2022.12.27---UART

原创已于 2022-12-28 15:13:26 修改 · 92 阅读

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#单片机 #stm32 #嵌入式硬件

于 2022-12-27 21:00:37 首次发布

本文介绍STM32微控制器中UART4模块的初始化配置及数据收发功能实现。通过具体的C语言代码示例，展示了如何设置引脚、波特率及寄存器等，实现了字符与字符串的发送和接收。

实现串口的数据收发

#include "uart4.h"


//uart4初始化
void hal_uart4_init()
{
	RCC->MP_AHB4ENSETR |= (0x1<<1);
	RCC->MP_AHB4ENSETR |= (0x1<<6);
	RCC->MP_APB1ENSETR |= (0x1<<16);
	//PB2设置为复用功能
	GPIOB->MODER &= (~(0X3<<4));
	GPIOB->MODER |= (0X2<<4);
	GPIOB->AFRL &= (~(0XF<<8));
	GPIOB->AFRL |= (0X8<<8);

	//PG11设置为复用功能
	GPIOG->MODER &= (~(0X3<<22));
	GPIOG->MODER |= (0X2<<22);
	GPIOG->AFRH &= (~(0XF<<12));
	GPIOG->AFRH |= (0X6<<12);

	//设置CR1
	USART4->CR1 &= (~(0x1 << 28));
	USART4->CR1 &= (~(0x1 << 12));
	USART4->CR1 &= (~(0x1 << 10));
	USART4->CR1 &= (~(0x1 << 15));
	
	//设置CR2
	USART4->CR2 &= (~(0x3 << 12));

	//设置PRESC
	USART4->PRESC &= (~(0xF << 0));

	//设置BRR
	USART4->BRR |= 0x22b;

	USART4->CR1 |= (0x1 << 3);
	USART4->CR1 |= (0x1 << 2);
	USART4->CR1 |= (0x1 << 0);
}

//发送一个字符
void put_char(const char ch)
{
	while(!(USART4->ISR & (0x1 << 7)));
	USART4->TDR = ch;
	while(!(USART4->ISR & (0x1 << 6)));
}

//发送一个字符串
void put_string(const char *str)
{
	while(*str)
	{
		put_char(*str++);
	}
	put_char('\n');
	put_char('\r');
}

//接收一个字符
char get_char()
{
	char ch=0;
	while(!(USART4->ISR & (0x1 << 5)));
	ch = USART4->RDR;//2.接收到数据
	return ch;
}

//接收一个字符串
char str[16]="";
char *get_string()
{
	int i=0;
	for(i=0;i<16;i++)
	{
		str[i] = get_char(); //接收一个字符
		put_char(str[i]); //发送一个字符 
		if(str[i] == '\r') //判断键盘enter键是否按下
			break;
	}
	str[i] = '\0';
	put_char('\n');
	return str;
}