ARM 串口通信点灯

led.h

l

#ifndef __LED_H__
#define __LED_H__

#define RCC_GPIO (*(unsigned int *)0x50000a28)
#define GPIOE_MODER (*(unsigned int *)0x50006000)
#define GPIOF_MODER (*(unsigned int *)0x50007000)
#define GPIOE_OTYPER (*(unsigned int *)0x50006004)
#define GPIOF_OTYPER (*(unsigned int *)0x50007004)
#define GPIOE_OSPEEDR (*(unsigned int *)0x50006008)
#define GPIOF_OSPEEDR (*(unsigned int *)0x50007008)
#define GPIOE_PUPDR (*(unsigned int *)0x5000600C)
#define GPIOF_PUPDR (*(unsigned int *)0x5000700c)
#define GPIOE_ODR (*(unsigned int *)0x50006014)
#define GPIOF_ODR (*(unsigned int *)0x50007014)

void all_led_init();
void led1_on();
void led1_off();
void led2_on();
void led2_off();
void led3_on();
void led3_off();

#endif

led.c 

#include "led.h"
void all_led_init()
{
    RCC_GPIO |= (0X3<<4);//时钟使能
    GPIOE_MODER &=(~(0X3<<20));//设置PE10输出
    GPIOE_MODER |= (0X1<<20);
    //设置PE10为推挽输出
    GPIOE_OTYPER &=(~(0x1<<10));
    //PE10为低速输出
    GPIOE_OSPEEDR &= (~(0x3<<20));
    //设置无上拉下拉
    GPIOE_PUPDR &= (~(0x3<<20));

    //LED2
    GPIOF_MODER &=(~(0X3<<20));//设置Pf10输出
    GPIOF_MODER |= (0X1<<20);
    //设置Pf10为推挽输出
    GPIOF_OTYPER &=(~(0x1<<10));
    //Pf10为低速输出
    GPIOF_OSPEEDR &= (~(0x3<<20));
    //设置无上拉下拉
    GPIOF_PUPDR &= (~(0x3<<20));

    //LED3
    GPIOE_MODER &=(~(0X3<<16));//设置PE8输出
    GPIOE_MODER |= (0X1<<16);
    //设置PE8为推挽输出
    GPIOE_OTYPER &=(~(0x1<<8));
    //PE8为低速输出
    GPIOE_OSPEEDR &= (~(0x3<<16));
    //设置无上拉下拉
    GPIOE_PUPDR &= (~(0x3<<16));
}
void led1_on()
{
    GPIOE_ODR |= (0x1<<10);
}

void led1_off()
{
    GPIOE_ODR &= (~(0x1<<10));
}
void led2_on()
{
    GPIOF_ODR |= (0x1<<10);
}

void led2_off()
{
    GPIOF_ODR &= (~(0x1<<10));
}
void led3_on()
{
    GPIOE_ODR |= (0x1<<8);
}

void led3_off()
{
    GPIOE_ODR &= (~(0x1<<8));
}

uart4.h

#ifndef __UART4_H__
#define __UART4_H__
#include"stm32mp1xx_rcc.h"
#include"stm32mp1xx_gpio.h"
#include"stm32mp1xx_uart.h"

void uart4_config();
void putchar(char a);
char getchar();
void gets(char *s);
void puts(char *s);
int strcmp(char *s1,char *s2);
#endif

uart4.c

#include"uart4.h"

void uart4_config()
{
    //1.使能GPIOB\GPIOG\UART4外设时钟
    RCC->MP_AHB4ENSETR |= (0x1<<1);//gpiob
    RCC->MP_AHB4ENSETR |= (0x1<<6);//gpiog
    RCC->MP_APB1ENSETR |= (0x1<<16);//uart4
    //2.设置PB2\PG11用于UART4的管脚复用
    //设置PG11
    GPIOG->MODER &= (~(0x3<<22));
    GPIOG->MODER |= (0x2<<22);
    GPIOG->AFRH &= (~(0xf<<12));
    GPIOG->AFRH |= (0x6<<12);
    //设置PB2
    GPIOB->MODER &= (~(0x3<<4));
    GPIOB->MODER |= (0x2<<4);
    GPIOB->AFRL &= (~(0xF<<8));
    GPIOB->AFRL |= (0x8<<8);
    //禁用串口
    USART4->CR1 &= (~0x1);
    //3.设置数据位宽为8位
    USART4->CR1 &= (~(0x1<<12));
    USART4->CR1 &= (~(0x1<<28));
    //4.设置无奇偶校验位
    USART4->CR1 &= (~(0x1<<10));
    //5.设置16倍过采样
    USART4->CR1 &= (~(0x1<<15));
    //6.设置1位停止位
    USART4->CR2 &= (~(0x3<<12));
    //7.设置不分频
    USART4->PRESC &= (~0xf);
    //8.设置波特率为115200
    USART4->BRR=0X22B;
    //9.使能发送器
    USART4->CR1 |= (0x1<<3);
    //10.使能接收器
    USART4->CR1 |= (0x1<<2);
    //11.使能串口
    USART4->CR1 |= (0x1);
}

void putchar(char a)
{
    //1.先判断发送器是否为空，不为空等待
    while(!(USART4->ISR &(0x1<<7)));
    //2.向发送寄存器写入数据
    USART4->TDR=a;
    //3.等待发送完成
    while(!(USART4->ISR &(0x1<<6)));
}

char getchar()
{
    char a;
    //1.判断接收器是否有准备好的数据，没有就等待
    while(!(USART4->ISR &(0x1<<5)));
    //2.读取数据
    a=USART4->RDR;
    //3.返回
    return a;
}
//发送一个字符串
void puts(char *s)
{
    while(*s)
    {
        putchar(*s);
        s++;
    }
    putchar('\r');
    putchar('\n');
}

//接收一个字符串
void gets(char *s)
{
    while(1)
    {
        *s=getchar();
        putchar(*s);//键盘输入的内容在串口上回显
        if(*s=='\r')
            break;
        s++;
    }
    *s='\0';
    putchar('\n');
}

//字符串比较
int strcmp(char *s1,char *s2)
{
    int i = 0;
    while((*(s1+i)) == (*(s2+i))){
        if((*(s1+i)) == '\0'){
            break;
         }
         i++;
    }
    return ((*(s1+i)) - (*(s2+i)));
}

main.c

#include"uart4.h"

#include"led.h"



int main()

{

    char buf[128]; //存储字符串

    char *led1on = "led1on";

    char *led1off = "led1off";

    char *led2on = "led2on";

    char *led2off = "led2off";

    char *led3on = "led3on";

    char *led3off = "led3off";

    uart4_config();//uart4初始化

    all_led_init();//所有灯初始化

    while(1){

        gets(buf);

        puts(buf);

        if(strcmp(buf,led1on) == 0){

            led1_on();

        }else if(strcmp(buf,led2on) == 0){

            led2_on();

        }else if(strcmp(buf,led3on) == 0){

            led3_on();

        }else  if(strcmp(buf,led1off) == 0){

            led1_off();

        }else if(strcmp(buf,led2off) == 0){

            led2_off();

        }else if(strcmp(buf,led3off) == 0){

            led3_off();

        }

    }

}