标题:
stm32学习:按键输入(精简版)
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作者:
51黑电子迷
时间:
2017-2-9 22:30
标题:
stm32学习:按键输入(精简版)
//GPIOA8是 LED0
//GPIOA13是 KEY0 仅包含启动代码 STM32F10x.s
#define GPIOA_CRL (*(volatile unsigned long *)(0x40000000+0x10000+0x0800+0x00))
#define GPIOA_CRH (*(volatile unsigned long *)(0x40000000+0x10000+0x0800+0x04))
#define GPIOA_IDR (*(volatile unsigned long *)(0x40000000+0x10000+0x0800+0x08))
#define GPIOA_ODR (*(volatile unsigned long *)(0x40000000+0x10000+0x0800+0x0C))
#define RCC_APB2ENR (*(volatile unsigned long *)(0x40000000+0x20000+0x1000+0x18))
void delay(unsigned long i) //超级不精确的软延时
{
int j;
while(i--)
{
for(j=0;j<1500;j++)
{}
}
}
int main(void)
{
u8 keyflag=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
//#define BIT(n) (1<<(n))
//#define revBit(val,n) ((val)^(BIT(n)))
//#define checkBit(val,n) (((val)&(BIT(n)))>>(n))
复制代码
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