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ARM_day6:串口通信

1.实现字符串数据收发函数的封装

头文件:

#ifndef __UART4_H__
#define __UART4_H__

#include "stm32mp1xx_gpio.h"
#include "stm32mp1xx_rcc.h"
#include "stm32mp1xx_uart.h"

void uart4_config();
void putchar(char dat);
char getchar();
void puts(char *s);
void gets(char *s);

void led_init();
void LED1_CTRL(int flag);
void LED2_CTRL(int flag);
void LED3_CTRL(int flag);

int Strcmp(const char *dest,const char *src);

#endif

源文件:

#include "uart4.h"

void uart4_config()
{
    //使能GPIOB\GPIOG\UART4的外设时钟
    RCC->MP_AHB4ENSETR |= (0x1<<1);
    RCC->MP_AHB4ENSETR |= (0x1<<6);
    RCC->MP_APB1ENSETR |= (0x1<<16);
    //设置PG11和PB2为管脚复用功能
    //PG11
    GPIOG->MODER &= (~(0x3<<22));
    GPIOG->MODER |= (0x2<<22);
    //PB2
    GPIOG->MODER &= (~(0x3<<4));
    GPIOG->MODER |= (0x2<<4);
    //设置PG11为UART4_TX功能
    GPIOG->AFRH &= (~(0xf<<12));
    GPIOG->AFRH |= (0x6<<12);
    //设置PB2为UART4_RX功能
    GPIOB->AFRL &= (~(0xf<<8));
    GPIOB->AFRL |= (0x8<<8);
    //设置串口不使能
    USART4->CR1 &= (~0x1);
    //设置8位数据位
    USART4->CR1 &= (~(0x1<<12));
    USART4->CR1 &= (~(0x1<<28));
    //设置没有校验位
    USART4->CR1 &= (~(0x1<<10));
    //设置时钟频率不分频
    USART4->PRESC &= (~0xf);
    //设置16倍采样
    USART4->CR1 &= (~(0x1<<15));
    //设置1位停止位
    USART4->CR2 &= (~(0x3<<12));
    //设置波特率为115200
    USART4->BRR = 0x22b;
    //使能发送器
    USART4->CR1 |= (0x1<<3);
    //使能接收器
    USART4->CR1 |= (0x1<<2);
    //使能串口
    USART4->CR1 |= 0x1;
}

//发送单个字符
void putchar(char dat)
{
    //当发送寄存器中有数据时就一直阻塞
    while(!(USART4->ISR & (0x1<<7)));
    //反之没有数据则发送数据
    USART4->TDR = dat;
    //当发送的数据完成后结束发送
    while(!(USART4->ISR & (0x1<<6)));
}

//接收单个字符
char getchar()
{
    //当接收寄存器中没有数据时就一直阻塞
    while(!(USART4->ISR & (0x1<<5)));
    //有数据就返回
    return USART4->RDR;

}

//发送字符串
void puts(char *s)
{
    while(1)
    {
        if(*s=='\0')
        {
            break;
        }
        putchar(*s);
        s++;
    }
    //发送一个回车
    putchar('\n');
    putchar('\r');
    

}

//接收字符串
void gets(char *s)
{
    while(1)
     {
        //循环接收单个字符
        *s = getchar();
        //当检测到回车键‘\r’被按下,结束
        if(*s == '\r')
        {
            break;
        }
        putchar(*s);
        s++;

     }
     //在接收的字符串最后补上一个'\0'
     *s = '\0';
     //发送一个'\n'表示在串口工具下一行进行显示
     putchar('\n');
}

int Strcmp(const char *dest,const char *src)
{
    int i=0;
    while(*(dest+i) == *(src+i))
    {
        if(*(dest+i)=='\0')
        {
            break;
        }
        i++;
    }
    if(*(dest+i) - *(src+i) > 0)
    {
        return *(dest+i) - *(src+i);
    }
    else if(*(dest+i) - *(src+i) < 0)
    {
        return *(dest+i) - *(src+i);
    }
    else if(*(dest+i) - *(src+i) == 0)
    {
        return 0;
    }
}
#include "uart4.h"
void led_init()
{
    //使能外设时钟
    RCC->MP_AHB4ENSETR |= (0x3<<4);
    RCC->MP_APB2ENSETR |= 0x1;

    //设置PE10为输出
    GPIOE->MODER &= (~(0x3<<20));
    GPIOE->MODER |= (0x1<<20);
    //设置PF10为输出
    GPIOF->MODER &= (~(0x3<<20));
    GPIOF->MODER |= (0x1<<20);
    //设置PE8为输出
    GPIOE->MODER &= (~(0x3<<16));
    GPIOE->MODER |= (0x1<<16);
    //设置PE9为输出
    GPIOE->MODER &= (~(0x3<<18));
    GPIOE->MODER |= (0x1<<18);

    //设置PE10为推挽输出
    GPIOE->OTYPER &= (~(0x1<<10));
    //设置PF10为推挽输出
    GPIOF->OTYPER &= (~(0x1<<10));
    //设置PE8为推挽输出
    GPIOE->OTYPER &= (~(0x1<<8));
    //设置PE9为推挽输出
    GPIOE->OTYPER &= (~(0x1<<9));

    //设置PE10为低速输出
    GPIOE->OSPEEDR &= (~(0x3<<20));
    //设置PF10为低速输出
    GPIOF->OSPEEDR &= (~(0x3<<20));
    //设置PE8为低速输出
    GPIOE->OSPEEDR &= (~(0x3<<16));
    //设置PE9为低速输出
    GPIOE->OSPEEDR &= (~(0x3<<18));

    //设置PE10没有上拉下拉电阻
    GPIOE->PUPDR &= (~(0x3<<20));
    //设置PF10没有上拉下拉电阻
    GPIOF->PUPDR &= (~(0x3<<20));
    //设置PE8没有上拉下拉电阻
    GPIOE->PUPDR &= (~(0x3<<16));
    //设置PE9没有上拉下拉电阻
    GPIOE->PUPDR &= (~(0x3<<18));

    //默认三盏灯为熄灭状态
    GPIOE->ODR &= (~(0x1<<10));
    GPIOF->ODR &= (~(0x1<<10));
    GPIOE->ODR &= (~(0x1<<8));
    //风扇
    GPIOE->ODR &= (~(0x1<<9));

}
void LED1_CTRL(int flag)
{
    if(flag == 1)//亮灯
    {
        GPIOE->ODR |= (0x1<<10);
    }
    else if(flag == 0)//灭灯
    {
        GPIOE->ODR &= (~(0x1<<10));
    }

}
void LED2_CTRL(int flag)
{
    if(flag == 1)//亮灯
    {
        GPIOF->ODR |= (0x1<<10);
    }
    else if(flag == 0)//灭灯
    {
        GPIOF->ODR &= (~(0x1<<10));
    }

}
void LED3_CTRL(int flag)
{
    if(flag == 1)//亮灯
    {
        GPIOE->ODR |= (0x1<<8);
    }
    else if(flag == 0)//灭灯
    {
        GPIOE->ODR &= (~(0x1<<8));
    }

}
void CH1_CTRL(int flag)
{
    if(flag == 1)//亮灯
    {
        GPIOE->ODR |= (0x1<<9);
    }
    else if(flag == 0)//灭灯
    {
        GPIOE->ODR &= (~(0x1<<9));
    }
}

 

主函数:

#include "uart4.h"

//手动封装一个延时函数
void delay(int ms)
{
int i,j;
for(i=0;i<ms;i++)
{

for(j=0;j<2000;j++)
{

}
}

}
int main()
{
//uart4的初始化
uart4_config();
led_init();
//存储单个字符的容器
//char a;
//存储字符串的容器
char buf[128];
while(1)
{
/*
a = getchar();//接收一个字符
putchar(a+1);//发送一个字符,eg:发送a,输出b
putchar('\r');
    putchar('\n');
*/
/*
gets(buf);//接收字符串
puts(buf);//发送字符串
*/
/*串口发送指令,使得LED灯/风扇工作*/
gets(buf);
if(Strcmp(buf,"LED1_ON") == 0)
{
LED1_CTRL(1);
}
else if(Strcmp(buf,"LED1_OFF") == 0)
{
LED1_CTRL(0);
}
else if(Strcmp(buf,"LED2_ON") == 0)
{
LED2_CTRL(1);
}
else if(Strcmp(buf,"LED2_OFF") == 0)
{
LED2_CTRL(0);
}
else if(Strcmp(buf,"LED3_ON") == 0)
{
LED3_CTRL(1);
}
else if(Strcmp(buf,"LED3_OFF") == 0)
{
LED3_CTRL(0);
}
else if(Strcmp(buf,"CH1_ON") == 0)
{
CH1_CTRL(1);
}
else if(Strcmp(buf,"CH1_OFF") == 0)
{
CH1_CTRL(0);
}
puts(buf);

}
return 0;
}

 

2.通过串口发送指令,控制LED\风扇等外设工作

#include "uart4.h"

//手动封装一个延时函数
void delay(int ms)
{
int i,j;
for(i=0;i<ms;i++)
{

for(j=0;j<2000;j++)
{

}
}

}
int main()
{
//uart4的初始化
uart4_config();
led_init();
//存储单个字符的容器
//char a;
//存储字符串的容器
char buf[128];
while(1)
{
/*
a = getchar();//接收一个字符
putchar(a+1);//发送一个字符,eg:发送a,输出b
putchar('\r');
    putchar('\n');
*/
/*
gets(buf);//接收字符串
puts(buf);//发送字符串
*/
/*串口发送指令,使得LED灯/风扇工作*/
gets(buf);
if(Strcmp(buf,"LED1_ON") == 0)
{
LED1_CTRL(1);
}
else if(Strcmp(buf,"LED1_OFF") == 0)
{
LED1_CTRL(0);
}
else if(Strcmp(buf,"LED2_ON") == 0)
{
LED2_CTRL(1);
}
else if(Strcmp(buf,"LED2_OFF") == 0)
{
LED2_CTRL(0);
}
else if(Strcmp(buf,"LED3_ON") == 0)
{
LED3_CTRL(1);
}
else if(Strcmp(buf,"LED3_OFF") == 0)
{
LED3_CTRL(0);
}
else if(Strcmp(buf,"CH1_ON") == 0)
{
CH1_CTRL(1);
}
else if(Strcmp(buf,"CH1_OFF") == 0)
{
CH1_CTRL(0);
}
puts(buf);

}
return 0;
}


原文地址:https://blog.csdn.net/FS223107/article/details/137794318

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