ARMday6

1.串口控制三盏灯亮灭

main.c

#include"uart4.h"
//封装延时函数
void delay(int ms)
{
    int i,j;
    for(i=0;i<ms;i++)
    {
        for(j=0;j<2000;j++)
        {}

    }
}
int main()
{
    //串口初始化
    uart4_init();
    char buf[30];
    while (1)
    {
        gets(buf);
        if (mystrcmp(buf,"LED1_ON"))
        {
            LED1_ON();
        }
        if (mystrcmp(buf,"LED2_ON"))
        {
            LED2_ON();
        }
        if (mystrcmp(buf,"LED3_ON"))
        {
            LED3_ON();
        }
        if (mystrcmp(buf,"LED1_OFF"))
        {
            LED1_OFF();
        }
        if (mystrcmp(buf,"LED2_OFF"))
        {
            LED2_OFF();
        }
        if (mystrcmp(buf,"LED3_OFF"))
        {
            LED3_OFF();
        }
        
        //最终现象，输入a，输出b;
    }
    
    return 0;
}

uart.c

#include "uart4.h"
void uart4_init()
{
    //使能GPIOB GPIOE GPIOF GPIOG UART4 外设时钟
    RCC->MP_AHB4ENSETR |= (0x1<<1);
    RCC->MP_AHB4ENSETR |= (0X3<<4);
    RCC->MP_AHB4ENSETR |= (0x1<<6);
    RCC->MP_APB1ENSETR |= (0x1<<16);
    //设置PB2和PG11管脚复用
    //PB2
    GPIOB->MODER &= (~(0x3)<<4);
    GPIOB->MODER |= (0x2<<4);
    GPIOB->AFRL &= (~(0xF<<8));
    GPIOB->AFRL |= (0x8<<8);    
    //PG11
    GPIOG->MODER &= (~(0x3)<<22);
    GPIOG->MODER |= (0x2<<22);
    GPIOG->AFRL &= (~(0xF<<12));
    GPIOG->AFRL |= (0x6<<12);
    //设置串口不使能 UE=0
    USART4->CR1 &= (~(0x1));
    //设置8位数据位
    USART4->CR1 &= (~(0x1<<12));
    USART4->CR1 &= (~(0x1<<28));
    //设置没有奇偶校验位
    USART4->CR1 &= (~(0x1<<10));
    //设置1位停止位
    USART4->CR2 &= (~(0x3<<12));
    //设置16倍过采样
    USART4->CR1 &= (~(0x1<<15));
    //设置时钟不分频
    USART4->PRESC &= (~(0xF));
    //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uart4
    USART4->CR1 |= (0x1<<0);
    //设置GPIO状态
    //PE10
    GPIOE->MODER &=(~(0x3<<20));
    GPIOE->MODER |=(0x1<<20);
    //PE8
    GPIOE->MODER &=(~(0x3<<16));
    GPIOE->MODER |=(0x1<<16);
    //PF10
    GPIOF->MODER &=(~(0x3<<20));
    GPIOF->MODER |=(0x1<<20);
    //设置输出模式
    GPIOE->OTYPER &=(~(0x1<<10));
    GPIOE->OTYPER &=(~(0x1<<8));
    GPIOF->OTYPER &=(~(0x1<<10));
    //设置引脚速度
    GPIOE->OSPEEDR &=(~(0x1<<20));
    GPIOE->OSPEEDR &=(~(0x1<<16));
    GPIOF->OSPEEDR &=(~(0x1<<20));
    //设置无上拉下拉电阻
    GPIOE->PUPDR &=(~(0x3<<20));
    GPIOE->PUPDR &=(~(0x3<<16));
    GPIOF->PUPDR &=(~(0x3<<20));
    //初始化LED灭灯
    GPIOE->ODR &=(~(0x1<<10));
    GPIOE->ODR &=(~(0x1<<8));
    GPIOF->ODR &=(~(0x1<<10));
}

void putchar(char a)
{
   //先判断发送数据寄存器是否为空
    //不为空等待
   while(!(USART4->ISR&(0x1<<7)));
   //为空写入数据
   USART4->TDR=a;   
   //判断是否写入完成，不完成阻塞等待，完成了则函数结束 
    while(!(USART4->ISR&(0x1<<6)));
}

char getchar()
{
    char a;
    //判断接收数据寄存器是否有数据
    //数据没有准备好则阻塞等待
    while(!(USART4->ISR&(0x1<<5)));
    //准备好则读取
    a=USART4->RDR;
    //读取完毕将读取到的数据返回
    return a;
}
void gets(char *s)
{
    while(1)
    {
        *s=getchar();
        putchar(*s);
        if((*s)=='\r')
            break;
        s++;
    }
    *s='\0';
    putchar('\n');
}
void puts(char *s)
{
    while(1)
    {
        putchar(*s);
        s++;
    }
    putchar('\n');
    putchar('\r');
}
void LED1_ON()
{
    GPIOE->ODR |=(0x1<<10);
}
void LED2_ON()
{
    GPIOF->ODR |=(0x1<<10);
}
void LED3_ON()
{
    GPIOE->ODR |=(0x1<<8);
}
void LED1_OFF()
{
    GPIOE->ODR &=(~(0x1<<10));
}
void LED2_OFF()
{
    GPIOF->ODR &=(~(0x1<<10));
}
void LED3_OFF()
{
    GPIOE->ODR &=(~(0x1<<8));
}
int mystrcmp(char *str,char *dst)
{
    while(*str!='\0')
    {
        if(*str==*dst)
        {
            str++;
            dst++;
            continue;
        }
        break;
    }
    if(*str=='\0')
    {
        return 1;
    }
    return 0;
}

uart.h

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

void uart4_init();
void putchar(char a);
char getchar();
void puts(char *s);
void gets(char *s);
void LED1_ON();
void LED2_ON();
void LED3_ON();
void LED1_OFF();
void LED2_OFF();
void LED3_OFF();
int mystrcmp(char *str,char *dst);
#endif