BME280Sensor.cpp2113571509349619797.tmp

#include "BME280Sensor.h"
#include <Arduino.h>
#include <stdint.h>
#include "Wire.h"


BME280Sensor::BME280Sensor(): address(0), name("uninitialised"), temperature(0), humidity(0), lastPolled(0){
  
}


BME280Sensor::BME280Sensor(uint8_t address, String name): address(address), name(name), temperature(0), humidity(0), lastPolled(0){
    delay(500);
    uint8_t osrs_t = 1;             //Temperature oversampling x 1
    uint8_t osrs_p = 1;             //Pressure oversampling x 1
    uint8_t osrs_h = 1;             //Humidity oversampling x 1
    uint8_t mode = 3;               //Normal mode
    uint8_t t_sb = 5;               //Tstandby 1000ms
    uint8_t filter = 0;             //Filter off 
    uint8_t spi3w_en = 0;           //3-wire SPI Disable
    
    uint8_t ctrl_meas_reg = (osrs_t << 5) | (osrs_p << 2) | mode;
    uint8_t config_reg    = (t_sb << 5) | (filter << 2) | spi3w_en;
    uint8_t ctrl_hum_reg  = osrs_h;

    writeReg(0xF2,ctrl_hum_reg, address);
    writeReg(0xF4,ctrl_meas_reg, address);
    writeReg(0xF5,config_reg, address);
    readTrim(address);
}


void BME280Sensor::pollSensor() {
  //Serial.print("Polling sensor ");
  //Serial.print(this->address);
  //Serial.print("\n"); //debug
  readData(address);
  this->temperature = calibration_T(temp_raw) / 100.0;
  this->humidity = calibration_H(hum_raw) / 1024.0;
	lastPolled = millis();
}

String BME280Sensor::getName() {
  return name;
}


double BME280Sensor::getTemperature() {
	if (millis() - lastPolled > 1000 ||
	    millis() < lastPolled) {
		pollSensor();
	}
  //Serial.print("Temp is ");
  //Serial.print(temperature);
  //Serial.print("\n"); //debug
	return temperature;
}


double BME280Sensor::getHumidity() {
	if (millis() - lastPolled > 1000 ||
	    millis() < lastPolled) {
		pollSensor();
	}
  //Serial.print("Humidity is ");
  //Serial.print(humidity);
  //Serial.print("\n"); //debug
	return humidity;
}


double BME280Sensor::get(char parameter) {
  switch(parameter) {
  case 'T':
    return getTemperature();
  case 'H':
    return getHumidity();
  }
  return 0.0;
}


void BME280Sensor::readTrim(uint8_t sensorAddress)
{
    uint8_t data[32],i=0;                      // Fix 2014/04/06
    Wire.beginTransmission(sensorAddress);
    Wire.write(0x88);
    Wire.endTransmission();
    Wire.requestFrom(sensorAddress,24);       // Fix 2014/04/06
    while(Wire.available()){
        data[i] = Wire.read();
        i++;
    }
    
    Wire.beginTransmission(sensorAddress);    // Add 2014/04/06
    Wire.write(0xA1);                          // Add 2014/04/06
    Wire.endTransmission();                    // Add 2014/04/06
    Wire.requestFrom(sensorAddress,1);        // Add 2014/04/06
    data[i] = Wire.read();                     // Add 2014/04/06
    i++;                                       // Add 2014/04/06
    
    Wire.beginTransmission(sensorAddress);
    Wire.write(0xE1);
    Wire.endTransmission();
    Wire.requestFrom(sensorAddress,7);        // Fix 2014/04/06
    while(Wire.available()){
        data[i] = Wire.read();
        i++;    
    }
    dig_T1 = (data[1] << 8) | data[0];
    dig_T2 = (data[3] << 8) | data[2];
    dig_T3 = (data[5] << 8) | data[4];
    dig_P1 = (data[7] << 8) | data[6];
    dig_P2 = (data[9] << 8) | data[8];
    dig_P3 = (data[11]<< 8) | data[10];
    dig_P4 = (data[13]<< 8) | data[12];
    dig_P5 = (data[15]<< 8) | data[14];
    dig_P6 = (data[17]<< 8) | data[16];
    dig_P7 = (data[19]<< 8) | data[18];
    dig_P8 = (data[21]<< 8) | data[20];
    dig_P9 = (data[23]<< 8) | data[22];
    dig_H1 = data[24];
    dig_H2 = (data[26]<< 8) | data[25];
    dig_H3 = data[27];
    dig_H4 = (data[28]<< 4) | (0x0F & data[29]);
    dig_H5 = (data[30] << 4) | ((data[29] >> 4) & 0x0F); // Fix 2014/04/06
    dig_H6 = data[31];                                   // Fix 2014/04/06
}


void BME280Sensor::writeReg(uint8_t reg_address, uint8_t data, uint8_t sensorAddress)
{
    Wire.beginTransmission(sensorAddress);
    Wire.write(reg_address);
    Wire.write(data);
    Wire.endTransmission();    
}


void BME280Sensor::readData(uint8_t sensorAddress)
{
    int i = 0;
    uint32_t data[8];
    Wire.beginTransmission(sensorAddress);
    Wire.write(0xF7);
    Wire.endTransmission();
    Wire.requestFrom(sensorAddress,8);
    while(Wire.available()){
        data[i] = Wire.read();
        i++;
    }
    pres_raw = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
    temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
    hum_raw  = (data[6] << 8) | data[7];
}


signed long int BME280Sensor::calibration_T(signed long int adc_T)
{
    
    signed long int var1, var2, T;
    var1 = ((((adc_T >> 3) - ((signed long int)dig_T1<<1))) * ((signed long int)dig_T2)) >> 11;
    var2 = (((((adc_T >> 4) - ((signed long int)dig_T1)) * ((adc_T>>4) - ((signed long int)dig_T1))) >> 12) * ((signed long int)dig_T3)) >> 14;
    
    t_fine = var1 + var2;
    T = (t_fine * 5 + 128) >> 8;
    return T; 
}


unsigned long int BME280Sensor::calibration_P(signed long int adc_P)
{
    signed long int var1, var2;
    unsigned long int P;
    var1 = (((signed long int)t_fine)>>1) - (signed long int)64000;
    var2 = (((var1>>2) * (var1>>2)) >> 11) * ((signed long int)dig_P6);
    var2 = var2 + ((var1*((signed long int)dig_P5))<<1);
    var2 = (var2>>2)+(((signed long int)dig_P4)<<16);
    var1 = (((dig_P3 * (((var1>>2)*(var1>>2)) >> 13)) >>3) + ((((signed long int)dig_P2) * var1)>>1))>>18;
    var1 = ((((32768+var1))*((signed long int)dig_P1))>>15);
    if (var1 == 0)
    {
        return 0;
    }    
    P = (((unsigned long int)(((signed long int)1048576)-adc_P)-(var2>>12)))*3125;
    if(P<0x80000000)
    {
       P = (P << 1) / ((unsigned long int) var1);   
    }
    else
    {
        P = (P / (unsigned long int)var1) * 2;    
    }
    var1 = (((signed long int)dig_P9) * ((signed long int)(((P>>3) * (P>>3))>>13)))>>12;
    var2 = (((signed long int)(P>>2)) * ((signed long int)dig_P8))>>13;
    P = (unsigned long int)((signed long int)P + ((var1 + var2 + dig_P7) >> 4));
    return P;
}


unsigned long int BME280Sensor::calibration_H(signed long int adc_H)
{
    signed long int v_x1;
    
    v_x1 = (t_fine - ((signed long int)76800));
    v_x1 = (((((adc_H << 14) -(((signed long int)dig_H4) << 20) - (((signed long int)dig_H5) * v_x1)) + 
              ((signed long int)16384)) >> 15) * (((((((v_x1 * ((signed long int)dig_H6)) >> 10) * 
              (((v_x1 * ((signed long int)dig_H3)) >> 11) + ((signed long int) 32768))) >> 10) + (( signed long int)2097152)) * 
              ((signed long int) dig_H2) + 8192) >> 14));
   v_x1 = (v_x1 - (((((v_x1 >> 15) * (v_x1 >> 15)) >> 7) * ((signed long int)dig_H1)) >> 4));
   v_x1 = (v_x1 < 0 ? 0 : v_x1);
   v_x1 = (v_x1 > 419430400 ? 419430400 : v_x1);
   return (unsigned long int)(v_x1 >> 12);   
}