stm32笔记:按键输入(精简版)

C代码

//GPIOA8是LED0

//GPIOA13是KEY0仅包含启动代码STM32F10x.s

#defineGPIOA_CRL(*(volatileunsignedlong*)(0x40000000+0x10000+0x0800+0x00))

#defineGPIOA_CRH(*(volatileunsignedlong*)(0x40000000+0x10000+0x0800+0x04))

#defineGPIOA_IDR(*(volatileunsignedlong*)(0x40000000+0x10000+0x0800+0x08))

#defineGPIOA_ODR(*(volatileunsignedlong*)(0x40000000+0x10000+0x0800+0x0C))

#defineRCC_APB2ENR(*(volatileunsignedlong*)(0x40000000+0x20000+0x1000+0x18))

voiddelay(unsignedlongi)//超级不精确的软延时

{

intj;

while(i--)

{

for(j=0;j<1500;j++)

{}

}

}

intmain(void)

{

u8keyflag=1;//按键进入标志,防止一次按键多次判断的简易做法

RCC_APB2ENR=1<<2;//打开PA时钟,默认启用内部8M时钟

GPIOA_CRH&=0XFFFFFFF0;//准备配置PA8,PA8是LED0

GPIOA_CRH|=0X00000003;//PA8推挽输出

GPIOA_ODR|=1<<8;//PA8输出高,即先关闭led

GPIOA_CRH&=0XFF0FFFFF;//准备配置PA13,PA13是KEY0

GPIOA_CRH|=0X00800000;//配置PA13为带上拉下拉输入

while(1)

{

if(!checkBit(GPIOA_IDR,13))//键被按下的话,执行led反转

{

if(keyflag)

{

keyflag=0;

GPIOA_ODR=revBit(GPIOA_ODR,8);//第8位反转,revBit是宏

}

}

else

{

keyflag=1;

}

delay(10);//简易消抖

}

}

//checkBit和revBit都是关于位的宏

//#defineBIT(n)(1<<(n))

//#definerevBit(val,n)((val)^(BIT(n)))

//#definecheckBit(val,n)(((val)&(BIT(n)))>>(n))