串口发送控制命令,实现一些外设LED 风扇
uart4.c
#include "uart4.h"
void uart4_config()
{
//1.使能GPIOB\GPIOG\UART4外设时钟
RCC->MP_AHB4ENSETR |= (0x1 << 1);
RCC->MP_AHB4ENSETR |= (0x1 << 6);
RCC->MP_APB1ENSETR |= (0x1 << 16);
//===============================================
//led时钟使能
RCC->MP_AHB4ENSETR |= (0x3 << 4);
//设置PE10输出
GPIOE->MODER &= (~(0x3<<20));
GPIOE->MODER |= (0x1<<20);
//设置PE10为推晚输出
GPIOE->OTYPER &= (~(0x1<<10));
//PE10为低速输出
GPIOE->OSPEEDR &= (~(0x1<<10));
//设置无上拉下拉
GPIOE->PUPDR &= (~(0x3<<20));
//===============================================
//设置PE9输出
GPIOE->MODER &= (~(0x3<<18));
GPIOE->MODER |= (0x1<<18);
//设置PE10为推晚输出
GPIOE->OTYPER &= (~(0x1<<18));
//PE9为低速输出
GPIOE->OSPEEDR &= (~(0x1<<18));
//设置无上拉下拉
GPIOE->PUPDR &= (~(0x3<<18));
//===============================================
//2.设置PB2\PG11用于UART4的管脚复用
//PG11
GPIOG->MODER &= (~(0x3 << 22));
GPIOG->MODER |= (0x2 << 22);
GPIOG->AFRH &= (~(0xf)<<12);
GPIOG->AFRH |= (0x6<<12);
//PB2
GPIOB->MODER &= (~(0x3<<4));
GPIOB->MODER |= (0x2<<4);
GPIOB->AFRL &= (~(0xf)<<8);
GPIOB->AFRL |= (0x1<<11);
//3.0串口禁用
USART4->CR1 &= (~0x1);
//4.设置数据位宽为8位
USART4->CR1 &= (~(0x1<<12));
USART4->CR1 &= (~(0x1<<28));
//5.设置无奇偶校验位
USART4->CR1 &= (~(0x1<<10));
//6.设置16倍过采样
USART4->CR1 &= (~(0x1<<15));
//7.设置1位停止位
USART4->CR2 &= (~(0x3<<12));
//8.设置不分频
USART4->PRESC &= (~0xf);
//9.设置波特率为115200
USART4->BRR = 0x22B;
//10.使能发送器
USART4->CR1 |= (0x1<<3);
//11.使能接收器
USART4->CR1 |= (0x1<<2);
//12.使能串口
USART4->CR1 |= (0x1);
}
void putchar(char a)
{
//1.先判断发生器是否为空
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');
}
int strcmp(char *src,char *dst) //指令比较
{
while(*src != '\0' && *dst != '\0')
{
if(*src != *dst)
{
return *src - *dst;
}
src++;
dst++;
}
if(*src == *dst)
{
return 0;
}
else if(*src == '\0')
{
return *dst;
}
else if(*dst == '\0')
{
return *src;
}
}
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 puts(char *s);
void gets(char *s);
int strcmp(char *src,char *dst);
#endif
main.c
#include"uart4.h"
int main()
{
//char a;
char buf[128];
uart4_config();
while(1)
{
/*
//接收一个字符数据
a = getchar();
//发送 接收的字符+1
putchar(a+1);
putchar('\r');//回车,切换到一行开头
putchar('\n');//切换到下一行
*/
puts("please enter order");
gets(buf);
if(strcmp(buf,"led_on") == 0)
{
GPIOE->ODR |= (0x1<<10);
}
else if(strcmp(buf,"led_off") == 0)
{
GPIOE->ODR &= (~(0x1<<10));
}
else if(strcmp(buf,"fen_on") == 0)
{
GPIOE->ODR |= (0x1<<9);
}
else if(strcmp(buf,"fen_off") == 0)
{
GPIOE->ODR &= (~(0x1<<9));
}
else
{
puts("puts error\n\r");
}
//puts(buf);
}
}
效果演示文章来源:https://www.toymoban.com/news/detail-767759.html
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