嵌入式系统stm32 跑马灯实验

Posted 2022-02-07 Ice丨shine

一、实验目的和实验要求

实验要求：短按实验板扩展板上的按键SW18，依次点亮核心板上D2-D4指示灯。长按按键2秒，实现四个灯循环点亮（跑马灯）。

二、实验原理

如上图所示，四个 LED 正极通过电阻连接到电源+3.3V，LED 负端连接到 CPU 的 PEx
引脚。由此可知，只需要通过 CPU 控制 PEx 引脚为低电平，对应的指示灯即可点亮，如果
控制 PEx 引脚为高电平，这对应的 LED 熄灭。通过程序循环扫描，即可实现跑马灯控制。

三、实验结果

#include "stm32f10x.h"

#define RCC_APB2ENR         (*((volatile unsigned int*)0x40021018))  
#define GPIOE_CRH           (*((volatile unsigned int*)0x40011804))  
#define GPIOE_BSRR          (*((volatile unsigned int*)0x40011810))   
#define GPIOE_IDR           (*((volatile unsigned int*)0x40011808))   // ¶Ë¿ÚÊäÈëÊý¾Ý¼Ä´æÆ÷	
#define GPIOE_ODR           (*((volatile unsigned int*)0x4001180C))   
	
#define GPIOB_CRL           (*((volatile unsigned int*)0x40010C00))   
#define GPIOB_IDR           (*((volatile unsigned int*)0x40010C08))  

void LED_Init(void)

	RCC_APB2ENR |= 1<<6;         
	GPIOE_CRH &=0XFFFF0000;      
	GPIOE_CRH |=0x3333;			        

	GPIOE_BSRR |= 1<<8;           
	GPIOE_BSRR |= 1<<9;           
	GPIOE_BSRR |= 1<<10;           
	GPIOE_BSRR |= 1<<11;           


void Delay(unsigned int nCount)
 
  while(nCount > 0)
   
  	  nCount --;   
  

int count=0;
void LED_Turn(void)
//通过count判断现在四个灯的状态，并完成切换
	if(count==1)
		GPIOE_BSRR |= 1<<8; 
		GPIOE_BSRR |= 1<<25; 
		count++;
		Delay(0xfffff);
		Delay(0xfffff);
	else if(count==2)
		GPIOE_BSRR |= 1<<9;
		GPIOE_BSRR |= 1<<26;
		count++;
		Delay(0xfffff);
		Delay(0xfffff);
	else if(count==3)
		GPIOE_BSRR |= 1<<10; 
		GPIOE_BSRR |= 1<<27;
		count++;
		Delay(0xfffff);
		Delay(0xfffff);
	else if(count==4)
		GPIOE_BSRR |= 1<<11; 
		GPIOE_BSRR |= 1<<24; 
		count=1;
		Delay(0xfffff);
		Delay(0xfffff);
	else
		GPIOE_BSRR |= 1<<24;
		count++;
		Delay(0xfffff);
		Delay(0xfffff);
	


//跑马灯控制函数，让4个灯轮流亮，最后全部重置熄灭
void LED_Turn_Run(void)

	
	while(1)
	
		GPIOE_BSRR &= ~(1<<8);      
		GPIOE_BSRR |= 1<<24;        
		Delay(0xfffff);
		Delay(0xfffff);
		GPIOE_BSRR |= 1<<25;        
		Delay(0xfffff);
		Delay(0xfffff);
		GPIOE_BSRR |= 1<<26;        
		Delay(0xfffff);
		Delay(0xfffff);
		GPIOE_BSRR |= 1<<27;        
		Delay(0xfffff);
		Delay(0xfffff);
	
	  GPIOE_BSRR |= 1<<8; 
		GPIOE_BSRR |= 1<<9;           
		GPIOE_BSRR |= 1<<10;            
		GPIOE_BSRR |= 1<<11;           
		
		Delay(0xfffff);
		Delay(0xfffff);
	



void KEY_Init(void)

		RCC_APB2ENR |=1<<3;    
		GPIOB_CRL |=0X04000000;


//static u8  fac_us=0;									
void delay_us(u32 nus)
		
		int i,cnt ;
		cnt = nus<<1  ;
		for ( i = 0 ; i < cnt ; i++ );
	

void delay_ms(u16 nms)
	 		  	  
	int i ;
	for( i = 0 ; i < nms; i ++ )
		delay_us(1000) ;
 

u8 KEY_Scan(void)
	 
	//键盘扫描，单按返回1，长按返回2
	u8 key_1= 0;
	int flag=0;//通过flag记录按键时间长短
	if(GPIOB_IDR & 0x40)
			key_1=1;
	else 
  		key_1=0;
	if(key_1==0)
				
				delay_ms(100); 
				if(key_1!=0) return 0;
			 
	while(key_1==0) 
			flag++;
			Delay(0xfffff);
			if(flag >= 15) return 2;//flag达到15则判定为长按
		
			if(GPIOB_IDR & 0x40)
					key_1=1;
			else 
					key_1=0;
			if(key_1==0)
			
				delay_ms(100); 
				if(key_1!=0) break;
			 
	
	if(flag>0) return 1;//flag大于0但是没达到15判定为短按
 	return 0;


int main(void)

	u8 t=0;
	BoardInit();
	LED_Init();
	KEY_Init();
	while(1)
	
			t=KEY_Scan();
			if(t==1)//在main函数中进行判断按键状态
			
				LED_Turn();
			else if(t==2)
			
				LED_Turn_Run();
			
	
	return 1;