[嵌入式]基于IIC协议使用AHT20温湿度传感器进行数据采集

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文章目录

一、I2C总线协议
- 1. I2C总线的物理层
- 2. I2C总线的协议层
- 3. I2C的两种方式——硬件I2C和软件I2C
- - 二.AHT20的采集
- 1.AHT20芯片信息
- 2.stm32f103连接AHT20进行温湿度采集
- 3.代码实现
三、总结
四、参考链接：

一、I2C总线协议

I2C总线是一种双向的同步串行总线，它支持设备之间的短距离通信，经常用于处理器和一些外围设备之间的接口通信。I2C总线的标准通信速率是100Kbps，快速模式是400Kbps，高速模式支持3.4Mbps。I2C总线支持多设备的通信，而且各个设备之间的SCL和SDA线都是线与关系。I2C总线上扩展的器件的数量主要由电容负载来决定，其负载能力为400pF。I2C总线具有极低的电流消耗。

1. I2C总线的物理层

I2C总线物理层由两根线组成：串行时钟线SCL、串行数据线SDA。由于这两根线都是开漏输出结构，因此必须都接上拉电阻到高电平，因此当总线处于空闲状态时，两根线都处于高电平状态。下图为I2C总线的物理层示意图。

在这里插入图片描述

2. I2C总线的协议层

I2C总线上的每一个设备都可以作为主设备或者从设备，而且每一个设备都会对应一个唯一的设备地址。通常的我们将CPU模块作为主设备，而挂接在总线上的其他设备作为从设备。I2C总线上的主设备与从设备之间以8字节为单位进行双向数据传输，并且每个单位后还须跟着一位ACK位。其中数据在SCL处于低电平时被放到SDA数据线上，在SCL处于高电平时进行数据的采样。下图是I2C总线的数据传输协议时序图。

在这里插入图片描述

由图可知，I2C总线的传输时序包括：开始条件、地址帧、数据帧、停止条件、重复开始条件。

开始条件：标识传输正式开始，当SCL处于高电平时，SDA由高电平变为低电平。这样所有Slave设备都会知道传输已经开始。

地址帧：地址帧总是在一次通信的最开始出现，通常包括7位的设备地址(MSB)和最后1位的读写控制位(1表示读，0表示写)。接下来是1位的NACK/ACK，当这8位地址发送完成后，Slave设备获得SDA的控制权，此时Slave设备应该在第9个时钟脉冲之前回复一个ACK(将SDA拉低)以表示数据接收正常，否则表示数据接受失败，控制权交由Master设备处理。

数据帧：在地址帧发送之后，就可以开始传送数据了。每个数据帧8位，数据帧的数量可以是任意的，直到产生停止条件。每一个8位数据传输完成之后，接收方就需要回复一个ACK/NACK。

停止条件：当所有数据都发送完成时，当SCL处于高电平时，SDA由低电平变为高电平。除了开始条件和停止条件，在正常的数据传输过程中，当SCL处于高电平时，SDA上的值不能变化，否则会意外产生停止条件。

重复开始条件：有时Master设备需要在一次通信中进行多次消息交换(例如切换读写操作等)，并且不希望其他Master设备干扰，这时可以使用重复开始条件。再一次通信中，Master设备可以产生多次开始条件来完成多次信息交换，最后在产生一个停止条件结束整个通信过程。

注1：上面都是以8位为一个单元进行的数据传输，其实I2C也是支持10位地址空间的。对于10位地址的传输时序，需要2个地址帧完成地址的传输，其他和8位的传输协议相同。下图为10位地址传输时序图。

在这里插入图片描述

注2：I2C总线的上拉电阻的阻值要精心考虑，如果上拉电阻的阻值太大，则由于I2C设备输入端的输入电容的存在，会造成信号上升沿和下降沿变缓，以至于不能满足I2C设备的建立时间和保持时间，造成通信的错误发生；如果上拉电阻的阻值过小，则会造成较大的功率损耗。因此I2C通信的上拉电阻的阻值要满足设备上升沿和下降沿要求的同时尽量选择较大的阻值，以降低消耗的功耗问题。

3. I2C的两种方式——硬件I2C和软件I2C

①硬件I2C
直接利用 STM32 芯片中的硬件 I²C 外设。

硬件I2C的使用
只要配置好对应的寄存器，外设就会产生标准串口协议的时序。在初始化好 I2C 外设后，只需要把某寄存器位置 1，此时外设就会控制对应的 SCL 及 SDA 线自动产生 I2C 起始信号，不需要内核直接控制引脚的电平。

②软件I2C
直接使用 CPU 内核按照 I2C 协议的要求控制 GPIO 输出高低电平，从而模拟I2C。

软件I2C的使用
需要在控制产生 I2C 的起始信号时，控制作为 SCL 线的 GPIO 引脚输出高电平，然后控制作为 SDA 线的 GPIO 引脚在此期间完成由高电平至低电平的切换，最后再控制SCL 线切换为低电平，这样就输出了一个标准的 I2C 起始信号。

③两者的差别
硬件 I2C 直接使用外设来控制引脚，可以减轻 CPU 的负担。不过使用硬件I2C 时必须使用某些固定的引脚作为 SCL 和 SDA，软件模拟 I2C 则可以使用任意 GPIO 引脚，相对比较灵活。对于硬件I2C用法比较复杂，软件I2C的流程更清楚一些。如果要详细了解I2C的协议，使用软件I2C可能更好的理解这个过程。在使用I2C过程，硬件I2C可能通信更加快，更加稳定。

二.AHT20的采集

1.AHT20芯片信息

下载官方产品介绍文档：http://www.aosong.com/class-36.html

2.stm32f103连接AHT20进行温湿度采集

AHT20	stm32f103
SCL	B6
GND	GND
SDA	B7
VCC	5V

3.代码实现

在固件库的基础上添加代码

main.c

#include "delay.h"
#include "usart.h"
#include "bsp_i2c.h"

int main(void)
{	
	delay_init();     //?óê±oˉêy3?ê??ˉ	  
	uart_init(115200);	 //′??ú3?ê??ˉ?a115200
	IIC_Init();
		while(1)
	{
		printf("温度湿度显示");
		read_AHT20_once();
		delay_ms(1500);
  }
}

usart.c

#include "sys.h"
#include "usart.h"

//STM32F103o?D?°?ày3ì
//?aoˉêy°?±?ày3ì
/********** mcudev.taobao.com 3??·  ********/

// 	 
//è?1?ê1ó?ucos,?ò°üà¨????μ?í·???t?′?é.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h"					//ucos ê1ó?	  
#endif
//	 
//STM32?a·￠°?
//′??ú13?ê??ˉ		   

// 	  
 

//
//?óè?ò???′ú??,?§3?printfoˉêy,??2?Dèòa????use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
//±ê×??aDèòaμ??§3?oˉêy                 
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
//?¨ò?_sys_exit()ò?±ü?aê1ó?°??÷?ú?￡ê?    
void _sys_exit(int x) 
{ 
	x = x; 
} 
//???¨ò?fputcoˉêy 
int fputc(int ch, FILE *f)
{      
	while((USART1->SR&0X40)==0);//?-?··￠?í,?±μ?·￠?ííê±?   
    USART1->DR = (u8) ch;      
	return ch;
}
#endif 

/*ê1ó?microLibμ?·?·¨*/
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   //è?1?ê1?üá??óê?
//′??ú1?D??·t??3ìDò
//×￠òa,?áè?USARTx->SR?ü±ü?a?a??????μ?′í?ó   	
u8 USART_RX_BUF[USART_REC_LEN];     //?óê??o3?,×?′óUSART_REC_LEN??×??ú.
//?óê?×′ì?
//bit15￡?	?óê?íê3é±ê??
//bit14￡?	?óê?μ?0x0d
//bit13~0￡?	?óê?μ?μ?óDD§×??úêy??
u16 USART_RX_STA=0;       //?óê?×′ì?±ê??	  
  
void uart_init(u32 bound){
    //GPIO???úéè??
  GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//ê1?üUSART1￡?GPIOAê±?ó
     //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//?′ó?í?íìê?3?
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????ê?è?
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

   //Usart1 NVIC ????

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?à??ó??è??3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//×óó??è??3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQí¨μàê1?ü
	NVIC_Init(&NVIC_InitStructure);	//?ù?Y???¨μ?2?êy3?ê??ˉVIC??′??÷
  
   //USART 3?ê??ˉéè??

	USART_InitStructure.USART_BaudRate = bound;//ò?°?éè???a9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò???í￡?1??
	USART_InitStructure.USART_Parity = USART_Parity_No;//?T????D￡?é??
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//?Tó2?têy?Yá÷????
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//ê?·￠?￡ê?

    USART_Init(USART1, &USART_InitStructure); //3?ê??ˉ′??ú
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//?a???D??
    USART_Cmd(USART1, ENABLE);                    //ê1?ü′??ú 

}

void USART1_IRQHandler(void)                	//′??ú1?D??·t??3ìDò
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //?óê??D??(?óê?μ?μ?êy?Y±?D?ê?0x0d 0x0a?á?2)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//?áè??óê?μ?μ?êy?Y
		
		if((USART_RX_STA&0x8000)==0)//?óê??′íê3é
			{
			if(USART_RX_STA&0x4000)//?óê?μ?á?0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//?óê?′í?ó,??D??aê?
				else USART_RX_STA|=0x8000;	//?óê?íê3éá? 
				}
			else //?1??ê?μ?0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//?óê?êy?Y′í?ó,??D??aê??óê?	  
					}		 
				}
			}   		 
     } 
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntExit();  											 
#endif
} 
#endif

usart.h

#include "sys.h"
#include "usart.h"

//STM32F103o?D?°?ày3ì
//?aoˉêy°?±?ày3ì
/********** mcudev.taobao.com 3??·  ********/

// 	 
//è?1?ê1ó?ucos,?ò°üà¨????μ?í·???t?′?é.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h"					//ucos ê1ó?	  
#endif
//	 
//STM32?a·￠°?
//′??ú13?ê??ˉ		   

// 	  
 

//
//?óè?ò???′ú??,?§3?printfoˉêy,??2?Dèòa????use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
//±ê×??aDèòaμ??§3?oˉêy                 
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
//?¨ò?_sys_exit()ò?±ü?aê1ó?°??÷?ú?￡ê?    
void _sys_exit(int x) 
{ 
	x = x; 
} 
//???¨ò?fputcoˉêy 
int fputc(int ch, FILE *f)
{      
	while((USART1->SR&0X40)==0);//?-?··￠?í,?±μ?·￠?ííê±?   
    USART1->DR = (u8) ch;      
	return ch;
}
#endif 

/*ê1ó?microLibμ?·?·¨*/
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   //è?1?ê1?üá??óê?
//′??ú1?D??·t??3ìDò
//×￠òa,?áè?USARTx->SR?ü±ü?a?a??????μ?′í?ó   	
u8 USART_RX_BUF[USART_REC_LEN];     //?óê??o3?,×?′óUSART_REC_LEN??×??ú.
//?óê?×′ì?
//bit15￡?	?óê?íê3é±ê??
//bit14￡?	?óê?μ?0x0d
//bit13~0￡?	?óê?μ?μ?óDD§×??úêy??
u16 USART_RX_STA=0;       //?óê?×′ì?±ê??	  
  
void uart_init(u32 bound){
    //GPIO???úéè??
  GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//ê1?üUSART1￡?GPIOAê±?ó
     //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//?′ó?í?íìê?3?
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????ê?è?
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

   //Usart1 NVIC ????

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?à??ó??è??3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//×óó??è??3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQí¨μàê1?ü
	NVIC_Init(&NVIC_InitStructure);	//?ù?Y???¨μ?2?êy3?ê??ˉVIC??′??÷
  
   //USART 3?ê??ˉéè??

	USART_InitStructure.USART_BaudRate = bound;//ò?°?éè???a9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò???í￡?1??
	USART_InitStructure.USART_Parity = USART_Parity_No;//?T????D￡?é??
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//?Tó2?têy?Yá÷????
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//ê?·￠?￡ê?

    USART_Init(USART1, &USART_InitStructure); //3?ê??ˉ′??ú
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//?a???D??
    USART_Cmd(USART1, ENABLE);                    //ê1?ü′??ú 

}

void USART1_IRQHandler(void)                	//′??ú1?D??·t??3ìDò
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //?óê??D??(?óê?μ?μ?êy?Y±?D?ê?0x0d 0x0a?á?2)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//?áè??óê?μ?μ?êy?Y
		
		if((USART_RX_STA&0x8000)==0)//?óê??′íê3é
			{
			if(USART_RX_STA&0x4000)//?óê?μ?á?0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//?óê?′í?ó,??D??aê?
				else USART_RX_STA|=0x8000;	//?óê?íê3éá? 
				}
			else //?1??ê?μ?0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//?óê?êy?Y′í?ó,??D??aê??óê?	  
					}		 
				}
			}   		 
     } 
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntExit();  											 
#endif
} 
#endif

bsp_i2c.c

#include "sys.h"
#include "usart.h"

//STM32F103o?D?°?ày3ì
//?aoˉêy°?±?ày3ì
/********** mcudev.taobao.com 3??·  ********/

// 	 
//è?1?ê1ó?ucos,?ò°üà¨????μ?í·???t?′?é.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h"					//ucos ê1ó?	  
#endif
//	 
//STM32?a·￠°?
//′??ú13?ê??ˉ		   

// 	  
 

//
//?óè?ò???′ú??,?§3?printfoˉêy,??2?Dèòa????use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
//±ê×??aDèòaμ??§3?oˉêy                 
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
//?¨ò?_sys_exit()ò?±ü?aê1ó?°??÷?ú?￡ê?    
void _sys_exit(int x) 
{ 
	x = x; 
} 
//???¨ò?fputcoˉêy 
int fputc(int ch, FILE *f)
{      
	while((USART1->SR&0X40)==0);//?-?··￠?í,?±μ?·￠?ííê±?   
    USART1->DR = (u8) ch;      
	return ch;
}
#endif 

/*ê1ó?microLibμ?·?·¨*/
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   //è?1?ê1?üá??óê?
//′??ú1?D??·t??3ìDò
//×￠òa,?áè?USARTx->SR?ü±ü?a?a??????μ?′í?ó   	
u8 USART_RX_BUF[USART_REC_LEN];     //?óê??o3?,×?′óUSART_REC_LEN??×??ú.
//?óê?×′ì?
//bit15￡?	?óê?íê3é±ê??
//bit14￡?	?óê?μ?0x0d
//bit13~0￡?	?óê?μ?μ?óDD§×??úêy??
u16 USART_RX_STA=0;       //?óê?×′ì?±ê??	  
  
void uart_init(u32 bound){
    //GPIO???úéè??
  GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//ê1?üUSART1￡?GPIOAê±?ó
     //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//?′ó?í?íìê?3?
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????ê?è?
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

   //Usart1 NVIC ????

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?à??ó??è??3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//×óó??è??3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQí¨μàê1?ü
	NVIC_Init(&NVIC_InitStructure);	//?ù?Y???¨μ?2?êy3?ê??ˉVIC??′??÷
  
   //USART 3?ê??ˉéè??

	USART_InitStructure.USART_BaudRate = bound;//ò?°?éè???a9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò???í￡?1??
	USART_InitStructure.USART_Parity = USART_Parity_No;//?T????D￡?é??
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//?Tó2?têy?Yá÷????
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//ê?·￠?￡ê?

    USART_Init(USART1, &USART_InitStructure); //3?ê??ˉ′??ú
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//?a???D??
    USART_Cmd(USART1, ENABLE);                    //ê1?ü′??ú 

}

void USART1_IRQHandler(void)                	//′??ú1?D??·t??3ìDò
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //?óê??D??(?óê?μ?μ?êy?Y±?D?ê?0x0d 0x0a?á?2)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//?áè??óê?μ?μ?êy?Y
		
		if((USART_RX_STA&0x8000)==0)//?óê??′íê3é
			{
			if(USART_RX_STA&0x4000)//?óê?μ?á?0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//?óê?′í?ó,??D??aê?
				else USART_RX_STA|=0x8000;	//?óê?íê3éá? 
				}
			else //?1??ê?μ?0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//?óê?êy?Y′í?ó,??D??aê??óê?	  
					}		 
				}
			}   		 
     } 
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntExit();  											 
#endif
} 
#endif

bsp_i2c.h

#include "sys.h"
#include "usart.h"

//STM32F103o?D?°?ày3ì
//?aoˉêy°?±?ày3ì
/********** mcudev.taobao.com 3??·  ********/

// 	 
//è?1?ê1ó?ucos,?ò°üà¨????μ?í·???t?′?é.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h"					//ucos ê1ó?	  
#endif
//	 
//STM32?a·￠°?
//′??ú13?ê??ˉ		   

// 	  
 

//
//?óè?ò???′ú??,?§3?printfoˉêy,??2?Dèòa????use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
//±ê×??aDèòaμ??§3?oˉêy                 
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
//?¨ò?_sys_exit()ò?±ü?aê1ó?°??÷?ú?￡ê?    
void _sys_exit(int x) 
{ 
	x = x; 
} 
//???¨ò?fputcoˉêy 
int fputc(int ch, FILE *f)
{      
	while((USART1->SR&0X40)==0);//?-?··￠?í,?±μ?·￠?ííê±?   
    USART1->DR = (u8) ch;      
	return ch;
}
#endif 

/*ê1ó?microLibμ?·?·¨*/
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   //è?1?ê1?üá??óê?
//′??ú1?D??·t??3ìDò
//×￠òa,?áè?USARTx->SR?ü±ü?a?a??????μ?′í?ó   	
u8 USART_RX_BUF[USART_REC_LEN];     //?óê??o3?,×?′óUSART_REC_LEN??×??ú.
//?óê?×′ì?
//bit15￡?	?óê?íê3é±ê??
//bit14￡?	?óê?μ?0x0d
//bit13~0￡?	?óê?μ?μ?óDD§×??úêy??
u16 USART_RX_STA=0;       //?óê?×′ì?±ê??	  
  
void uart_init(u32 bound){
    //GPIO???úéè??
  GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//ê1?üUSART1￡?GPIOAê±?ó
     //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//?′ó?í?íìê?3?
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????ê?è?
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

   //Usart1 NVIC ????

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?à??ó??è??3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//×óó??è??3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQí¨μàê1?ü
	NVIC_Init(&NVIC_InitStructure);	//?ù?Y???¨μ?2?êy3?ê??ˉVIC??′??÷
  
   //USART 3?ê??ˉéè??

	USART_InitStructure.USART_BaudRate = bound;//ò?°?éè???a9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò???í￡?1??
	USART_InitStructure.USART_Parity = USART_Parity_No;//?T????D￡?é??
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//?Tó2?têy?Yá÷????
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//ê?·￠?￡ê?

    USART_Init(USART1, &USART_InitStructure); //3?ê??ˉ′??ú
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//?a???D??
    USART_Cmd(USART1, ENABLE);                    //ê1?ü′??ú 

}

void USART1_IRQHandler(void)                	//′??ú1?D??·t??3ìDò
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //?óê??D??(?óê?μ?μ?êy?Y±?D?ê?0x0d 0x0a?á?2)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//?áè??óê?μ?μ?êy?Y
		
		if((USART_RX_STA&0x8000)==0)//?óê??′íê3é
			{
			if(USART_RX_STA&0x4000)//?óê?μ?á?0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//?óê?′í?ó,??D??aê?
				else USART_RX_STA|=0x8000;	//?óê?íê3éá? 
				}
			else //?1??ê?μ?0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//?óê?êy?Y′í?ó,??D??aê??óê?	  
					}		 
				}
			}   		 
     } 
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntExit();  											 
#endif
} 
#endif

delay.c

#include "sys.h"
#include "usart.h"

//STM32F103o?D?°?ày3ì
//?aoˉêy°?±?ày3ì
/********** mcudev.taobao.com 3??·  ********/

// 	 
//è?1?ê1ó?ucos,?ò°üà¨????μ?í·???t?′?é.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h"					//ucos ê1ó?	  
#endif
//	 
//STM32?a·￠°?
//′??ú13?ê??ˉ		   

// 	  
 

//
//?óè?ò???′ú??,?§3?printfoˉêy,??2?Dèòa????use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
//±ê×??aDèòaμ??§3?oˉêy                 
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
//?¨ò?_sys_exit()ò?±ü?aê1ó?°??÷?ú?￡ê?    
void _sys_exit(int x) 
{ 
	x = x; 
} 
//???¨ò?fputcoˉêy 
int fputc(int ch, FILE *f)
{      
	while((USART1->SR&0X40)==0);//?-?··￠?í,?±μ?·￠?ííê±?   
    USART1->DR = (u8) ch;      
	return ch;
}
#endif 

/*ê1ó?microLibμ?·?·¨*/
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   //è?1?ê1?üá??óê?
//′??ú1?D??·t??3ìDò
//×￠òa,?áè?USARTx->SR?ü±ü?a?a??????μ?′í?ó   	
u8 USART_RX_BUF[USART_REC_LEN];     //?óê??o3?,×?′óUSART_REC_LEN??×??ú.
//?óê?×′ì?
//bit15￡?	?óê?íê3é±ê??
//bit14￡?	?óê?μ?0x0d
//bit13~0￡?	?óê?μ?μ?óDD§×??úêy??
u16 USART_RX_STA=0;       //?óê?×′ì?±ê??	  
  
void uart_init(u32 bound){
    //GPIO???úéè??
  GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//ê1?üUSART1￡?GPIOAê±?ó
     //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//?′ó?í?íìê?3?
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????ê?è?
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

   //Usart1 NVIC ????

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?à??ó??è??3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//×óó??è??3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQí¨μàê1?ü
	NVIC_Init(&NVIC_InitStructure);	//?ù?Y???¨μ?2?êy3?ê??ˉVIC??′??÷
  
   //USART 3?ê??ˉéè??

	USART_InitStructure.USART_BaudRate = bound;//ò?°?éè???a9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò???í￡?1??
	USART_InitStructure.USART_Parity = USART_Parity_No;//?T????D￡?é??
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//?Tó2?têy?Yá÷????
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//ê?·￠?￡ê?

    USART_Init(USART1, &USART_InitStructure); //3?ê??ˉ′??ú
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//?a???D??
    USART_Cmd(USART1, ENABLE);                    //ê1?ü′??ú 

}

void USART1_IRQHandler(void)                	//′??ú1?D??·t??3ìDò
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //?óê??D??(?óê?μ?μ?êy?Y±?D?ê?0x0d 0x0a?á?2)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//?áè??óê?μ?μ?êy?Y
		
		if((USART_RX_STA&0x8000)==0)//?óê??′íê3é
			{
			if(USART_RX_STA&0x4000)//?óê?μ?á?0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//?óê?′í?ó,??D??aê?
				else USART_RX_STA|=0x8000;	//?óê?íê3éá? 
				}
			else //?1??ê?μ?0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//?óê?êy?Y′í?ó,??D??aê??óê?	  
					}		 
				}
			}   		 
     } 
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntExit();  											 
#endif
} 
#endif

delay.h

#include "sys.h"
#include "usart.h"

//STM32F103o?D?°?ày3ì
//?aoˉêy°?±?ày3ì
/********** mcudev.taobao.com 3??·  ********/

// 	 
//è?1?ê1ó?ucos,?ò°üà¨????μ?í·???t?′?é.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h"					//ucos ê1ó?	  
#endif
//	 
//STM32?a·￠°?
//′??ú13?ê??ˉ		   

// 	  
 

//
//?óè?ò???′ú??,?§3?printfoˉêy,??2?Dèòa????use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
//±ê×??aDèòaμ??§3?oˉêy                 
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
//?¨ò?_sys_exit()ò?±ü?aê1ó?°??÷?ú?￡ê?    
void _sys_exit(int x) 
{ 
	x = x; 
} 
//???¨ò?fputcoˉêy 
int fputc(int ch, FILE *f)
{      
	while((USART1->SR&0X40)==0);//?-?··￠?í,?±μ?·￠?ííê±?   
    USART1->DR = (u8) ch;      
	return ch;
}
#endif 

/*ê1ó?microLibμ?·?·¨*/
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   //è?1?ê1?üá??óê?
//′??ú1?D??·t??3ìDò
//×￠òa,?áè?USARTx->SR?ü±ü?a?a??????μ?′í?ó   	
u8 USART_RX_BUF[USART_REC_LEN];     //?óê??o3?,×?′óUSART_REC_LEN??×??ú.
//?óê?×′ì?
//bit15￡?	?óê?íê3é±ê??
//bit14￡?	?óê?μ?0x0d
//bit13~0￡?	?óê?μ?μ?óDD§×??úêy??
u16 USART_RX_STA=0;       //?óê?×′ì?±ê??	  
  
void uart_init(u32 bound){
    //GPIO???úéè??
  GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//ê1?üUSART1￡?GPIOAê±?ó
     //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//?′ó?í?íìê?3?
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????ê?è?
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

   //Usart1 NVIC ????

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?à??ó??è??3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//×óó??è??3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQí¨μàê1?ü
	NVIC_Init(&NVIC_InitStructure);	//?ù?Y???¨μ?2?êy3?ê??ˉVIC??′??÷
  
   //USART 3?ê??ˉéè??

	USART_InitStructure.USART_BaudRate = bound;//ò?°?éè???a9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò???í￡?1??
	USART_InitStructure.USART_Parity = USART_Parity_No;//?T????D￡?é??
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//?Tó2?têy?Yá÷????
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//ê?·￠?￡ê?

    USART_Init(USART1, &USART_InitStructure); //3?ê??ˉ′??ú
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//?a???D??
    USART_Cmd(USART1, ENABLE);                    //ê1?ü′??ú 

}

void USART1_IRQHandler(void)                	//′??ú1?D??·t??3ìDò
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //?óê??D??(?óê?μ?μ?êy?Y±?D?ê?0x0d 0x0a?á?2)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//?áè??óê?μ?μ?êy?Y
		
		if((USART_RX_STA&0x8000)==0)//?óê??′íê3é
			{
			if(USART_RX_STA&0x4000)//?óê?μ?á?0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//?óê?′í?ó,??D??aê?
				else USART_RX_STA|=0x8000;	//?óê?íê3éá? 
				}
			else //?1??ê?μ?0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//?óê?êy?Y′í?ó,??D??aê??óê?	  
					}		 
				}
			}   		 
     } 
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntExit();  											 
#endif
} 
#endif

sys.c

#include "sys.h"
#include "usart.h"

//STM32F103o?D?°?ày3ì
//?aoˉêy°?±?ày3ì
/********** mcudev.taobao.com 3??·  ********/

// 	 
//è?1?ê1ó?ucos,?ò°üà¨????μ?í·???t?′?é.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h"					//ucos ê1ó?	  
#endif
//	 
//STM32?a·￠°?
//′??ú13?ê??ˉ		   

// 	  
 

//
//?óè?ò???′ú??,?§3?printfoˉêy,??2?Dèòa????use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
//±ê×??aDèòaμ??§3?oˉêy                 
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
//?¨ò?_sys_exit()ò?±ü?aê1ó?°??÷?ú?￡ê?    
void _sys_exit(int x) 
{ 
	x = x; 
} 
//???¨ò?fputcoˉêy 
int fputc(int ch, FILE *f)
{      
	while((USART1->SR&0X40)==0);//?-?··￠?í,?±μ?·￠?ííê±?   
    USART1->DR = (u8) ch;      
	return ch;
}
#endif 

/*ê1ó?microLibμ?·?·¨*/
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   //è?1?ê1?üá??óê?
//′??ú1?D??·t??3ìDò
//×￠òa,?áè?USARTx->SR?ü±ü?a?a??????μ?′í?ó   	
u8 USART_RX_BUF[USART_REC_LEN];     //?óê??o3?,×?′óUSART_REC_LEN??×??ú.
//?óê?×′ì?
//bit15￡?	?óê?íê3é±ê??
//bit14￡?	?óê?μ?0x0d
//bit13~0￡?	?óê?μ?μ?óDD§×??úêy??
u16 USART_RX_STA=0;       //?óê?×′ì?±ê??	  
  
void uart_init(u32 bound){
    //GPIO???úéè??
  GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//ê1?üUSART1￡?GPIOAê±?ó
     //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//?′ó?í?íìê?3?
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????ê?è?
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

   //Usart1 NVIC ????

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?à??ó??è??3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//×óó??è??3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQí¨μàê1?ü
	NVIC_Init(&NVIC_InitStructure);	//?ù?Y???¨μ?2?êy3?ê??ˉVIC??′??÷
  
   //USART 3?ê??ˉéè??

	USART_InitStructure.USART_BaudRate = bound;//ò?°?éè???a9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò???í￡?1??
	USART_InitStructure.USART_Parity = USART_Parity_No;//?T????D￡?é??
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//?Tó2?têy?Yá÷????
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//ê?·￠?￡ê?

    USART_Init(USART1, &USART_InitStructure); //3?ê??ˉ′??ú
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//?a???D??
    USART_Cmd(USART1, ENABLE);                    //ê1?ü′??ú 

}

void USART1_IRQHandler(void)                	//′??ú1?D??·t??3ìDò
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //?óê??D??(?óê?μ?μ?êy?Y±?D?ê?0x0d 0x0a?á?2)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//?áè??óê?μ?μ?êy?Y
		
		if((USART_RX_STA&0x8000)==0)//?óê??′íê3é
			{
			if(USART_RX_STA&0x4000)//?óê?μ?á?0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//?óê?′í?ó,??D??aê?
				else USART_RX_STA|=0x8000;	//?óê?íê3éá? 
				}
			else //?1??ê?μ?0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//?óê?êy?Y′í?ó,??D??aê??óê?	  
					}		 
				}
			}   		 
     } 
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntExit();  											 
#endif
} 
#endif

sys.h

#include "sys.h"
#include "usart.h"

//STM32F103o?D?°?ày3ì
//?aoˉêy°?±?ày3ì
/********** mcudev.taobao.com 3??·  ********/

// 	 
//è?1?ê1ó?ucos,?ò°üà¨????μ?í·???t?′?é.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h"					//ucos ê1ó?	  
#endif
//	 
//STM32?a·￠°?
//′??ú13?ê??ˉ		   

// 	  
 

//
//?óè?ò???′ú??,?§3?printfoˉêy,??2?Dèòa????use MicroLIB	  
#if 1
#pragma import(__use_no_semihosting)             
//±ê×??aDèòaμ??§3?oˉêy                 
struct __FILE 
{ 
	int handle; 

}; 

FILE __stdout;       
//?¨ò?_sys_exit()ò?±ü?aê1ó?°??÷?ú?￡ê?    
void _sys_exit(int x) 
{ 
	x = x; 
} 
//???¨ò?fputcoˉêy 
int fputc(int ch, FILE *f)
{      
	while((USART1->SR&0X40)==0);//?-?··￠?í,?±μ?·￠?ííê±?   
    USART1->DR = (u8) ch;      
	return ch;
}
#endif 

/*ê1ó?microLibμ?·?·¨*/
 /* 
int fputc(int ch, FILE *f)
{
	USART_SendData(USART1, (uint8_t) ch);

	while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}	
   
    return ch;
}
int GetKey (void)  { 

    while (!(USART1->SR & USART_FLAG_RXNE));

    return ((int)(USART1->DR & 0x1FF));
}
*/
 
#if EN_USART1_RX   //è?1?ê1?üá??óê?
//′??ú1?D??·t??3ìDò
//×￠òa,?áè?USARTx->SR?ü±ü?a?a??????μ?′í?ó   	
u8 USART_RX_BUF[USART_REC_LEN];     //?óê??o3?,×?′óUSART_REC_LEN??×??ú.
//?óê?×′ì?
//bit15￡?	?óê?íê3é±ê??
//bit14￡?	?óê?μ?0x0d
//bit13~0￡?	?óê?μ?μ?óDD§×??úêy??
u16 USART_RX_STA=0;       //?óê?×′ì?±ê??	  
  
void uart_init(u32 bound){
    //GPIO???úéè??
  GPIO_InitTypeDef GPIO_InitStructure;
	USART_InitTypeDef USART_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	 
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);	//ê1?üUSART1￡?GPIOAê±?ó
     //USART1_TX   PA.9
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;	//?′ó?í?íìê?3?
    GPIO_Init(GPIOA, &GPIO_InitStructure);
   
    //USART1_RX	  PA.10
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//????ê?è?
    GPIO_Init(GPIOA, &GPIO_InitStructure);  

   //Usart1 NVIC ????

    NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//?à??ó??è??3
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;		//×óó??è??3
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;			//IRQí¨μàê1?ü
	NVIC_Init(&NVIC_InitStructure);	//?ù?Y???¨μ?2?êy3?ê??ˉVIC??′??÷
  
   //USART 3?ê??ˉéè??

	USART_InitStructure.USART_BaudRate = bound;//ò?°?éè???a9600;
	USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×?3¤?a8??êy?Y??ê?
	USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò???í￡?1??
	USART_InitStructure.USART_Parity = USART_Parity_No;//?T????D￡?é??
	USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//?Tó2?têy?Yá÷????
	USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;	//ê?·￠?￡ê?

    USART_Init(USART1, &USART_InitStructure); //3?ê??ˉ′??ú
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//?a???D??
    USART_Cmd(USART1, ENABLE);                    //ê1?ü′??ú 

}

void USART1_IRQHandler(void)                	//′??ú1?D??·t??3ìDò
	{
	u8 Res;
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntEnter();    
#endif
	if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //?óê??D??(?óê?μ?μ?êy?Y±?D?ê?0x0d 0x0a?á?2)
		{
		Res =USART_ReceiveData(USART1);//(USART1->DR);	//?áè??óê?μ?μ?êy?Y
		
		if((USART_RX_STA&0x8000)==0)//?óê??′íê3é
			{
			if(USART_RX_STA&0x4000)//?óê?μ?á?0x0d
				{
				if(Res!=0x0a)USART_RX_STA=0;//?óê?′í?ó,??D??aê?
				else USART_RX_STA|=0x8000;	//?óê?íê3éá? 
				}
			else //?1??ê?μ?0X0D
				{	
				if(Res==0x0d)USART_RX_STA|=0x4000;
				else
					{
					USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
					USART_RX_STA++;
					if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//?óê?êy?Y′í?ó,??D??aê??óê?	  
					}		 
				}
			}   		 
     } 
#ifdef OS_TICKS_PER_SEC	 	//è?1?ê±?ó?ú??êy?¨ò?á?,?μ?÷òaê1ó?ucosIIá?.
	OSIntExit();  											 
#endif
} 
#endif

将上述文件放在项目的USER文件夹下

编译生成HEX文件，利用串口下载程序将代码烧录到STM32芯片上，打开串口调试助手，打开串口

效果如下：

在这里插入图片描述

用手捏住芯片，可以观察到温度升高。

三、总结

I2C总线只需要两根线就能驱动多个设备，在同样符合该协议的设备上移植性较好，但传输速率较慢，要实现双向通讯，还需要额外增加通信口线。

四、参考链接：

https://blog.csdn.net/weixin_40877615/article/details/94338850

https://blog.csdn.net/qq_43279579/article/details/111597278

这篇关于[嵌入式]基于IIC协议使用AHT20温湿度传感器进行数据采集的文章就介绍到这儿，希望我们推荐的文章对大家有所帮助，也希望大家多多支持为之网！

C/C++教程

[嵌入式]基于IIC协议使用AHT20温湿度传感器进行数据采集

文章目录

一、I2C总线协议

1. I2C总线的物理层

2. I2C总线的协议层

3. I2C的两种方式——硬件I2C和软件I2C

二.AHT20的采集

1.AHT20芯片信息

2.stm32f103连接AHT20进行温湿度采集

3.代码实现

三、总结

四、参考链接：

前端开发

后端开发

移动端开发

数据库

服务器运维

人工智能

区块链

游戏开发

网站运营

大数据/云计算

软件工程

软件/开发工具使用

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