Stm32f103ze+sht30 detection of ambient temperature and humidity (IIC simulation sequence)

One 、 Introduction to the environment

Engineering compilation software : keil5

Temperature and humidity sensor : SHT30

MCU : STM32F103ZET6

The program adopts modular programming ,iic The timing is a module (iic.c and iic.h),SHT30 For a module (sht30.c and sht30.h);IIC The timing is realized by analog timing ,IO Macro definition method is adopted for all interfaces , It is convenient to quickly migrate to other platforms .

Two 、SHT30 Introduce

characteristic :

\1. Humidity and temperature sensors
\2. Full calibration 、 Linearization and temperature
\3. Compensated digital output , Wide power supply voltage range , from 2.4 V To 5.5 V
\4. I2C Interface , The communication speed is up to 1MHz And two user selectable addresses
\5. Typical accuracy ± 2% Relative humidity and ± 0.3°C
\6. Start up and measurement time is very fast
\7. miniature 8 The needle DFN encapsulation

This is a SHT30 Of 7 position IIC Device address :

3、 ... and 、 Equipment operation effect

This is the data printed by serial port :

Four 、 Device code

4.1 main.c

#include "stm32f10x.h"#include "led.h"#include "delay.h"#include "key.h"#include "usart.h"#include "iic.h"#include "sht3x.h"int main(){   float Humidity;   float Temperature;   USART1_Init(115200);   USART1_Printf(" The equipment is running normally ....\r\n");   IIC_Init();    Init_SHT30();   while(1)   {       // Read the temperature and humidity        SHT3x_ReadData(&Humidity,&Temperature);       USART1_Printf(" temperature :%0.2f, humidity :%0.2f\r\n",Temperature,Humidity);       delay_ms(1000);   }}

4.2 sht30.c

#include "sht3x.h"const int16_t POLYNOMIAL = 0x131;/****************************************************************  The name of the function : SHT30_reset*  say   bright : SHT30 Reset *  ginseng   Count :  nothing *  return   return   value :  nothing ***************************************************************/void SHT30_reset(void){    u8 r_s;        IIC_Start(); // Send the start signal         IIC_WriteOneByteData(SHT30_AddrW); // Write the device address     r_s=IIC_GetACK();// Get answers     if(r_s)printf("Init_SHT30_error:1\r\n");    IIC_WriteOneByteData(0x30); // Writing data     r_s=IIC_GetACK();// Get answers     if(r_s)printf("Init_SHT30_error:2\r\n");        IIC_WriteOneByteData(0xA2); // Writing data     r_s=IIC_GetACK();// Get answers     if(r_s)printf("Init_SHT30_error:3\r\n");        IIC_Stop(); // Stop signal      delay_ms(50);    }/****************************************************************  The name of the function : Init_SHT30*  say   bright :  initialization SHT30, Set the measurement cycle *  ginseng   Count :  nothing *  return   return   value :  nothing ***************************************************************/void Init_SHT30(void){     u8 r_s;        IIC_Start(); // Send the start signal         IIC_WriteOneByteData(SHT30_AddrW); // Write the device address     r_s=IIC_GetACK();// Get answers     if(r_s)printf("Init_SHT30_error:1\r\n");    IIC_WriteOneByteData(0x22); // Writing data     r_s=IIC_GetACK();// Get answers     if(r_s)printf("Init_SHT30_error:2\r\n");        IIC_WriteOneByteData(0x36); // Writing data     r_s=IIC_GetACK();// Get answers     if(r_s)printf("Init_SHT30_error:3\r\n");        IIC_Stop(); // Stop signal          delay_ms(200);}/****************************************************************  The name of the function : SHT3x_CheckCrc*  say   bright :  Check the correctness of the data *  ginseng   Count : data： Data read  nbrOfBytes： Quantity to be verified  checksum： The read calibration comparison value *  return   return   value :  Verification results ,0- success  1- Failure ***************************************************************/u8 SHT3x_CheckCrc(char data[], char nbrOfBytes, char checksum){	    char crc = 0xFF;    char bit = 0;    char byteCtr ;	    //calculates 8-Bit checksum with given polynomial    for(byteCtr = 0; byteCtr < nbrOfBytes; ++byteCtr)    {        crc ^= (data[byteCtr]);        for ( bit = 8; bit > 0; --bit)        {            if (crc & 0x80) crc = (crc << 1) ^ POLYNOMIAL;            else crc = (crc << 1);        }    }	    if(crc != checksum)		return 1;    else		return 0;	}/****************************************************************  The name of the function : SHT3x_CalcTemperatureC*  say   bright :  Temperature calculation *  ginseng   Count : u16sT： Read the raw temperature data *  return   return   value :  Calculated temperature data ***************************************************************/float SHT3x_CalcTemperatureC(unsigned short u16sT){	    float temperatureC = 0;            // variable for result    u16sT &= ~0x0003;           // clear bits [1..0] (status bits)    //-- calculate temperature [℃] --    temperatureC = (175 * (float)u16sT / 65535 - 45); //T = -45 + 175 * rawValue / (2^16-1)	    return temperatureC;	}/****************************************************************  The name of the function : SHT3x_CalcRH*  say   bright :  Humidity calculation *  ginseng   Count : u16sRH： Read humidity raw data *  return   return   value :  Calculated humidity data ***************************************************************/float SHT3x_CalcRH(unsigned short u16sRH){	    float humidityRH = 0;              // variable for result	    u16sRH &= ~0x0003;          // clear bits [1..0] (status bits)    //-- calculate relative humidity [%RH] --    humidityRH = (100 * (float)u16sRH / 65535);  // RH = rawValue / (2^16-1) * 10	    return humidityRH;	}// Read temperature and humidity data void SHT3x_ReadData(float *Humidity,float *Temperature){    char  data[3];    //data array for checksum verification    u8 SHT3X_Data_Buffer[6]; 																		//byte 0,1 is temperature byte 4,5 is humidity    u8 r_s=0;    u8 i;    unsigned short tmp = 0;    uint16_t dat;        IIC_Start(); // Send the start signal         IIC_WriteOneByteData(SHT30_AddrW); // Write the device address     r_s=IIC_GetACK();// Get answers     if(r_s)printf("SHT3X_error:1\r\n");    IIC_WriteOneByteData(0xE0); // Writing data     r_s=IIC_GetACK();// Get answers     if(r_s)printf("SHT3X_error:2\r\n");        IIC_WriteOneByteData(0x00); // Writing data     r_s=IIC_GetACK();// Get answers     if(r_s)printf("SHT3X_error:3\r\n");        //IIC_Stop(); // Stop signal         // DelayMs(30); // wait for         // Read sht30 Sensor data     IIC_Start(); // Send the start signal     IIC_WriteOneByteData(SHT30_AddrR);    r_s=IIC_GetACK();// Get answers     if(r_s)printf("SHT3X_error:7\r\n");        for(i=0;i<6;i++)    {        SHT3X_Data_Buffer[i]=IIC_ReadOneByteData(); // receive data         if(i==5)        {             IIC_SendACK(1); // Send non reply signal             break;        }        IIC_SendACK(0); // Send reply signal     }    IIC_Stop(); // Stop signal         // /* check tem */    data[0] = SHT3X_Data_Buffer[0];    data[1] = SHT3X_Data_Buffer[1];    data[2] = SHT3X_Data_Buffer[2];    tmp=SHT3x_CheckCrc(data, 2, data[2]);    if( !tmp ) /* value is ture */    {        dat = ((uint16_t)data[0] << 8) | data[1];        *Temperature = SHT3x_CalcTemperatureC( dat );        }    // /* check humidity */    data[0] = SHT3X_Data_Buffer[3];    data[1] = SHT3X_Data_Buffer[4];    data[2] = SHT3X_Data_Buffer[5];    tmp=SHT3x_CheckCrc(data, 2, data[2]);    if( !tmp ) /* value is ture */    {        dat = ((uint16_t)data[0] << 8) | data[1];        *Humidity = SHT3x_CalcRH( dat );        }}

4.3 iic.c

#include "iic.h"/* The functionality ：IIC Interface initialization hardware connection ：SDA：PB7SCL：PB6*/void IIC_Init(void){	RCC->APB2ENR|=1<<3;//PB	GPIOB->CRL&=0x00FFFFFF;	GPIOB->CRL|=0x33000000;	GPIOB->ODR|=0x3<<6;}/* The functionality ：IIC Bus start signal */void IIC_Start(void){    IIC_SDA_OUTMODE(); // initialization SDA For output mode     IIC_SDA_OUT=1; 		 // The data cable is pulled high     IIC_SCL=1;     		 // Pull the clock cable high     DelayUs(4);        // Level holding time     IIC_SDA_OUT=0; 		 // Pull down the data cable     DelayUs(4);        // Level holding time     IIC_SCL=0;     		 // Pull down the clock line }/* The functionality ：IIC Bus stop signal */void IIC_Stop(void){		IIC_SDA_OUTMODE(); // initialization SDA For output mode 		IIC_SDA_OUT=0; 		 // Pull down the data cable 		IIC_SCL=0;     		 // Pull down the clock line 		DelayUs(4);        // Level holding time 		IIC_SCL=1;     		 // Pull the clock cable high 		DelayUs(4);        // Level holding time 		IIC_SDA_OUT=1; 		 // The data cable is pulled high }/* The functionality ： Get the reply signal and return   return   value ：1 It means failure ,0 It means success */u8 IIC_GetACK(void){		u8 cnt=0;		IIC_SDA_INPUTMODE();// initialization SDA Is the input mode 		IIC_SDA_OUT=1; 		  // Data online pull 	  DelayUs(2);         // Level holding time 		IIC_SCL=0;     		  // Pull down the clock line , Tell the slave , The host needs data 		DelayUs(2);         // Level holding time , Wait for the slave to send data 	  IIC_SCL=1;     		  // Pull the clock cable high , Tell the slave , The host now starts reading data 		while(IIC_SDA_IN)   // Waiting for the slave to respond 		{				cnt++;				if(cnt>250)return 1;		}		IIC_SCL=0;     		  // Pull down the clock line , Tell the slave , The host needs data 		return 0;}/* The functionality ： The master sends the response signal function parameter to the slave ：0 To answer ,1 It means no response */void IIC_SendACK(u8 stat){		IIC_SDA_OUTMODE(); // initialization SDA For output mode 		IIC_SCL=0;     		 // Pull down the clock line , Tell the slave , The host needs to send data 		if(stat)IIC_SDA_OUT=1; // The data cable is pulled high , Send non reply signal 		else IIC_SDA_OUT=0; 	 // Pull down the data cable , Send reply signal 		DelayUs(2);            // Level holding time , Wait for the clock line to stabilize 		IIC_SCL=1;     		     // Pull the clock cable high , Tell the slave , The host data has been sent 		DelayUs(2);            // Level holding time , Wait for the slave to receive data 		IIC_SCL=0;     		  	 // Pull down the clock line , Tell the slave , The host needs data }/* The functionality ：IIC send out 1 Byte data function parameters ： Data to be sent */void IIC_WriteOneByteData(u8 data){		u8 i;		IIC_SDA_OUTMODE(); // initialization SDA For output mode 		IIC_SCL=0;     		 // Pull down the clock line , Tell the slave , The host needs to send data 		for(i=0;i<8;i++)		{				if(data&0x80)IIC_SDA_OUT=1; // The data cable is pulled high , send out 1				else IIC_SDA_OUT=0; 	 // Pull down the data cable , send out 0				IIC_SCL=1;     		     // Pull the clock cable high , Tell the slave , The host data has been sent 				DelayUs(2);            // Level holding time , Wait for the slave to receive data 				IIC_SCL=0;     		 		 // Pull down the clock line , Tell the slave , The host needs to send data 				DelayUs(2);            // Level holding time , Wait for the clock line to stabilize 				data<<=1;              // First mover 		}}/* The functionality ：IIC receive 1 Bytes of data are returned   return   value ： Data received */u8 IIC_ReadOneByteData(void){		u8 i,data;		IIC_SDA_INPUTMODE();// initialization SDA Is the input mode 	  for(i=0;i<8;i++)	  {			 	IIC_SCL=0;     		  // Pull down the clock line , Tell the slave , The host needs data 				DelayUs(2);         // Level holding time , Wait for the slave to send data 				IIC_SCL=1;     		  // Pull the clock cable high , Tell the slave , The host is now reading data 				data<<=1;           				if(IIC_SDA_IN)data|=0x01;				DelayUs(2);         // Level holding time , Wait for the clock line to stabilize 	  }		IIC_SCL=0;     		  		// Pull down the clock line , Tell the slave , The host needs data  ( Must be pulled down , Otherwise, it will be recognized as a stop signal )		return data;}