stm32-HTU21D例程.doc

#include Anal_I2C.h#include HTU21D.h#include Kalman.h#include math.h#define A 8.1332f#define B 1762.39f#define C 235.66fHTU21D_Struct HTU;Kalman_Data_Struct Kalman_Temperature_Data,Kalman_Dew_Data;float Dew_Q=1,Dew_R=400;void Data_Send_3Axis(int16_t x,int16_t y,int16_t z);uint8_t HTU21D_Check_CRC(uint16_t message_from_sensor, uint8_t check_value_from_sensor);uint8_t Read_User_Register(void)uint8_t User_Reg;Anal_I2C_START();Anal_I2C_SendByte(0x80); /写地址Anal_I2C_SendByte(0xe7); /写入读指令Anal_I2C_START();Anal_I2C_SendByte(0x81); /读地址while (!Anal_I2C_SCL_STATE);User_Reg=Anal_I2C_ReceiveByte(); /读取/Anal_I2C_ReceiveBuf(User_Reg,1);Anal_I2C_STOP(); return User_Reg;float Read_Temperature(void)uint8_t Tem_Reg3;uint16_t Temp=0;float T;Anal_I2C_START();Anal_I2C_SendByte(0x80); /写地址Anal_I2C_SendByte(0xe3); /e3触发温度测量 e5湿度Anal_I2C_START();Anal_I2C_SendByte(0x81); /读地址while (!Anal_I2C_SCL_STATE);Anal_I2C_ReceiveBuf(Tem_Reg,3); Anal_I2C_STOP();Temp= ( (Temp|Tem_Reg0) 8 ) | Tem_Reg1 ;if(HTU21D_Check_CRC(Temp,Tem_Reg2)=0) /CRC-8校验Temp&=0xfffc;T=Temp*175.72f/0xffff-46.85f;/Data_Send_3Axis(T*100.0f,2,3);/return KalmanFilter(T,&Kalman_Temperature_Data,1,1);return T;elsereturn 999;float Read_Humidity(void)uint8_t Hum_Reg4;uint16_t Temp=0;float RT;Anal_I2C_START();Anal_I2C_SendByte(0x80); /写地址Anal_I2C_SendByte(0xe5); /e3触发温度测量 e5湿度Anal_I2C_START();Anal_I2C_SendByte(0x81); /读地址while (!Anal_I2C_SCL_STATE);Anal_I2C_ReceiveBuf(Hum_Reg,3); Anal_I2C_STOP();Temp= ( (Temp|Hum_Reg0) 8 ) | Hum_Reg1 ;if(HTU21D_Check_CRC(Temp,Hum_Reg2)=0) /CRC-8校验Temp&=0xfffc;RT=Temp*125.0f/0xffff-6.0f;/Data_Send_3Axis(Hum_Reg0,Hum_Reg1,RT);/return KalmanFilter(RT,&Kalman_Humidity_Data,Humidity_Q,Humidity_R);return RT;elsereturn 999;void HTU21D_Init(void)Anal_I2C_START();Anal_I2C_SendByte(0x80); /写地址Anal_I2C_SendByte(0xe6); /写入写指令Anal_I2C_SendByte(0x83); /读地址/Anal_I2C_ReceiveBuf(User_Reg,1);Anal_I2C_STOP();/*/两个参数一个是传感器的源数据，另一个是传感器得出的CRC校验值/如果校验通过返回0，不通过返回非0/From: /avr-libc/user-manual/group_util_crc.html/POLYNOMIAL = 0x0131 = x8 + x5 + x4 + 1 : /wiki/Computation_of_cyclic_redundancy_checks#define SHIFTED_DIVISOR 0x988000 /This is the 0x0131 polynomial shifted to farthest left of three bytes/*uint8_t HTU21D_Check_CRC(uint16_t message_from_sensor, uint8_t check_value_from_sensor)uint8_t i; /Test cases from datasheet: /message = 0xDC, checkvalue is 0x79 /message = 0x683A, checkvalue is 0x7C /message = 0x4E85, checkvalue is 0x6B uint32_t remainder = (uint32_t)message_from_sensor 8; /Pad with 8 bits because we have to add in the check value uint32_t divsor = (uint32_t)SHIFTED_DIVISOR; remainder |= check_value_from_sensor; /Add on the check value for (i = 0 ; i 16 ; i+) /Operate on only 16 positions of max 24. The remaining 8 are our remainder and should be zero when were done. if( remainder & (uint32_t)1= 1; /Rotate the divsor max 16 times so that we have 8 bits left of a remainder return (uint8_t)remainder;void Updata_HTU(void)float temp;if(temp=Read_Temperature()!=999)HTU.T=temp;if(temp=Read_Humidity()!=999)HTU.RH=temp;temp=Calc_Dewpoint(HTU.RH,HTU.T);HTU.Dew=KalmanFilter(temp,&Kalman_Dew_Data,Dew_Q,Dew_R);float Calc_Dewpoint(float RH,float T)float PP,T_Dew;PP=powf(10, A-B/(T+C);T_Dew=-(B/(log10f(RH*PP/100.0f)-A ) +C);return T_Dew;/头文件#ifndef _HTU21D_H_#define _HTU21D_H_#include typedef structfloat T;float RH;float T_Set;float RH_Set;float Dew;float Dew_Set; HTU21D_Struct;extern HTU21D_Struct HTU;extern float Dew_Q,D