嵌入式作业stm32通过I2C接口实现温湿度采集
目录
前言
一.I2C的介绍
1.I2C简介
2.I2C硬件简介
3. I2C软件简介
4两者区别
二.程序实现
1.连接硬件
2.代码实现
3.烧录
4.结果
三.总结
四.参考资料
stm32通过I2C接口实现温湿度（AHT20）的采集
前言
软件版本: KEIl:5.61
mcuisp
firefools
硬件: STM32F103C8T
AHT20温湿度传感器
任务：每隔2秒钟采集一次温湿度数据，并通过串口发送到上位机
一.I2C的介绍
1.I2C简介
I2C总线是由Philips公司开发的一种简单、双向二线制同步串行总线。它只需要两根线即可在连接于总线上的器件之间传送信息。
主器件用于启动总线传送数据，并产生时钟以开放传送的器件，此时任何被寻址的器件均被认为是从器件．在总线上主和从、发和收的关系不是恒定的，而取决于此时数据传送方向。如果主机要发送数据给从器件，则主机首先寻址从器件，然后主动发送数据至从器件，最后由主机终止数据传送；如果主机要接收从器件的数据，首先由主器件寻址从器件．然后主机接收从器件发送的数据，最后由主机终止接收过程。在这种情况下．主机负责产生定时时钟和终止数据传送。
2.I2C硬件简介
定义：直接利用 STM32 芯片中的硬件 I2C 外设
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。
I2C仅需两根线就可以支持一主多从或者多主连接，I2C使用两个双向开漏线，一条双向串行数据线(SDA) ，一条串行时钟线(SCL)，配合上拉电阻进行连接，关于上拉电阻阻值大小有最大值和最小值的限制。
- SDA:串行数据线
- SCL:串行时钟线
3. I2C软件简介
定义：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。
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。
4两者区别
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.程序实现
1.连接硬件
AHT20的SCL，GND，SDA，VCC分别对应接stm32f103指南者i2c模块的B6，GND，B7，5V
2.代码实现
此处在固件库版的空白工程上进行添加代码
首先主函数如下：
main.c
#include "delay.h"
#include "usart.h"
#include "bsp_i2c.h"
int main(void)
{
delay_init(); //ÑÓʱº¯Êý³õʼ»¯
uart_init(115200); //´®¿Ú³õʼ»¯Îª115200
IIC_Init();
while(1)
{
printf("¿ªÊ¼²âÁ¿£¬ÇëÉԵȣº");
read_AHT20_once();
delay_ms(1500);
}
}然后把以下代码文件和main.c放到一起
usart.c
#include "sys.h"
#include "usart.h"
//STM32F103ºËÐÄ°åÀý³Ì
//¿âº¯Êý°æ±¾Àý³Ì
/********** mcudev.taobao.com ³öÆ· ********/
//
//Èç¹ûʹÓÃucos,Ôò°üÀ¨ÏÂÃæµÄÍ·Îļþ¼´¿É.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h" //ucos ʹÓÃ
#endif
//
//STM32¿ª·¢°å
//´®¿Ú1³õʼ»¯
//
//
//¼ÓÈëÒÔÏ´úÂë,Ö§³Öprintfº¯Êý,¶ø²»ÐèҪѡÔñuse MicroLIB
#if 1
#pragma import(__use_no_semihosting)
//±ê×¼¿âÐèÒªµÄÖ§³Öº¯Êý
struct __FILE
{
int handle;
};
FILE __stdout;
//¶¨Òå_sys_exit()ÒÔ±ÜÃâʹÓðëÖ÷»úģʽ
void _sys_exit(int x)
{
x = x;
}
//Öض¨Òåfputcº¯Êý
int fputc(int ch, FILE *f)
{
while((USART1->SR&0X40)==0);//Ñ»··¢ËÍ,Ö±µ½·¢ËÍÍê±Ï
USART1->DR = (u8) ch;
return ch;
}
#endif
/*ʹÓÃmicroLibµÄ·½·¨*/
/*
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 //Èç¹ûʹÄÜÁ˽ÓÊÕ
//´®¿Ú1ÖжϷþÎñ³ÌÐò
//×¢Òâ,¶ÁÈ¡USARTx->SRÄܱÜÃâĪÃûÆäÃîµÄ´íÎó
u8 USART_RX_BUF[USART_REC_LEN]; //½ÓÊÕ»º³å,×î´óUSART_REC_LEN¸ö×Ö½Ú.
//½ÓÊÕ״̬
//bit15£¬ ½ÓÊÕÍê³É±êÖ¾
//bit14£¬ ½ÓÊÕµ½0x0d
//bit13~0£¬ ½ÓÊÕµ½µÄÓÐЧ×Ö½ÚÊýÄ¿
u16 USART_RX_STA=0; //½ÓÊÕ״̬±ê¼Ç
void uart_init(u32 bound){
//GPIO¶Ë¿ÚÉèÖÃ
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE); //ʹÄÜUSART1£¬GPIOAʱÖÓ
//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; //¸´ÓÃÍÆÍìÊä³ö
GPIO_Init(GPIOA, &GPIO_InitStructure);
//USART1_RX PA.10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//¸¡¿ÕÊäÈë
GPIO_Init(GPIOA, &GPIO_InitStructure);
//Usart1 NVIC ÅäÖÃ
NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//ÇÀÕ¼ÓÅÏȼ¶3
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //×ÓÓÅÏȼ¶3
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQͨµÀʹÄÜ
NVIC_Init(&NVIC_InitStructure); //¸ù¾ÝÖ¸¶¨µÄ²ÎÊý³õʼ»¯VIC¼Ä´æÆ÷
//USART ³õʼ»¯ÉèÖÃ
USART_InitStructure.USART_BaudRate = bound;//Ò»°ãÉèÖÃΪ9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×Ö³¤Îª8λÊý¾Ý¸ñʽ
USART_InitStructure.USART_StopBits = USART_StopBits_1;//Ò»¸öֹͣλ
USART_InitStructure.USART_Parity = USART_Parity_No;//ÎÞÆæżУÑéλ
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//ÎÞÓ²¼þÊý¾ÝÁ÷¿ØÖÆ
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx; //ÊÕ·¢Ä£Ê½
USART_Init(USART1, &USART_InitStructure); //³õʼ»¯´®¿Ú
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//¿ªÆôÖжÏ
USART_Cmd(USART1, ENABLE); //ʹÄÜ´®¿Ú
}
void USART1_IRQHandler(void) //´®¿Ú1ÖжϷþÎñ³ÌÐò
{
u8 Res;
#ifdef OS_TICKS_PER_SEC //Èç¹ûʱÖÓ½ÚÅÄÊý¶¨ÒåÁË,˵Ã÷ҪʹÓÃucosIIÁË.
OSIntEnter();
#endif
if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET) //½ÓÊÕÖжÏ(½ÓÊÕµ½µÄÊý¾Ý±ØÐëÊÇ0x0d 0x0a½áβ)
{
Res =USART_ReceiveData(USART1);//(USART1->DR); //¶ÁÈ¡½ÓÊÕµ½µÄÊý¾Ý
if((USART_RX_STA&0x8000)==0)//½ÓÊÕδÍê³É
{
if(USART_RX_STA&0x4000)//½ÓÊÕµ½ÁË0x0d
{
if(Res!=0x0a)USART_RX_STA=0;//½ÓÊÕ´íÎó,ÖØпªÊ¼
else USART_RX_STA|=0x8000; //½ÓÊÕÍê³ÉÁË
}
else //»¹Ã»ÊÕµ½0X0D
{
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;//½ÓÊÕÊý¾Ý´íÎó,ÖØпªÊ¼½ÓÊÕ
}
}
}
}
#ifdef OS_TICKS_PER_SEC //Èç¹ûʱÖÓ½ÚÅÄÊý¶¨ÒåÁË,˵Ã÷ҪʹÓÃucosIIÁË.
OSIntExit();
#endif
}
#endif
usart.h
#ifndef __USART_H
#define __USART_H
#include "stdio.h"
#include "sys.h"
//STM32F103ºËÐÄ°åÀý³Ì
//¿âº¯Êý°æ±¾Àý³Ì
/********** mcudev.taobao.com ³öÆ· ********/
//
//STM32¿ª·¢°å
//´®¿Ú1³õʼ»¯
#define USART_REC_LEN 200 //¶¨Òå×î´ó½ÓÊÕ×Ö½ÚÊý 200
#define EN_USART1_RX 1 //ʹÄÜ£¨1£©/½ûÖ¹£¨0£©´®¿Ú1½ÓÊÕ
extern u8 USART_RX_BUF[USART_REC_LEN]; //½ÓÊÕ»º³å,×î´óUSART_REC_LEN¸ö×Ö½Ú.Ä©×Ö½ÚΪ»»Ðзû
extern u16 USART_RX_STA; //½ÓÊÕ״̬±ê¼Ç
//Èç¹ûÏë´®¿ÚÖжϽÓÊÕ£¬Ç벻ҪעÊÍÒÔϺ궨Òå
void uart_init(u32 bound);
#endif
bsp_i2c.c
#include "bsp_i2c.h"
#include "delay.h"
uint8_t ack_status=0;
uint8_t readByte[6];
uint8_t AHT20_status=0;
uint32_t H1=0; //Humility
uint32_t T1=0; //Temperature
uint8_t AHT20_OutData[4];
uint8_t AHT20sendOutData[10] = {0xFA, 0x06, 0x0A, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF};
void IIC_Init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd( RCC_APB2Periph_GPIOB, ENABLE );
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP ; //ÍÆÍìÊä³ö
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &GPIO_InitStructure);
IIC_SCL=1;
IIC_SDA=1;
}
//²úÉúIICÆðʼÐźÅ
void IIC_Start(void)
{
SDA_OUT(); //sdaÏßÊä³ö
IIC_SDA=1;
IIC_SCL=1;
delay_us(4);
IIC_SDA=0;//START:when CLK is high,DATA change form high to low
delay_us(4);
IIC_SCL=0;//ǯסI2C×ÜÏߣ¬×¼±¸·¢ËÍ»ò½ÓÊÕÊý¾Ý
}
//²úÉúIICÍ£Ö¹ÐźÅ
void IIC_Stop(void)
{
SDA_OUT();//sdaÏßÊä³ö
IIC_SCL=0;
IIC_SDA=0;//STOP:when CLK is high DATA change form low to high
delay_us(4);
IIC_SCL=1;
IIC_SDA=1;//·¢ËÍI2C×ÜÏß½áÊøÐźÅ
delay_us(4);
}
//µÈ´ýÓ¦´ðÐźŵ½À´
//·µ»ØÖµ£º1£¬½ÓÊÕÓ¦´ðʧ°Ü
// 0£¬½ÓÊÕÓ¦´ð³É¹¦
u8 IIC_Wait_Ack(void)
{
u8 ucErrTime=0;
SDA_IN(); //SDAÉèÖÃΪÊäÈë
IIC_SDA=1;delay_us(1);
IIC_SCL=1;delay_us(1);
while(READ_SDA)
{
ucErrTime++;
if(ucErrTime>250)
{
IIC_Stop();
return 1;
}
}
IIC_SCL=0;//ʱÖÓÊä³ö0
return 0;
}
//²úÉúACKÓ¦´ð
void IIC_Ack(void)
{
IIC_SCL=0;
SDA_OUT();
IIC_SDA=0;
delay_us(2);
IIC_SCL=1;
delay_us(2);
IIC_SCL=0;
}
//²»²úÉúACKÓ¦´ð
void IIC_NAck(void)
{
IIC_SCL=0;
SDA_OUT();
IIC_SDA=1;
delay_us(2);
IIC_SCL=1;
delay_us(2);
IIC_SCL=0;
}
//IIC·¢ËÍÒ»¸ö×Ö½Ú
//·µ»Ø´Ó»úÓÐÎÞÓ¦´ð
//1£¬ÓÐÓ¦´ð
//0£¬ÎÞÓ¦´ð
void IIC_Send_Byte(u8 txd)
{
u8 t;
SDA_OUT();
IIC_SCL=0;//ÀµÍʱÖÓ¿ªÊ¼Êý¾Ý´«Êä
for(t=0;t<8;t++)
{
IIC_SDA=(txd&0x80)>>7;
txd<<=1;
delay_us(2); //¶ÔTEA5767ÕâÈý¸öÑÓʱ¶¼ÊDZØÐëµÄ
IIC_SCL=1;
delay_us(2);
IIC_SCL=0;
delay_us(2);
}
}
//¶Á1¸ö×Ö½Ú£¬ack=1ʱ£¬·¢ËÍACK£¬ack=0£¬·¢ËÍnACK
u8 IIC_Read_Byte(unsigned char ack)
{
unsigned char i,receive=0;
SDA_IN();//SDAÉèÖÃΪÊäÈë
for(i=0;i<8;i++ )
{
IIC_SCL=0;
delay_us(2);
IIC_SCL=1;
receive<<=1;
if(READ_SDA)receive++;
delay_us(1);
}
if (!ack)
IIC_NAck();//·¢ËÍnACK
else
IIC_Ack(); //·¢ËÍACK
return receive;
}
void IIC_WriteByte(uint16_t addr,uint8_t data,uint8_t device_addr)
{
IIC_Start();
if(device_addr==0xA0) //eepromµØÖ·´óÓÚ1×Ö½Ú
IIC_Send_Byte(0xA0 + ((addr/256)<<1));//·¢Ë͸ߵØÖ·
else
IIC_Send_Byte(device_addr); //·¢Æ÷¼þµØÖ·
IIC_Wait_Ack();
IIC_Send_Byte(addr&0xFF); //·¢Ë͵͵ØÖ·
IIC_Wait_Ack();
IIC_Send_Byte(data); //·¢ËÍ×Ö½Ú
IIC_Wait_Ack();
IIC_Stop();//²úÉúÒ»¸öÍ£Ö¹Ìõ¼þ
if(device_addr==0xA0) //
delay_ms(10);
else
delay_us(2);
}
uint16_t IIC_ReadByte(uint16_t addr,uint8_t device_addr,uint8_t ByteNumToRead) //¶Á¼Ä´æÆ÷»ò¶ÁÊý¾Ý
{
uint16_t data;
IIC_Start();
if(device_addr==0xA0)
IIC_Send_Byte(0xA0 + ((addr/256)<<1));
else
IIC_Send_Byte(device_addr);
IIC_Wait_Ack();
IIC_Send_Byte(addr&0xFF); //·¢Ë͵͵ØÖ·
IIC_Wait_Ack();
IIC_Start();
IIC_Send_Byte(device_addr+1); //·¢Æ÷¼þµØÖ·
IIC_Wait_Ack();
if(ByteNumToRead == 1)//LM75ζÈÊý¾ÝΪ11bit
{
data=IIC_Read_Byte(0);
}
else
{
data=IIC_Read_Byte(1);
data=(data<<8)+IIC_Read_Byte(0);
}
IIC_Stop();//²úÉúÒ»¸öÍ£Ö¹Ìõ¼þ
return data;
}
/**********
*ÉÏÃ沿·ÖΪIO¿ÚÄ£¿éI2CÅäÖÃ
*
*´ÓÕâÒÔÏ¿ªÊ¼ÎªAHT20µÄÅäÖÃI2C
*º¯ÊýÃûÓÐIICºÍI2CµÄÇø±ð£¬Çë×¢Ò⣡£¡£¡£¡£¡
*
*2020/2/23×îºóÐÞ¸ÄÈÕÆÚ
*
***********/
void read_AHT20_once(void)
{
delay_ms(10);
reset_AHT20();
delay_ms(10);
init_AHT20();
delay_ms(10);
startMeasure_AHT20();
delay_ms(80);
read_AHT20();
delay_ms(5);
}
void reset_AHT20(void)
{
I2C_Start();
I2C_WriteByte(0x70);
ack_status = Receive_ACK();
if(ack_status) printf("1");
else printf("1-n-");
I2C_WriteByte(0xBA);
ack_status = Receive_ACK();
if(ack_status) printf("2");
else printf("2-n-");
I2C_Stop();
/*
AHT20_OutData[0] = 0;
AHT20_OutData[1] = 0;
AHT20_OutData[2] = 0;
AHT20_OutData[3] = 0;
*/
}
void init_AHT20(void)
{
I2C_Start();
I2C_WriteByte(0x70);
ack_status = Receive_ACK();
if(ack_status) printf("3");
else printf("3-n-");
I2C_WriteByte(0xE1);
ack_status = Receive_ACK();
if(ack_status) printf("4");
else printf("4-n-");
I2C_WriteByte(0x08);
ack_status = Receive_ACK();
if(ack_status) printf("5");
else printf("5-n-");
I2C_WriteByte(0x00);
ack_status = Receive_ACK();
if(ack_status) printf("6");
else printf("6-n-");
I2C_Stop();
}
void startMeasure_AHT20(void)
{
//------------
I2C_Start();
I2C_WriteByte(0x70);
ack_status = Receive_ACK();
if(ack_status) printf("7");
else printf("7-n-");
I2C_WriteByte(0xAC);
ack_status = Receive_ACK();
if(ack_status) printf("8");
else printf("8-n-");
I2C_WriteByte(0x33);
ack_status = Receive_ACK();
if(ack_status) printf("9");
else printf("9-n-");
I2C_WriteByte(0x00);
ack_status = Receive_ACK();
if(ack_status) printf("10");
else printf("10-n-");
I2C_Stop();
}
void read_AHT20(void)
{
uint8_t i;
for(i=0; i<6; i++)
{
readByte[i]=0;
}
//-------------
I2C_Start();
I2C_WriteByte(0x71);
ack_status = Receive_ACK();
readByte[0]= I2C_ReadByte();
Send_ACK();
readByte[1]= I2C_ReadByte();
Send_ACK();
readByte[2]= I2C_ReadByte();
Send_ACK();
readByte[3]= I2C_ReadByte();
Send_ACK();
readByte[4]= I2C_ReadByte();
Send_ACK();
readByte[5]= I2C_ReadByte();
SendNot_Ack();
//Send_ACK();
I2C_Stop();
//--------------
if( (readByte[0] & 0x68) == 0x08 )
{
H1 = readByte[1];
H1 = (H1<<8) | readByte[2];
H1 = (H1<<8) | readByte[3];
H1 = H1>>4;
H1 = (H1*1000)/1024/1024;
T1 = readByte[3];
T1 = T1 & 0x0000000F;
T1 = (T1<<8) | readByte[4];
T1 = (T1<<8) | readByte[5];
T1 = (T1*2000)/1024/1024 - 500;
AHT20_OutData[0] = (H1>>8) & 0x000000FF;
AHT20_OutData[1] = H1 & 0x000000FF;
AHT20_OutData[2] = (T1>>8) & 0x000000FF;
AHT20_OutData[3] = T1 & 0x000000FF;
}
else
{
AHT20_OutData[0] = 0xFF;
AHT20_OutData[1] = 0xFF;
AHT20_OutData[2] = 0xFF;
AHT20_OutData[3] = 0xFF;
printf("ʧ°ÜÁË");
}
printf("\r\n");
printf("ζÈ:%d%d.%d",T1/100,(T1/10)%10,T1%10);
printf("ʪ¶È:%d%d.%d",H1/100,(H1/10)%10,H1%10);
printf("\r\n");
}
uint8_t Receive_ACK(void)
{
uint8_t result=0;
uint8_t cnt=0;
IIC_SCL = 0;
SDA_IN();
delay_us(4);
IIC_SCL = 1;
delay_us(4);
while(READ_SDA && (cnt<100))
{
cnt++;
}
IIC_SCL = 0;
delay_us(4);
if(cnt<100)
{
result=1;
}
return result;
}
void Send_ACK(void)
{
SDA_OUT();
IIC_SCL = 0;
delay_us(4);
IIC_SDA = 0;
delay_us(4);
IIC_SCL = 1;
delay_us(4);
IIC_SCL = 0;
delay_us(4);
SDA_IN();
}
void SendNot_Ack(void)
{
SDA_OUT();
IIC_SCL = 0;
delay_us(4);
IIC_SDA = 1;
delay_us(4);
IIC_SCL = 1;
delay_us(4);
IIC_SCL = 0;
delay_us(4);
IIC_SDA = 0;
delay_us(4);
}
void I2C_WriteByte(uint8_t input)
{
uint8_t i;
SDA_OUT();
for(i=0; i<8; i++)
{
IIC_SCL = 0;
delay_ms(5);
if(input & 0x80)
{
IIC_SDA = 1;
//delaymm(10);
}
else
{
IIC_SDA = 0;
//delaymm(10);
}
IIC_SCL = 1;
delay_ms(5);
input = (input<<1);
}
IIC_SCL = 0;
delay_us(4);
SDA_IN();
delay_us(4);
}
uint8_t I2C_ReadByte(void)
{
uint8_t resultByte=0;
uint8_t i=0, a=0;
IIC_SCL = 0;
SDA_IN();
delay_ms(4);
for(i=0; i<8; i++)
{
IIC_SCL = 1;
delay_ms(3);
a=0;
if(READ_SDA)
{
a=1;
}
else
{
a=0;
}
//resultByte = resultByte | a;
resultByte = (resultByte << 1) | a;
IIC_SCL = 0;
delay_ms(3);
}
SDA_IN();
delay_ms(10);
return resultByte;
}
void set_AHT20sendOutData(void)
{
/* --------------------------
* 0xFA 0x06 0x0A temperature(2 Bytes) humility(2Bytes) short Address(2 Bytes)
* And Check (1 byte)
* -------------------------*/
AHT20sendOutData[3] = AHT20_OutData[0];
AHT20sendOutData[4] = AHT20_OutData[1];
AHT20sendOutData[5] = AHT20_OutData[2];
AHT20sendOutData[6] = AHT20_OutData[3];
// AHT20sendOutData[7] = (drf1609.shortAddress >> 8) & 0x00FF;
// AHT20sendOutData[8] = drf1609.shortAddress & 0x00FF;
// AHT20sendOutData[9] = getXY(AHT20sendOutData,10);
}
void I2C_Start(void)
{
SDA_OUT();
IIC_SCL = 1;
delay_ms(4);
IIC_SDA = 1;
delay_ms(4);
IIC_SDA = 0;
delay_ms(4);
IIC_SCL = 0;
delay_ms(4);
}
void I2C_Stop(void)
{
SDA_OUT();
IIC_SDA = 0;
delay_ms(4);
IIC_SCL = 1;
delay_ms(4);
IIC_SDA = 1;
delay_ms(4);
}
bsp_i2c.h
#ifndef __BSP_I2C_H
#define __BSP_I2C_H
#include "sys.h"
#include "delay.h"
#include "usart.h"
//ʹÓÃIIC1 ¹ÒÔØM24C02,OLED,LM75AD,HT1382 PB6,PB7
#define SDA_IN() {GPIOB->CRL&=0X0FFFFFFF;GPIOB->CRL|=(u32)8<<28;}
#define SDA_OUT() {GPIOB->CRL&=0X0FFFFFFF;GPIOB->CRL|=(u32)3<<28;}
//IO²Ù×÷º¯Êý
#define IIC_SCL PBout(6) //SCL
#define IIC_SDA PBout(7) //SDA
#define READ_SDA PBin(7) //ÊäÈëSDA
//IICËùÓвÙ×÷º¯Êý
void IIC_Init(void); //³õʼ»¯IICµÄIO¿Ú
void IIC_Start(void); //·¢ËÍIIC¿ªÊ¼ÐźÅ
void IIC_Stop(void); //·¢ËÍIICÍ£Ö¹ÐźÅ
void IIC_Send_Byte(u8 txd); //IIC·¢ËÍÒ»¸ö×Ö½Ú
u8 IIC_Read_Byte(unsigned char ack);//IIC¶ÁÈ¡Ò»¸ö×Ö½Ú
u8 IIC_Wait_Ack(void); //IICµÈ´ýACKÐźÅ
void IIC_Ack(void); //IIC·¢ËÍACKÐźÅ
void IIC_NAck(void); //IIC²»·¢ËÍACKÐźÅ
void IIC_WriteByte(uint16_t addr,uint8_t data,uint8_t device_addr);
uint16_t IIC_ReadByte(uint16_t addr,uint8_t device_addr,uint8_t ByteNumToRead);//¼Ä´æÆ÷µØÖ·£¬Æ÷¼þµØÖ·£¬Òª¶ÁµÄ×Ö½ÚÊý
void read_AHT20_once(void);
void reset_AHT20(void);
void init_AHT20(void);
void startMeasure_AHT20(void);
void read_AHT20(void);
uint8_t Receive_ACK(void);
void Send_ACK(void);
void SendNot_Ack(void);
void I2C_WriteByte(uint8_t input);
uint8_t I2C_ReadByte(void);
void set_AHT20sendOutData(void);
void I2C_Start(void);
void I2C_Stop(void);
#endif
delay.c
#include "delay.h"
#include "sys.h"
//STM32F103ºËÐÄ°åÀý³Ì
//¿âº¯Êý°æ±¾Àý³Ì
/********** mcudev.taobao.com ³öÆ· ********/
//
//Èç¹ûʹÓÃucos,Ôò°üÀ¨ÏÂÃæµÄÍ·Îļþ¼´¿É.
#if SYSTEM_SUPPORT_UCOS
#include "includes.h" //ucos ʹÓÃ
#endif
//
//STM32¿ª·¢°å
//ʹÓÃSysTickµÄÆÕͨ¼ÆÊýģʽ¶ÔÑÓ³Ù½øÐйÜÀí
//°üÀ¨delay_us,delay_ms
//
static u8 fac_us=0;//usÑÓʱ±¶³ËÊý
static u16 fac_ms=0;//msÑÓʱ±¶³ËÊý
#ifdef OS_CRITICAL_METHOD //Èç¹ûOS_CRITICAL_METHOD¶¨ÒåÁË,˵Ã÷ʹÓÃucosIIÁË.
//systickÖжϷþÎñº¯Êý,ʹÓÃucosʱÓõ½
void SysTick_Handler(void)
{
OSIntEnter(); //½øÈëÖжÏ
OSTimeTick(); //µ÷ÓÃucosµÄʱÖÓ·þÎñ³ÌÐò
OSIntExit(); //´¥·¢ÈÎÎñÇл»ÈíÖжÏ
}
#endif
//³õʼ»¯ÑÓ³Ùº¯Êý
//µ±Ê¹ÓÃucosµÄʱºò,´Ëº¯Êý»á³õʼ»¯ucosµÄʱÖÓ½ÚÅÄ
//SYSTICKµÄʱÖӹ̶¨ÎªHCLKʱÖÓµÄ1/8
//SYSCLK:ϵͳʱÖÓ
void delay_init()
{
#ifdef OS_CRITICAL_METHOD //Èç¹ûOS_CRITICAL_METHOD¶¨ÒåÁË,˵Ã÷ʹÓÃucosIIÁË.
u32 reload;
#endif
SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK_Div8); //Ñ¡ÔñÍⲿʱÖÓ HCLK/8
fac_us=SystemCoreClock/8000000; //ΪϵͳʱÖÓµÄ1/8
#ifdef OS_CRITICAL_METHOD //Èç¹ûOS_CRITICAL_METHOD¶¨ÒåÁË,˵Ã÷ʹÓÃucosIIÁË.
reload=SystemCoreClock/8000000; //ÿÃëÖӵļÆÊý´ÎÊý µ¥Î»ÎªK
reload*=1000000/OS_TICKS_PER_SEC;//¸ù¾ÝOS_TICKS_PER_SECÉ趨Òç³öʱ¼ä
//reloadΪ24λ¼Ä´æÆ÷,×î´óÖµ:16777216,ÔÚ72MÏÂ,Ô¼ºÏ1.86s×óÓÒ
fac_ms=1000/OS_TICKS_PER_SEC;//´ú±íucos¿ÉÒÔÑÓʱµÄ×îÉÙµ¥Î»
SysTick->CTRL|=SysTick_CTRL_TICKINT_Msk; //¿ªÆôSYSTICKÖжÏ
SysTick->LOAD=reload; //ÿ1/OS_TICKS_PER_SECÃëÖжÏÒ»´Î
SysTick->CTRL|=SysTick_CTRL_ENABLE_Msk; //¿ªÆôSYSTICK
#else
fac_ms=(u16)fac_us*1000;//·ÇucosÏÂ,´ú±íÿ¸ömsÐèÒªµÄsystickʱÖÓÊý
#endif
}
#ifdef OS_CRITICAL_METHOD //ʹÓÃÁËucos
//ÑÓʱnus
//nusΪҪÑÓʱµÄusÊý.
void delay_us(u32 nus)
{
u32 ticks;
u32 told,tnow,tcnt=0;
u32 reload=SysTick->LOAD; //LOADµÄÖµ
ticks=nus*fac_us; //ÐèÒªµÄ½ÚÅÄÊý
tcnt=0;
told=SysTick->VAL; //¸Õ½øÈëʱµÄ¼ÆÊýÆ÷Öµ
while(1)
{
tnow=SysTick->VAL;
if(tnow!=told)
{
if(tnow=ticks)break;//ʱ¼ä³¬¹ý/µÈÓÚÒªÑÓ³ÙµÄʱ¼ä,ÔòÍ˳ö.
}
};
}
//ÑÓʱnms
//nms:ÒªÑÓʱµÄmsÊý
void delay_ms(u16 nms)
{
if(OSRunning==TRUE)//Èç¹ûosÒѾÔÚÅÜÁË
{
if(nms>=fac_ms)//ÑÓʱµÄʱ¼ä´óÓÚucosµÄ×îÉÙʱ¼äÖÜÆÚ
{
OSTimeDly(nms/fac_ms);//ucosÑÓʱ
}
nms%=fac_ms; //ucosÒѾÎÞ·¨ÌṩÕâôСµÄÑÓʱÁË,²ÉÓÃÆÕͨ·½Ê½ÑÓʱ
}
delay_us((u32)(nms*1000)); //ÆÕͨ·½Ê½ÑÓʱ,´ËʱucosÎÞ·¨Æô¶¯µ÷¶È.
}
#else//²»ÓÃucosʱ
//ÑÓʱnus
//nusΪҪÑÓʱµÄusÊý.
void delay_us(u32 nus)
{
u32 temp;
SysTick->LOAD=nus*fac_us; //ʱ¼ä¼ÓÔØ
SysTick->VAL=0x00; //Çå¿Õ¼ÆÊýÆ÷
SysTick->CTRL|=SysTick_CTRL_ENABLE_Msk ; //¿ªÊ¼µ¹Êý
do
{
temp=SysTick->CTRL;
}
while(temp&0x01&&!(temp&(1<<16)));//µÈ´ýʱ¼äµ½´ï
SysTick->CTRL&=~SysTick_CTRL_ENABLE_Msk; //¹Ø±Õ¼ÆÊýÆ÷
SysTick->VAL =0X00; //Çå¿Õ¼ÆÊýÆ÷
}
//ÑÓʱnms
//×¢ÒânmsµÄ·¶Î§
//SysTick->LOADΪ24λ¼Ä´æÆ÷,ËùÒÔ,×î´óÑÓʱΪ:
//nms<=0xffffff*8*1000/SYSCLK
//SYSCLKµ¥Î»ÎªHz,nmsµ¥Î»Îªms
//¶Ô72MÌõ¼þÏÂ,nms<=1864
void delay_ms(u16 nms)
{
u32 temp;
SysTick->LOAD=(u32)nms*fac_ms;//ʱ¼ä¼ÓÔØ(SysTick->LOADΪ24bit)
SysTick->VAL =0x00; //Çå¿Õ¼ÆÊýÆ÷
SysTick->CTRL|=SysTick_CTRL_ENABLE_Msk ; //¿ªÊ¼µ¹Êý
do
{
temp=SysTick->CTRL;
}
while(temp&0x01&&!(temp&(1<<16)));//µÈ´ýʱ¼äµ½´ï
SysTick->CTRL&=~SysTick_CTRL_ENABLE_Msk; //¹Ø±Õ¼ÆÊýÆ÷
SysTick->VAL =0X00; //Çå¿Õ¼ÆÊýÆ÷
}
#endif
delay.h
#ifndef __DELAY_H
#define __DELAY_H
#include "sys.h"
//
//STM32F103ºËÐÄ°åÀý³Ì
//¿âº¯Êý°æ±¾Àý³Ì
/********** mcudev.taobao.com ³öÆ· ********/
//ʹÓÃSysTickµÄÆÕͨ¼ÆÊýģʽ¶ÔÑÓ³Ù½øÐйÜÀí
//°üÀ¨delay_us,delay_ms
//
void delay_init(void);
void delay_ms(u16 nms);
void delay_us(u32 nus);
#endif
sys.c
#include "sys.h"
//STM32F103ºËÐÄ°åÀý³Ì
//¿âº¯Êý°æ±¾Àý³Ì
/********** mcudev.taobao.com ³öÆ· ********/
//
//STM32¿ª·¢°å
//ϵͳÖжϷÖ×éÉèÖû¯
//********************************************************************************
void NVIC_Configuration(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //ÉèÖÃNVICÖжϷÖ×é2:2λÇÀÕ¼ÓÅÏȼ¶£¬2λÏìÓ¦ÓÅÏȼ¶
}
sys.h
#ifndef __SYS_H
#define __SYS_H
#include "stm32f10x.h"
//
//STM32F103ºËÐÄ°åÀý³Ì
//¿âº¯Êý°æ±¾Àý³Ì
/********** mcudev.taobao.com ³öÆ· ********/
//
//0,²»Ö§³Öucos
//1,Ö§³Öucos
#define SYSTEM_SUPPORT_UCOS 0 //¶¨ÒåϵͳÎļþ¼ÐÊÇ·ñÖ§³ÖUCOS
//λ´ø²Ù×÷,ʵÏÖ51ÀàËƵÄGPIO¿ØÖƹ¦ÄÜ
//¾ßÌåʵÏÖ˼Ïë,²Î¿¼<>µÚÎåÕÂ(87Ò³~92Ò³).
//IO¿Ú²Ù×÷ºê¶¨Òå
#define BITBAND(addr, bitnum) ((addr & 0xF0000000)+0x2000000+((addr &0xFFFFF)<<5)+(bitnum<<2))
#define MEM_ADDR(addr) *((volatile unsigned long *)(addr))
#define BIT_ADDR(addr, bitnum) MEM_ADDR(BITBAND(addr, bitnum))
//IO¿ÚµØÖ·Ó³Éä
#define GPIOA_ODR_Addr (GPIOA_BASE+12) //0x4001080C
#define GPIOB_ODR_Addr (GPIOB_BASE+12) //0x40010C0C
#define GPIOC_ODR_Addr (GPIOC_BASE+12) //0x4001100C
#define GPIOD_ODR_Addr (GPIOD_BASE+12) //0x4001140C
#define GPIOE_ODR_Addr (GPIOE_BASE+12) //0x4001180C
#define GPIOF_ODR_Addr (GPIOF_BASE+12) //0x40011A0C
#define GPIOG_ODR_Addr (GPIOG_BASE+12) //0x40011E0C
#define GPIOA_IDR_Addr (GPIOA_BASE+8) //0x40010808
#define GPIOB_IDR_Addr (GPIOB_BASE+8) //0x40010C08
#define GPIOC_IDR_Addr (GPIOC_BASE+8) //0x40011008
#define GPIOD_IDR_Addr (GPIOD_BASE+8) //0x40011408
#define GPIOE_IDR_Addr (GPIOE_BASE+8) //0x40011808
#define GPIOF_IDR_Addr (GPIOF_BASE+8) //0x40011A08
#define GPIOG_IDR_Addr (GPIOG_BASE+8) //0x40011E08
//IO¿Ú²Ù×÷,Ö»¶Ôµ¥Ò»µÄIO¿Ú!
//È·±£nµÄֵСÓÚ16!
#define PAout(n) BIT_ADDR(GPIOA_ODR_Addr,n) //Êä³ö
#define PAin(n) BIT_ADDR(GPIOA_IDR_Addr,n) //ÊäÈë
#define PBout(n) BIT_ADDR(GPIOB_ODR_Addr,n) //Êä³ö
#define PBin(n) BIT_ADDR(GPIOB_IDR_Addr,n) //ÊäÈë
#define PCout(n) BIT_ADDR(GPIOC_ODR_Addr,n) //Êä³ö
#define PCin(n) BIT_ADDR(GPIOC_IDR_Addr,n) //ÊäÈë
#define PDout(n) BIT_ADDR(GPIOD_ODR_Addr,n) //Êä³ö
#define PDin(n) BIT_ADDR(GPIOD_IDR_Addr,n) //ÊäÈë
#define PEout(n) BIT_ADDR(GPIOE_ODR_Addr,n) //Êä³ö
#define PEin(n) BIT_ADDR(GPIOE_IDR_Addr,n) //ÊäÈë
#define PFout(n) BIT_ADDR(GPIOF_ODR_Addr,n) //Êä³ö
#define PFin(n) BIT_ADDR(GPIOF_IDR_Addr,n) //ÊäÈë
#define PGout(n) BIT_ADDR(GPIOG_ODR_Addr,n) //Êä³ö
#define PGin(n) BIT_ADDR(GPIOG_IDR_Addr,n) //ÊäÈë
void NVIC_Configuration(void);
#endif
然后把usart.c，bsp_i2c.c，delay.c，sys.c加到工程文件中
3.烧录
4.结果
三.总结
这次实验是通过串口输出温湿度传感器所感受的温湿度，通过这次实验我了解了I2C的软件和硬件的内容和区别，并且认识了AHT20温湿度传感器这一传感器。
四.参考资料
stm32通过I2C接口实现温湿度（AHT20）的采集