stm32单片机个人学习笔记13（USART串口协议）

前言

本篇文章属于stm32单片机（以下简称单片机）的学习笔记，来源于B站教学视频。下面是这位up主的视频链接。本文为个人学习笔记，只能做参考，细节方面建议观看视频，肯定受益匪浅。

STM32入门教程-2023版 细致讲解 中文字幕_哔哩哔哩_bilibili

 一、通信接口

二、串口通信

三、电平标准

四、串口参数及时序

五、USART简介 

六、实例一（串口发送）

Serial.c

#include "stm32f10x.h"                  // Device header
#include <stdio.h>


void Serial_Init(void)
{
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 ,ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA ,ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	USART_InitTypeDef USART_InitStructure;
	USART_InitStructure.USART_BaudRate = 9600;
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
	USART_InitStructure.USART_Mode = USART_Mode_Tx;
	USART_InitStructure.USART_Parity = USART_Parity_No;
	USART_InitStructure.USART_StopBits = USART_StopBits_1;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;
	USART_Init(USART1 ,&USART_InitStructure);
	
	USART_Cmd(USART1, ENABLE);
}

void Serial_SendByte(uint8_t Byte)
{
	USART_SendData(USART1, Byte);
	while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);	
}

void Serial_SendArray(uint8_t *Array, uint16_t Length)
{
	uint16_t i;
	for (i = 0;i < Length; i++)
	{
		Serial_SendByte(Array[i]);
	}
}

void Serial_SendString(char *String)
{
	uint8_t i = 0;
	while(String[i] != '\0')
	{
		Serial_SendByte(String[i]);
		i++;
	}		
}
	
uint32_t Serial_Pow(uint32_t X, uint32_t Y)
{
	uint32_t Result = 1;
	while(Y--)
	{
		Result *= X;
	}
	return Result;
}	
	
void Serial_SendNumber(uint32_t Number, uint8_t Length)
{
	uint8_t i;
	for (i = 0;i < Length;i++)
	{
		Serial_SendByte(Number / Serial_Pow(10, Length - i -1) % 10 + '0');
	}
}

 main.c

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Serial.h"

int main(void)
{

	OLED_Init();
	Serial_Init();
	
	Serial_SendByte(0x41);
	
	uint8_t MyArray[] = {0x42,0x43,0x44,0x45};
	
	Serial_SendArray(MyArray, 4);
	Serial_SendString("HelloWorld!\r\n");
	Serial_SendNumber(12345, 5);
	

	while (1)
	{

	}
}

 移植printf函数的方法，有三种

第一种：在Serial.c中加入，注意Serial.c和Serial.h中都要#include <stdio.h>

int fputc(int ch, FILE *f)
{
	Serial_SendByte(ch);
	return ch;
}

然后在main函数中使用即可，这个方法适用于仅一个USART需要使用

第二种：在main函数中使用sprintf

    char String[100];
	sprintf(String,"Num=%d\r\n",777);
	Serial_SendString(String);

第三种：封装sprintf，在Serial.c中加入封装代码

void Serial_Printf(char *format, ...)
{
	char String[100];
	va_list arg;
	va_start(arg,format);
	vsprintf(String, format, arg);
	va_end(arg);
	Serial_SendString(String);
}

然后在main.c中调用

	Serial_Printf("Num=%d\r\n",888);

 七、实例二（串口接收）

Serial.c

#include "stm32f10x.h"                  // Device header
#include <stdio.h>
#include <stdarg.h>

uint8_t Serial_RxData;
uint8_t Serial_RxFlag;

void Serial_Init(void)
{
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 ,ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA ,ENABLE);
	
	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	USART_InitTypeDef USART_InitStructure;
	USART_InitStructure.USART_BaudRate = 9600;
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
	USART_InitStructure.USART_Mode = USART_Mode_Tx | USART_Mode_Rx;
	USART_InitStructure.USART_Parity = USART_Parity_No;
	USART_InitStructure.USART_StopBits = USART_StopBits_1;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;
	USART_Init(USART1 ,&USART_InitStructure);
	
	USART_ITConfig(USART1,USART_IT_RXNE,ENABLE);
	
	NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
	
	NVIC_InitTypeDef NVIC_InitStructure;
	NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_Init(&NVIC_InitStructure);
	USART_Cmd(USART1, ENABLE);
}

void Serial_SendByte(uint8_t Byte)
{
	USART_SendData(USART1, Byte);
	while(USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);	
}

void Serial_SendArray(uint8_t *Array, uint16_t Length)
{
	uint16_t i;
	for (i = 0;i < Length; i++)
	{
		Serial_SendByte(Array[i]);
	}
}

void Serial_SendString(char *String)
{
	uint8_t i = 0;
	while(String[i] != '\0')
	{
		Serial_SendByte(String[i]);
		i++;
	}		
}
	
uint32_t Serial_Pow(uint32_t X, uint32_t Y)
{
	uint32_t Result = 1;
	while(Y--)
	{
		Result *= X;
	}
	return Result;
}	
	
void Serial_SendNumber(uint32_t Number, uint8_t Length)
{
	uint8_t i;
	for (i = 0;i < Length;i++)
	{
		Serial_SendByte(Number / Serial_Pow(10, Length - i -1) % 10 + '0');
	}
}

int fputc(int ch, FILE *f)
{
	Serial_SendByte(ch);
	return ch;
}

void Serial_Printf(char *format, ...)
{
	char String[100];
	va_list arg;
	va_start(arg,format);
	vsprintf(String, format, arg);
	va_end(arg);
	Serial_SendString(String);
}

uint8_t Serial_GetRxFlag()
{
	if (Serial_RxFlag == 1)
	{
		Serial_RxFlag = 0;
		return 1;
	}
	else 
	{
		return 0;
	}
}

uint8_t Serial_GetRxData()
{
	return Serial_RxData;
}

void USART1_IRQHandler(void)
{
	if (USART_GetITStatus(USART1, USART_IT_RXNE)==SET)
	{
		Serial_RxData = USART_ReceiveData(USART1);
		Serial_RxFlag = 1;
		USART_ClearITPendingBit(USART1, USART_IT_RXNE);
	}
}

main.c 

#include "stm32f10x.h"                  // Device header
#include "Delay.h"
#include "OLED.h"
#include "Serial.h"

uint8_t RxData;

int main(void)
{

	OLED_Init();
	Serial_Init();
	OLED_ShowString(1,1,"RxData:");
	
	while (1)
	{
		if (Serial_GetRxFlag() == 1)
		{
			RxData = Serial_GetRxData(USART1);
			Serial_SendByte(RxData);
			OLED_ShowHexNum(1,8,RxData,2);
		}
	}
}