3_delay;

void TIM3_Int_Init(u16 arr,u16 psc);
void TIM3_IRQHandler(void);

#endif

key.c

#include "key.h"

u16 KeyPressDown = 0x0000;//按下的键值  
u16 KeyRelease   = 0x0000;//弹起的键值  
u16 LastKey	   	 = 0x0000;//上一次的键值  

void Key_Init(void)
{
	GPIO_InitTypeDef GPIO_InitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11 | GPIO_Pin_12;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOE,&GPIO_InitStructure);
	
	GPIO_WriteBit(GPIOE, GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11 | GPIO_Pin_12, Bit_SET);
	
	KeyPressDown = 0;
	KeyRelease   = 0;
	LastKey      = 0;

//	Key_Port |= Key_Mask;//将按键对应的IO设置为输入状态  
}

//按键扫描，定时10ms执行一次  
void Key_Scan(void)  
{     
    //当前读取的键值  
    u16 CurrKey;
    //当按键1即A4按下11110xxxx
	 //1110xxxx取反后00011111与上11110000得到00010000此时转换成16进制数字为0x10
    CurrKey = (~Key_Port) & Key_Mask;  
    //11111111与上00010000得到0x10
    KeyPressDown = (~LastKey) & CurrKey;  
	   
    KeyRelease = LastKey & (~CurrKey);  
   
    LastKey = CurrKey;  
}

key.h

#ifndef __KEY_H
#define __KEY_H	 

#include "sys.h"

#define Key1_Value   0x0200 
#define Key2_Value   0x0400
#define Key3_Value   0x0800
#define Key4_Value   0x1000

#define Key_Mask    0x1E00
#define Key_Port   (GPIO_ReadInputData(GPIOE) & Key_Mask)//先将A4567四个位全部置高，如果按键按下，则那一位置0，与上Key_Mask则按下的那一按键置高，其余置0
														 //如按键1，A4至低返回1110xxxx与上11110000得到按下的脚位，其余位保持和置低

void Key_Init(void);
void Key_Scan(void);

extern u16 KeyPressDown;//按下的键值  
extern u16 KeyRelease;//弹起的键值  
extern u16 LastKey;//上一次的键值  	
			    
#endif

main.c

#include "SysTick.h"
#include "key.h"
#include "sys.h"
#include "timer.h"

int main(void)
{	
	SysTick_Init(72);	    	 //延时函数初始化
	Key_Init();
	
	TIM3_Int_Init(79,7199); //=====	（8ms）中断	计算公式如下：溢出时间（单位为 us）= ((arr+1)*(psc+1 ))/输入时钟频率（单位为 Mhz）；

	while(1)
	{
		if(tim3_delay.last_count_8ms != tim3_delay.count_8ms)
		{
			Key_Scan();
			tim3_delay.last_count_8ms = tim3_delay.count_8ms;
		}
		if(KeyPressDown == Key1_Value)//按键1
		{
			KeyPressDown = 0;
		}
		if(KeyPressDown == Key2_Value)//按键2
		{
			KeyPressDown = 0;
		}

	}
}

STM32F103C8T6基本功能代码_墨云景阳的博客-CSDN博客_stm32f103c8t6代码