我使用SHT21传感器运行此代码以读取温度和湿度：
#include <Wire.h>
#include <Ports.h>
#include "PortsSHT21.h"
#include <SHT2x.h>
//Define soft i2c channels for a sensor
SHT21 hsensor2 (2); // pins A1 and D5 - Sensor 2
//define variables for temp data
float h, t;
void setup()
{
Wire.begin();
Serial.begin(9600);
}
void loop()
{
// Get data from sensor soft I2C
hsensor2.measure(SHT21::HUMI);
hsensor2.measure(SHT21::TEMP);
hsensor2.calculate(h, t);
float hum2 = (h);
float temp2 = (t);
Serial.println("temp2");
Serial.println(temp2);
delay(500);
}
但总是回归-46.85度。可以找到here is PortsSHT21.cpp code和PortsSHT21.h的源代码here
似乎PortsSHT21.cpp文件的这一部分（第114行）总是为＃34; meas [TEMP]＆＃34;变量
t_C = (175.72 / 16384.0) * meas[TEMP] - 46.85; //T= -46.85 + 175.72 * ST/2^16
请你帮我解决这个问题吗？
答案 0 :(得分：0)
该传感器看起来与HTU21D和Si7021单元完全相同。地址和转换常量是相同的。确认硬件设置后，我建议，作为调试步骤，尝试其中一个库。我已经成功地使用Si7021替代（没有软件更改）烧毁HTU21D。看起来SHT21芯片也使用相同的I2C接口。
答案 1 :(得分：-1)
使用此温度读取功能。这还会读取多个测量值并获得平均值。
bool Air_Temperature(int Read_Count, int AVG_Type, float &Value_, double &Deviation_) {
/******************************************************************************
* Project : SHT21 Temperature Read Function
* Developer : Mehmet Gunce Akkoyun (gunce.akkoyun@noxcorp.org)
* Revision : 03.13.00
* Relase : 19.12.2018
* AVG Type : 1-AVG, 2-RMS, 3-EXRMS, 4-MEDIAN, 5-Sigma1RMS
******************************************************************************/
// Set Sensor Definations
struct Sensor_Settings {
int Resolution;
bool EoB;
bool OCH;
bool OTP;
int Range_Min;
int Range_Max;
};
Sensor_Settings SHT21[] {
{
14, // Measurement Resolution
false, // Sensor End of Battery Setting
false, // On Chip Heater Setting
true, // OTP Read
-40, // Sensor Range Minimum
100 // Sensor Range Maximum
}
};
// Control Read Count
if (Read_Count < 01) Read_Count = 01;
if (Read_Count > 50) Read_Count = 50;
// ************************************************************
// Set Sensor Configuration Byte
// ************************************************************
// User Register Bit Definations
bool User_Reg_Bits_[8] = {false, false, false, false, false, false, false, false};
// Set Resolution Bits
if (SHT21[0].Resolution == 14) { User_Reg_Bits_[7] = false ; User_Reg_Bits_[0] = false ;} // T: 14 bit
if (SHT21[0].Resolution == 12) { User_Reg_Bits_[7] = false ; User_Reg_Bits_[0] = true ;} // T: 12 bit
if (SHT21[0].Resolution == 13) { User_Reg_Bits_[7] = true ; User_Reg_Bits_[0] = false ;} // T: 13 bit
if (SHT21[0].Resolution == 11) { User_Reg_Bits_[7] = true ; User_Reg_Bits_[0] = true ;} // T: 11 bit
// Set End of Battery Bits
if (SHT21[0].EoB == true) {User_Reg_Bits_[6] = true;} else {User_Reg_Bits_[6] = false;}
// On Chip Heater Bits
if (SHT21[0].OCH == true) {User_Reg_Bits_[2] = true;} else {User_Reg_Bits_[2] = false;}
// OTP Reload Bits
if (SHT21[0].OTP == true) {User_Reg_Bits_[1] = true;} else {User_Reg_Bits_[1] = false;}
// User Register Defination
uint8_t User_Reg_ = 0x00;
// Set Config Register
if (User_Reg_Bits_[0] == true) {User_Reg_ |= 0b00000001;} else {User_Reg_ &= 0b11111110;} // User Register Bit 0
if (User_Reg_Bits_[1] == true) {User_Reg_ |= 0b00000010;} else {User_Reg_ &= 0b11111101;} // User Register Bit 1
if (User_Reg_Bits_[2] == true) {User_Reg_ |= 0b00000100;} else {User_Reg_ &= 0b11111011;} // User Register Bit 2
if (User_Reg_Bits_[3] == true) {User_Reg_ |= 0b00001000;} else {User_Reg_ &= 0b11110111;} // User Register Bit 3
if (User_Reg_Bits_[4] == true) {User_Reg_ |= 0b00010000;} else {User_Reg_ &= 0b11101111;} // User Register Bit 4
if (User_Reg_Bits_[5] == true) {User_Reg_ |= 0b00100000;} else {User_Reg_ &= 0b11011111;} // User Register Bit 5
if (User_Reg_Bits_[6] == true) {User_Reg_ |= 0b01000000;} else {User_Reg_ &= 0b10111111;} // User Register Bit 6
if (User_Reg_Bits_[7] == true) {User_Reg_ |= 0b10000000;} else {User_Reg_ &= 0b01111111;} // User Register Bit 7
// ************************************************************
// Reset Sensor
// ************************************************************
// Send Soft Reset Command to SHT21
Wire.beginTransmission(0b01000000);
Wire.write(0b11111110);
// Close I2C Connection
int SHT21_Reset = Wire.endTransmission(false);
// Control For Reset Success
if (SHT21_Reset != 0) {
// Set Error Code
Value_ = -101;
// End Function
return(false);
}
// Software Reset Delay
delay(15);
// ************************************************************
// Read Current Sensor Settings
// ************************************************************
// Read User Register of SHT21
Wire.beginTransmission(0b01000000);
Wire.write(0b11100110);
Wire.requestFrom(0b01000000, 1);
uint8_t SHT21_Config_Read = Wire.read();
// ************************************************************
// Write New Settings if Different
// ************************************************************
// Control for Config Read Register
if (SHT21_Config_Read != User_Reg_) {
// Write User Register of SHT21
Wire.beginTransmission(0b01000000);
Wire.write(0b11100110);
Wire.write(User_Reg_);
// Close I2C Connection
int SHT21_Config = Wire.endTransmission(false);
// Control For Command Success
if (SHT21_Config != 0) {
// Set Error Code
Value_ = -102;
// End Function
return(false);
}
}
// ************************************************************
// Read Sensor Datas
// ************************************************************
// Define Measurement Read Array
float Measurement_Array[Read_Count];
// Read Loop For Read Count
for (int Read_ID = 0; Read_ID < Read_Count; Read_ID++) {
// Define Variables
uint16_t Measurement_Raw = 0;
// Send Read Command to SHT21
Wire.beginTransmission(0b01000000);
Wire.write(0b11100011);
// Close I2C Connection
int SHT21_Read = Wire.endTransmission(false);
// Control For Read Success
if (SHT21_Read != 0) {
// Set Error Code
Value_ = -103;
// End Function
return(false);
}
// Read Data Command to SHT21
Wire.requestFrom(0b01000000, 3);
// Define Data Variable
uint8_t SHT21_Data[3];
// Read I2C Bytes
SHT21_Data[0] = Wire.read(); // MSB
SHT21_Data[1] = Wire.read(); // LSB
SHT21_Data[2] = Wire.read(); // CRC
// Combine Read Bytes
Measurement_Raw = ((SHT21_Data[0] << 8) | SHT21_Data[1]);
// Clear 2 Low Status Bit
if (SHT21[0].Resolution == 11) Measurement_Raw &= ~0x0006;
if (SHT21[0].Resolution == 12) Measurement_Raw &= ~0x0005;
if (SHT21[0].Resolution == 13) Measurement_Raw &= ~0x0004;
if (SHT21[0].Resolution == 14) Measurement_Raw &= ~0x0003;
// Define CRC Variables
uint8_t CRC, Control_Byte;
// Calculate CRC
for (Control_Byte = 0; Control_Byte < 3; Control_Byte++) {
CRC ^= SHT21_Data[Control_Byte];
for (uint8_t bit = 8; bit > 0; bit--) {
if (CRC & 0x80) {CRC = (CRC << 1) ^ 0x131;}
else { CRC = (CRC << 1);}
}
}
// Control and Calculate Measurement
if (CRC == 0) {
// Calculate Measurement
Measurement_Array[Read_ID] = -46.85 + ((175.72 * float(Measurement_Raw)) / pow(2,16));
} else {
// Set Error Code
Value_ = -104;
// End Function
return(false);
}
// Read Delay
if (SHT21[0].Resolution == 14) delay(85); // T: 14 bit
if (SHT21[0].Resolution == 12) delay(22); // T: 12 bit
if (SHT21[0].Resolution == 13) delay(43); // T: 13 bit
if (SHT21[0].Resolution == 11) delay(11); // T: 11 bit
}
// ************************************************************
// Calculate Value for Average Type
// ************************************************************
// Control Read Count for Average Type
if (Read_Count < 3 and AVG_Type == 3) AVG_Type = 2;
// Calculate Average
if (AVG_Type == 1) {
// ************************************************************
// Calculate Aritmetic Average With Measurement Array
// ************************************************************
// Calculate Average
double Average_Value_Sum = 0, Average = 0;
for (int i = 0; i < Read_Count; i++) Average_Value_Sum += Measurement_Array[i];
Average = Average_Value_Sum / Read_Count;
// Calculate Average
Value_ = Average;
// Set Deviation Variable
Deviation_ = 0;
} // Aritmetic Average
if (AVG_Type == 2) {
// ************************************************************
// Calculate RMS Average With Measurement Array
// ************************************************************
// Calculate Average
double Average_Value_Sum = 0, Average = 0;
for (int i = 0; i < Read_Count; i++) Average_Value_Sum += sq(Measurement_Array[i]);
Average = sqrt(Average_Value_Sum / Read_Count);
// Calculate Average
Value_ = Average;
// Set Deviation Variable
Deviation_ = 0;
} // RMS Average
if (AVG_Type == 3) {
// ************************************************************
// Calculate Max & Min values and Extract From Measurement
// Calculate RMS Average With Filtered Measurement Array
// ************************************************************
} // Filtered RMS Average
if (AVG_Type == 4) {
// ************************************************************
// Calculate Median Point of Measurement Array
// ************************************************************
} // Median Average
if (AVG_Type == 5) {
// ************************************************************
// Calculate Average and Standart Deviation With Measurement Array
// Select x Sigma Valid Data and Calculate Aritmetic Average
// ************************************************************
// Define Sigma
float Sigma = 1;
// Define Variables
int Valid_Data_Count = 0;
double Value_Sum = 0;
// Calculate Average
double Average_Value_Sum = 0, Average = 0;
for (int i = 0; i < Read_Count; i++) Average_Value_Sum += Measurement_Array[i];
Average = Average_Value_Sum / Read_Count;
// Calculate Standart Deviation
double Deviation_Value_Sum = 0, Deviation = 0;
for (int i = 0; i < Read_Count; i++) Deviation_Value_Sum += ((Measurement_Array[i] - Average) * (Measurement_Array[i] - Average));
Deviation = sqrt(Deviation_Value_Sum / Read_Count);
// Set Sigma Min/Max Values
float Sigma_1_Max = Average + (Sigma * Deviation);
float Sigma_1_Min = Average - (Sigma * Deviation);
// Handle Array Values
for (int Calculation_ID = 0; Calculation_ID < Read_Count; Calculation_ID++) {
// Control for 1 Sigma Data
if (Measurement_Array[Calculation_ID] >= Sigma_1_Min and Measurement_Array[Calculation_ID] <= Sigma_1_Max) {
// Calculate Sum
Value_Sum += Measurement_Array[Calculation_ID];
// Calculate Valid Data Count
Valid_Data_Count++;
}
}
// Control for Valid Data
if (Valid_Data_Count < 1) {
// Set Error Code
Value_ = -105;
// End Function
return(false);
}
// Calculate Average
Value_ = (Value_Sum / Valid_Data_Count);
// Set Deviation Variable
Deviation_ = Deviation;
} // 1 Sigma Average
// ************************************************************
// Control For Sensor Range
// ************************************************************
if (Value_ < SHT21[0].Range_Min or Value_ > SHT21[0].Range_Max) {
// Set Error Code
Value_ = -106;
// End Function
return(false);
}
// End Function
return(true);
}