Sensor - BME280 - Temperatuur, Luchtvochtigheid en Barometrische druk sensor

Hardware

Informatie (ENG)

Description:
The BME280 Breakout Board is the easy way to measure pressure and humidity, and without taking up a lot of room. It gives you easy to solder 0.1″ headers, runs I2C or SPI, takes measurements at less than 1mA and idles less than 5uA (yes, microamps!).
The BME280 can be used to take pressure, humidity, and temperature readings. Use the data to get relative altitude changes, or absolute altitude if the locally reported barometric pressure is known.

Specificaties:
Temp: -40C to 85C
Humidity: 0 – 100% RH, =-3% from 20-80%
Pressure: 30,000Pa to 110,000Pa, relative accuracy of 12Pa, absolute accuracy of 100Pa
Altitude: 0 to 30,000 ft (9.2 km), relative accuracy of 3.3 ft (1 m) at sea level, 6.6 (2 m) at 30,000 ft.

Typical application:
– Enhancement of GPS navigation (e.g. time-to-first-fix improvement,dead-reckoning,slope detection)
– Indoor navigation (floor detection,elevator detection)
– Outdoor navigation,leisure and sports applications
– Weather forecast
– Health care application (e.g. sirometry)
– Vertical velocity indication (e.g. risk/sink speed)

Mini module – change address

To change the I2C address from 0x76 to 0x77:

Pinout

Pin:	Functie:
1	+5V (VCC)
2	GND
3	SCL Serial Clock (line)
4	SCA Serial Clock (data)
5	CSB (Chip Select)
6	SDO (Serial Data Out)

Arduino

Sluit de module aan volgens onderstaand overzicht:

Arduino pin:	BMP280 pin:
+5V	+5V (VCC)
GND	GND
A5	SCL Serial Clock (line)
A4	SCA Serial Clock (data)

Script met BME280 bibliotheek

Wat heb je nodig?

1) BME280 bibliotheek

Het script leest de Temperatuur, Luchtvochtigheid en Luchtdruk uit:

#include <BME280I2C.h>
#include <Wire.h>

#define SERIAL_BAUD 9600

BME280I2C bme;    // Default : forced mode, standby time = 1000 ms
                  // Oversampling = pressure ×1, temperature ×1, humidity ×1, filter off,

float pres, temp, hum;

void setup(){
  Serial.begin(SERIAL_BAUD);
  while(!Serial) {} // Wait

  Wire.begin();
  while(!bme.begin()) { Serial.println("Could not find BME280 sensor!"); delay(1000); }
}

void loop() {
   BME280::TempUnit tempUnit(BME280::TempUnit_Celsius);
   BME280::PresUnit presUnit(BME280::PresUnit_Pa);

   bme.read(pres, temp, hum, tempUnit, presUnit);

   Serial.print("\tTemp: "); Serial.print(temp); Serial.print("C");
   Serial.print("\tHum: "); Serial.print(hum); Serial.print("% RH");
   Serial.print("\tPres: "); Serial.print(pres); Serial.println(" Pa");
   delay(1000);
}

#include <BME280I2C.h>

#include <Wire.h>

#define SERIAL_BAUD 9600

BME280I2C bme; // Default : forced mode, standby time = 1000 ms

// Oversampling = pressure ×1, temperature ×1, humidity ×1, filter off,

float pres, temp, hum;

void setup(){

Serial.begin(SERIAL_BAUD);

while(!Serial) {} // Wait

Wire.begin();

while(!bme.begin()) { Serial.println("Could not find BME280 sensor!"); delay(1000); }

}

void loop() {

BME280::TempUnit tempUnit(BME280::TempUnit_Celsius);

BME280::PresUnit presUnit(BME280::PresUnit_Pa);

bme.read(pres, temp, hum, tempUnit, presUnit);

Serial.print("\tTemp: "); Serial.print(temp); Serial.print("C");

Serial.print("\tHum: "); Serial.print(hum); Serial.print("% RH");

Serial.print("\tPres: "); Serial.print(pres); Serial.println(" Pa");

delay(1000);

}

Het resultaat

Temp: 24.50C	Hum: 32.08% RH	Pres: 100314.98 Pa
Temp: 24.45C	Hum: 32.15% RH	Pres: 100317.16 Pa
Temp: 24.45C	Hum: 32.16% RH	Pres: 100312.70 Pa
Temp: 24.44C	Hum: 32.15% RH	Pres: 100315.46 Pa
Temp: 24.44C	Hum: 32.17% RH	Pres: 100313.67 Pa
Temp: 24.45C	Hum: 32.21% RH	Pres: 100312.70 Pa
Temp: 24.43C	Hum: 32.30% RH	Pres: 100311.98 Pa
Temp: 24.43C	Hum: 32.47% RH	Pres: 100314.63 Pa
Temp: 24.42C	Hum: 32.59% RH	Pres: 100307.70 Pa
Temp: 24.43C	Hum: 32.60% RH	Pres: 100314.63 Pa
Temp: 24.42C	Hum: 32.54% RH	Pres: 100309.48 Pa

Temp: 24.50C Hum: 32.08% RH Pres: 100314.98 Pa

Temp: 24.45C Hum: 32.15% RH Pres: 100317.16 Pa

Temp: 24.45C Hum: 32.16% RH Pres: 100312.70 Pa

Temp: 24.44C Hum: 32.15% RH Pres: 100315.46 Pa

Temp: 24.44C Hum: 32.17% RH Pres: 100313.67 Pa

Temp: 24.45C Hum: 32.21% RH Pres: 100312.70 Pa

Temp: 24.43C Hum: 32.30% RH Pres: 100311.98 Pa

Temp: 24.43C Hum: 32.47% RH Pres: 100314.63 Pa

Temp: 24.42C Hum: 32.59% RH Pres: 100307.70 Pa

Temp: 24.43C Hum: 32.60% RH Pres: 100314.63 Pa

Temp: 24.42C Hum: 32.54% RH Pres: 100309.48 Pa

Script met alleen wire bibliotheek

Wat heb je nodig?

1) Alleen de Wire bibliotheek (wordt standaard bijgeleverd bij ArduinoIDE)

Het standaard adres is 0x76, pas deze regel aan indien een afwijkend adres is gebruikt:

#define BME280_ADDRESS 0x76

Het script leest de Temperatuur, Luchtvochtigheid en Luchtdruk uit:

#include <Wire.h>

#define BME280_ADDRESS 0x76

unsigned long int hum_raw,temp_raw,pres_raw;
signed long int t_fine;
uint16_t dig_T1;
int16_t dig_T2;
int16_t dig_T3;
uint16_t dig_P1;
int16_t dig_P2;
int16_t dig_P3;
int16_t dig_P4;
int16_t dig_P5;
int16_t dig_P6;
int16_t dig_P7;
int16_t dig_P8;
int16_t dig_P9;
int8_t  dig_H1;
int16_t dig_H2;
int8_t  dig_H3;
int16_t dig_H4;
int16_t dig_H5;
int8_t  dig_H6;
void setup() {
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;
Serial.begin(9600);
Wire.begin();
writeReg(0xF2,ctrl_hum_reg);
writeReg(0xF4,ctrl_meas_reg);
writeReg(0xF5,config_reg);
readTrim();                    //
}

void loop() {
double temp_act = 0.0, press_act = 0.0,hum_act=0.0;
signed long int temp_cal;
unsigned long int press_cal,hum_cal;
readData();
temp_cal = calibration_T(temp_raw);
press_cal = calibration_P(pres_raw);
hum_cal = calibration_H(hum_raw);
temp_act = (double)temp_cal / 100.0;
press_act = (double)press_cal / 100.0;
hum_act = (double)hum_cal / 1024.0;
Serial.print("TEMP : ");
Serial.print(temp_act);
Serial.print(" DegC  PRESS : ");
Serial.print(press_act);
Serial.print(" hPa  HUM : ");
Serial.print(hum_act);
Serial.println(" %");
delay(1000);
}

void readTrim() {
uint8_t data[32],i=0;
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0x88);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,24);

while(Wire.available()) {
  data[i] = Wire.read();
  i++;
}

Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xA1);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,1);
data[i] = Wire.read();
i++;
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xE1);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,7);

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);
dig_H6 = data[31];
}

void writeReg(uint8_t reg_address, uint8_t data) {
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(reg_address);
Wire.write(data);
Wire.endTransmission();
}

void readData() {
int i = 0;
uint32_t data[8];
Wire.beginTransmission(BME280_ADDRESS);
Wire.write(0xF7);
Wire.endTransmission();
Wire.requestFrom(BME280_ADDRESS,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 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 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 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);
}

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#include <Wire.h>

#define BME280_ADDRESS 0x76

unsigned long int hum_raw,temp_raw,pres_raw;

signed long int t_fine;

uint16_t dig_T1;

int16_t dig_T2;

int16_t dig_T3;

uint16_t dig_P1;

int16_t dig_P2;

int16_t dig_P3;

int16_t dig_P4;

int16_t dig_P5;

int16_t dig_P6;

int16_t dig_P7;

int16_t dig_P8;

int16_t dig_P9;

int8_t dig_H1;

int16_t dig_H2;

int8_t dig_H3;

int16_t dig_H4;

int16_t dig_H5;

int8_t dig_H6;

void setup() {

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;

Serial.begin(9600);

Wire.begin();

writeReg(0xF2,ctrl_hum_reg);

writeReg(0xF4,ctrl_meas_reg);

writeReg(0xF5,config_reg);

readTrim(); //

}

void loop() {

double temp_act = 0.0, press_act = 0.0,hum_act=0.0;

signed long int temp_cal;

unsigned long int press_cal,hum_cal;

readData();

temp_cal = calibration_T(temp_raw);

press_cal = calibration_P(pres_raw);

hum_cal = calibration_H(hum_raw);

temp_act = (double)temp_cal / 100.0;

press_act = (double)press_cal / 100.0;

hum_act = (double)hum_cal / 1024.0;

Serial.print("TEMP : ");

Serial.print(temp_act);

Serial.print(" DegC PRESS : ");

Serial.print(press_act);

Serial.print(" hPa HUM : ");

Serial.print(hum_act);

Serial.println(" %");

delay(1000);

}

void readTrim() {

uint8_t data[32],i=0;

Wire.beginTransmission(BME280_ADDRESS);

Wire.write(0x88);

Wire.endTransmission();

Wire.requestFrom(BME280_ADDRESS,24);

while(Wire.available()) {

data[i] = Wire.read();

i++;

}

Wire.beginTransmission(BME280_ADDRESS);

Wire.write(0xA1);

Wire.endTransmission();

Wire.requestFrom(BME280_ADDRESS,1);

data[i] = Wire.read();

i++;

Wire.beginTransmission(BME280_ADDRESS);

Wire.write(0xE1);

Wire.endTransmission();

Wire.requestFrom(BME280_ADDRESS,7);

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);

dig_H6 = data[31];

}

void writeReg(uint8_t reg_address, uint8_t data) {

Wire.beginTransmission(BME280_ADDRESS);

Wire.write(reg_address);

Wire.write(data);

Wire.endTransmission();

}

void readData() {

int i = 0;

uint32_t data[8];

Wire.beginTransmission(BME280_ADDRESS);

Wire.write(0xF7);

Wire.endTransmission();

Wire.requestFrom(BME280_ADDRESS,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 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 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 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);

}

Het resultaat

TEMP : 25.54 DegC  PRESS : 1019.16 hPa  HUM : 47.29 %
TEMP : 25.51 DegC  PRESS : 1019.19 hPa  HUM : 47.31 %
TEMP : 25.51 DegC  PRESS : 1019.24 hPa  HUM : 47.32 %
TEMP : 26.66 DegC  PRESS : 1019.18 hPa  HUM : 50.57 %
TEMP : 27.47 DegC  PRESS : 1019.16 hPa  HUM : 50.83 %
TEMP : 27.75 DegC  PRESS : 1019.17 hPa  HUM : 51.09 %
TEMP : 27.89 DegC  PRESS : 1019.20 hPa  HUM : 51.41 %
TEMP : 28.04 DegC  PRESS : 1019.18 hPa  HUM : 51.69 %
TEMP : 27.39 DegC  PRESS : 1019.13 hPa  HUM : 53.10 %
TEMP : 26.75 DegC  PRESS : 1019.18 hPa  HUM : 50.68 %
TEMP : 26.50 DegC  PRESS : 1019.12 hPa  HUM : 49.25 %

TEMP : 25.54 DegC PRESS : 1019.16 hPa HUM : 47.29 %

TEMP : 25.51 DegC PRESS : 1019.19 hPa HUM : 47.31 %

TEMP : 25.51 DegC PRESS : 1019.24 hPa HUM : 47.32 %

TEMP : 26.66 DegC PRESS : 1019.18 hPa HUM : 50.57 %

TEMP : 27.47 DegC PRESS : 1019.16 hPa HUM : 50.83 %

TEMP : 27.75 DegC PRESS : 1019.17 hPa HUM : 51.09 %

TEMP : 27.89 DegC PRESS : 1019.20 hPa HUM : 51.41 %

TEMP : 28.04 DegC PRESS : 1019.18 hPa HUM : 51.69 %

TEMP : 27.39 DegC PRESS : 1019.13 hPa HUM : 53.10 %

TEMP : 26.75 DegC PRESS : 1019.18 hPa HUM : 50.68 %

TEMP : 26.50 DegC PRESS : 1019.12 hPa HUM : 49.25 %

Bronnen:
osoyoo.com

Script met BME280 bibliotheek op SPI

Wat heb je nodig?

1) BME280 bibliotheek

Sluit de BME280 module aan op de arduino aan zoals hieronder aangegeven:

Het script leest de Temperatuur, Luchtvochtigheid en Luchtdruk uit:

#include <SPI.h> 
#include <BME280Spi.h>

#define DEVICE_PIN 10

BME280Spi::Settings settings(DEVICE_PIN); // Default : forced mode, standby time = 1000 ms
                                          //           Oversampling = pressure ×1, temperature ×1, humidity ×1, filter off,
BME280Spi bme(settings);

void setup() {
   Serial.begin(115200);
   while(!Serial) {} // Wait

   SPI.begin();
   while(!bme.begin()) {
      Serial.println("Could not find BME280 sensor!");
      delay(1000);
   }
}

void loop() {
   printBME280Data(&Serial);
   delay(500);
}

void printBME280Data (Stream* client) {
   float temp(NAN), hum(NAN), pres(NAN);

   BME280::TempUnit tempUnit(BME280::TempUnit_Celsius);
   BME280::PresUnit presUnit(BME280::PresUnit_Pa);

   bme.read(pres, temp, hum, tempUnit, presUnit);

   client->print("Temp: ");
   client->print(temp);
   client->print("°"+ String(tempUnit == BME280::TempUnit_Celsius ? 'C' :'F'));
   client->print("\t\tHumidity: ");
   client->print(hum);
   client->print("% RH");
   client->print("\t\tPressure: ");
   client->print(pres);
   client->println("Pa");

   delay(1000);
}

#include <SPI.h>

#include <BME280Spi.h>

#define DEVICE_PIN 10

BME280Spi::Settings settings(DEVICE_PIN); // Default : forced mode, standby time = 1000 ms

// Oversampling = pressure ×1, temperature ×1, humidity ×1, filter off,

BME280Spi bme(settings);

void setup() {

Serial.begin(115200);

while(!Serial) {} // Wait

SPI.begin();

while(!bme.begin()) {

Serial.println("Could not find BME280 sensor!");

delay(1000);

}

void loop() {

printBME280Data(&Serial);

delay(500);

}

void printBME280Data (Stream* client) {

float temp(NAN), hum(NAN), pres(NAN);

BME280::TempUnit tempUnit(BME280::TempUnit_Celsius);

BME280::PresUnit presUnit(BME280::PresUnit_Pa);

bme.read(pres, temp, hum, tempUnit, presUnit);

client->print("Temp: ");

client->print(temp);

client->print("°"+ String(tempUnit == BME280::TempUnit_Celsius ? 'C' :'F'));

client->print("\t\tHumidity: ");

client->print(hum);

client->print("% RH");

client->print("\t\tPressure: ");

client->print(pres);

client->println("Pa");

delay(1000);

}

Temp: 27.53oC		Humidity: 37.72% RH		Pressure: 102430.53Pa
Temp: 27.49oC		Humidity: 37.77% RH		Pressure: 102431.69Pa
Temp: 27.51oC		Humidity: 37.76% RH		Pressure: 102427.92Pa
Temp: 27.53oC		Humidity: 37.71% RH		Pressure: 102427.85Pa
Temp: 27.53oC		Humidity: 37.70% RH		Pressure: 102432.36Pa

Temp: 27.53oC Humidity: 37.72% RH Pressure: 102430.53Pa

Temp: 27.49oC Humidity: 37.77% RH Pressure: 102431.69Pa

Temp: 27.51oC Humidity: 37.76% RH Pressure: 102427.92Pa

Temp: 27.53oC Humidity: 37.71% RH Pressure: 102427.85Pa

Temp: 27.53oC Humidity: 37.70% RH Pressure: 102432.36Pa

Arduino Library

Installatie van Arduino IDE libraries: Arduino info

BME280 Library

Informatie (ENG)

Summary

Reads temperature, humidity, and pressure. Calculates altitude, equivalent sea level pressure and dew point. Provides functions for english and metric. Also reads pressure in Pa, hPa, inHg, atm, bar, torr, N/m^2 and psi.

Installation

To use this library download the zip file, decompress it to a folder named BME280. Move the folder to {Arduino Path}/libraries.

Usage

Include the library at the top of your Arduino script. #include <BME280> Create a global or local variable. BME280 bme In your start up call bme.begin(). Read the temperature, humidity, pressure, altitude and/or dew point.

float pres, temp, hum bme.read(pres, temp, hum)

temp = bme.temp() hum = bme.hum() pres = bme.pres()

Enumerations

TempUnit Enum

TempUnit_Celsius
TempUnit_Fahrenheit

PresUnit Enum

PresUnit_Pa
PresUnit_hPa
PresUnit_inHg
PresUnit_atm
PresUnit_bar
PresUnit_torr
PresUnit_psi

OSR Enum

OSR_Off
OSR_X1
OSR_X2
OSR_X4
OSR_X8
OSR_X16

Mode Enum

Mode_Sleep
Mode_Forced
Mode_Normal

StandbyTime Enum

StandbyTime_500us
StandbyTime_62500us
StandbyTime_125ms
StandbyTime_250ms
StandbyTime_50ms
StandbyTime_1000ms
StandbyTime_10ms
StandbyTime_20ms

Filter Enum

Filter_Off
Filter_1
Filter_2
Filter_4
Filter_8
Filter_16

ChipModel Enum

ChipModel_Unknown
ChipModel_BME280
ChipModel_BMP280

Settings

BME280::Settings Struct

    * Temperature Oversampling Rate (tempOSR): OSR Enum, default = OSR_X1

    * Humidity Oversampling Rate (humOSR): OSR Enum, default = OSR_X1

    * Pressure Oversampling Rate (presOSR): OSR Enum, default = OSR_X1

    * Mode (mode): Mode Enum, default = Mode_Forced

    * Standby Time (standbyTime): StandbyTime Enum, default = StandbyTime_1000ms

    * Filter (filter): Filter Enum, default = Filter_16

    * SPI Enable: SpiEnable Enum, default = false
      values: true = enable, false = disable

* Temperature Oversampling Rate (tempOSR): OSR Enum, default = OSR_X1

* Humidity Oversampling Rate (humOSR): OSR Enum, default = OSR_X1

* Pressure Oversampling Rate (presOSR): OSR Enum, default = OSR_X1

* Mode (mode): Mode Enum, default = Mode_Forced

* Standby Time (standbyTime): StandbyTime Enum, default = StandbyTime_1000ms

* Filter (filter): Filter Enum, default = Filter_16

* SPI Enable: SpiEnable Enum, default = false

values: true = enable, false = disable

BME280I2C::Settings Struct

Includes all fields in BME280 settings.

   * BME 280 Address (bme280Addr): uint8_t, default = 0x76

1 2	* BME 280 Address (bme280Addr): uint8_t, default = 0x76

BME280Spi::Settings Struct

Includes all fields in BME280 settings.

   * SPI Chip Select Pin (spiCsPin): uint8_t
      values: Any pin 0-31

* SPI Chip Select Pin (spiCsPin): uint8_t

values: Any pin 0-31

BME280Spi::Settings Struct

Includes all fields in BME280 settings.

   * SPI Chip Select Pin (spiCsPin): uint8_t
     values: Any pin 0-31

   * SPI Master Out Slave In Pin (spiMosiPin): uint8_t
     values: Any pin 0-31

   * SPI Master In Slave Out Pin (spiMisoPin): uint8_t
     values: Any pin 0-31

   * SPI Serial Clock Pin (spiSckPin): uint8_t
     values: Any pin 0-31

* SPI Chip Select Pin (spiCsPin): uint8_t

values: Any pin 0-31

* SPI Master Out Slave In Pin (spiMosiPin): uint8_t

values: Any pin 0-31

* SPI Master In Slave Out Pin (spiMisoPin): uint8_t

values: Any pin 0-31

* SPI Serial Clock Pin (spiSckPin): uint8_t

values: Any pin 0-31

Methods

BME280I2C(const BME280I2C::Settings& settings)

Constructor used to create the I2C Bme class. All parameters have default values.

BME280Spi(const BME280Spi::Settings& settings)

Constructor used to create the Spi Bme class. All parameters have default values except chip select.

BME280SpiSw(const BME280SpiSw::Settings& settings)

Constructor used to create the software Spi Bme class. All parameters have default values except chip select, mosi, miso and sck.

bool begin()

Method used at start up to initialize the class. Starts the I2C or SPI interface. Can be called again to re-initialize the mode settings.

  * return: bool, true = success, false = failure (no device found)

1 2	* return: bool, true = success, false = failure (no device found)

void setSettings(const Settings& settings)

Method to set the sensor settings.

const Settings& getSettings() const

Method to get the sensor settings.

float temp(TempUnit unit)

Read the temperature from the BME280 and return a float.

    return: float = temperature

    * unit: tempUnit, default = TempUnit_Celsius

return: float = temperature

* unit: tempUnit, default = TempUnit_Celsius

float pres(PresUnit unit)

Read the pressure from the BME280 and return a float with the specified unit.

    return: float = pressure

    * presUnit: uint8_t, default = PresUnit_hPa

return: float = pressure

* presUnit: uint8_t, default = PresUnit_hPa

float hum()

Read the humidity from the BME280 and return a percentage as a float.

    * return: float = percent relative humidity

1 2	* return: float = percent relative humidity

void read(float& pressure, float& temp, float& humidity, TempUnit tempUnit, PresUnit presUnit)

Read the data from the BME280 with the specified units.

    return: None, however, pressure, temp and humidity are changed.

    * Pressure: float, reference
      values: reference to storage float for pressure

    * Temperature: float, reference
      values: reference to storage float for temperature

    * Humidity: float, reference
      values: reference to storage float for humidity

    * tempUnit: tempUnit, default = TempUnit_Celsius

    * presUnit: uint8_t, default = PresUnit_hPa

return: None, however, pressure, temp and humidity are changed.

* Pressure: float, reference

values: reference to storage float for pressure

* Temperature: float, reference

values: reference to storage float for temperature

* Humidity: float, reference

values: reference to storage float for humidity

* tempUnit: tempUnit, default = TempUnit_Celsius

* presUnit: uint8_t, default = PresUnit_hPa

ChipModel chipModel()

    * return: [ChipModel](#chipmodel-enum) enum

1 2	* return: [ChipModel](#chipmodel-enum) enum

Environment Calculations

float Altitude(float pressure, AltitudeUnit = AltitudeUnit_Meters, float seaLevelPressure = 1013.25, outsideTemp = 15.0, TempUnit = TempUnit_Celsius)

Calculate the altitude based on the pressure with the specified units.

    Return: float altitude

    * Pressure: float
      values: unit independent

    * AltitudeUnit: default = AltitudeUnit_Meters
      values:  AltitudeUnit_Meters, AltitudeUnit_Feet

    * Sea Level Pressure: float, default = 1013.25
      values:  unit independent

    * outsideTemp: float, default = 15.0
      values:  any float related to TempUnit

    * TempUnit: default = TempUnit_Celsius
      values: TempUnit_Celsius, TempUnit_Fahrenheit

      Note: The formula evaluates the height difference based on difference of pressure.
     - May be used to evaluate altitude over MSL. (default set)
                (default referencePressure, default outsideTemp parameters ~ ISA standard)
                The altitude is derived from QNH, used in aviation.
     - May be used to evaluate height over MSL
                (referencePressure should be equal to QFF read in meteorologic synoptic maps,
                outsideTemp should be equal to local temperature)
     - May be used to evaluate the height difference between two points
                (referencePressure should be set to the pressure on the lower point.)

Return: float altitude

* Pressure: float

values: unit independent

* AltitudeUnit: default = AltitudeUnit_Meters

values: AltitudeUnit_Meters, AltitudeUnit_Feet

* Sea Level Pressure: float, default = 1013.25

values: unit independent

* outsideTemp: float, default = 15.0

values: any float related to TempUnit

* TempUnit: default = TempUnit_Celsius

values: TempUnit_Celsius, TempUnit_Fahrenheit

Note: The formula evaluates the height difference based on difference of pressure.

- May be used to evaluate altitude over MSL. (default set)

(default referencePressure, default outsideTemp parameters ~ ISA standard)

The altitude is derived from QNH, used in aviation.

- May be used to evaluate height over MSL

(referencePressure should be equal to QFF read in meteorologic synoptic maps,

outsideTemp should be equal to local temperature)

- May be used to evaluate the height difference between two points

(referencePressure should be set to the pressure on the lower point.)

float EquivalentSeaLevelPressure(float altitude, float temp, float pres, AltitudeUnit altUnit, TempUnit tempUnit )

Convert current pressure to equivalent sea-level pressure.

    Return: float equivalent pressure at sea level.

    * altitude: float
      values: meters

    * temp: float
      values: celsius

    * pres: float
      values: unit independent

    * AltitudeUnit: default = AltitudeUnit_Meters
      values:  AltitudeUnit_Meters, AltitudeUnit_Feet

    * TempUnit: default = TempUnit_Celsius
      values: TempUnit_Celsius, TempUnit_Fahrenheit

      Note: To get correct EquivalentSeaLevel pressure (QNH or QFF) the altitude value should be independent
      on measured pressure. It is necessary to use fixed altitude point e.g. the altitude of barometer
      read in map.

Return: float equivalent pressure at sea level.

* altitude: float

values: meters

* temp: float

values: celsius

* pres: float

values: unit independent

* AltitudeUnit: default = AltitudeUnit_Meters

values: AltitudeUnit_Meters, AltitudeUnit_Feet

* TempUnit: default = TempUnit_Celsius

values: TempUnit_Celsius, TempUnit_Fahrenheit

Note: To get correct EquivalentSeaLevel pressure (QNH or QFF) the altitude value should be independent

on measured pressure. It is necessary to use fixed altitude point e.g. the altitude of barometer

read in map.

float DewPoint(float temp, float hum, TempUnit = TempUnit_Celsius)

Calculate the dew point based on the temperature and humidity with the specified units.

    return: float dew point

    * Temperature: float
      values: any float related to TempUnit

    * Humidity: float, unit = % relative humidity
      values: any float

    * TempUnit: TempUnit, default = TempUnit_Celsius
      values: TempUnit_Celsius = return degrees Celsius, TempUnit_Fahrenheit = return degrees Fahrenheit

return: float dew point

* Temperature: float

values: any float related to TempUnit

* Humidity: float, unit = % relative humidity

values: any float

* TempUnit: TempUnit, default = TempUnit_Celsius

values: TempUnit_Celsius = return degrees Celsius, TempUnit_Fahrenheit = return degrees Fahrenheit

float AbsoluteHumidity(float temperature, float humidity, TempUnit = TempUnit_Celsius)

Calculate the absolute humidity based on the temperature and humidity with the specified units.

    return: float absolute humidity

    * Temperature: float
      values: any float related to TempUnit

    * Humidity: float, unit = % relative humidity
      values: any float

    * TempUnit: TempUnit, default = TempUnit_Celsius
      values: TempUnit_Celsius = return degrees Celsius, TempUnit_Fahrenheit = return degrees Fahrenheit

return: float absolute humidity

* Temperature: float

values: any float related to TempUnit

* Humidity: float, unit = % relative humidity

values: any float

* TempUnit: TempUnit, default = TempUnit_Celsius

values: TempUnit_Celsius = return degrees Celsius, TempUnit_Fahrenheit = return degrees Fahrenheit

int HeatIndex(float temperature, float humidity, TempUnit tempUnit = TempUnit_Celsius)

Calculate the heat index based on the temperature and humidity with the specified units. The heat index is only calculated if the temperature is above 26.7°C or 80°F and humidity above 40%. The precision is +/- 0.7°C / 1.3°F.

    return: int heat index

    * Temperature: float
      values: any float related to TempUnit

    * Humidity: float, unit = % relative humidity
      values: any float

    * TempUnit: TempUnit, default = TempUnit_Celsius
      values: TempUnit_Celsius = return degrees Celsius, TempUnit_Fahrenheit = return degrees Fahrenheit

return: int heat index

* Temperature: float

values: any float related to TempUnit

* Humidity: float, unit = % relative humidity

values: any float

* TempUnit: TempUnit, default = TempUnit_Celsius

values: TempUnit_Celsius = return degrees Celsius, TempUnit_Fahrenheit = return degrees Fahrenheit

History

Jan 1, 2016 – Version 1.0.0 released
Sep 19, 2016 – Version 2.0.0 released (Restructure for I2C and SPI)
Nov 21, 2016 – Version 2.0.1 released (Set mode support)
Dec 19, 2016 – Version 2.1.0 released (Support for SPI)
Dec 21, 2016 – Version 2.1.1 released (Bugs)
Feb 17, 2017 – Version 2.1.2 released (Docs)
Sept 9, 2017 – Version 2.1.3 released (Formatting, reorg)
Sept 13, 2017 – Version 2.1.4 released (Examples update, bug fixes)
Oct 7, 2017 – Version 2.2.0 released (Enums, begin restructure)
Oct 10, 2017 – Version 2.2.1 released (Bug fixes)

Download bibliotheek @ finitespace * Github

BME280-Release_Version_2.3.0.7z 22,29 kb
BME280-Release_Version_2.2.1.7z 21,95 kb
BME280-Release_Version_2.1.4.7z 21,28 kb
BME280-Release_Version_2.1.3.7z 21,41 kb
BME280-Release_Version_2.1.2.7z 19,85 kb
BME280-Release_Version_2.1.01.7z 19,77 kb
BME280-Release_Version_2.0.1.7z 20,97 kb
BME280-Release_Version_2.0.01.7z 18,25 kb
BME280-Release_Version_2.0.0.7z 18,06 kb
BME280-Release_Version_1.0.02.7z 17,65 kb
BME280-Release_Version_1.0.01.7z 17,63 kb
BME280-Release_Version_1.0.0.7z 17,61 kb

Raspberry Pi

Sluit de module aan zoals aangegeven op onderstaand schema:

Raspberry Pi pin:	I2C module pin:
+5v	+5v
GND	GND
3 (GPIO2) SDA	SDA
5 (GPIO3) SCL	SCL

Ps. Altijd de pinout van je Raspberry Pi controleren, deze kan verschillen per versie.

Wat moet je doen?

1) I2C aanzetten op de Pi.
2) SMBUS module installeren voor Python:

Om de I²C bus in Python te gebruiken moet je een module installeren, genaamd SMBUS, dit kan via APT-GET met het commando: sudo apt-get install python-smbus

Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
  python-smbus
0 upgraded, 1 newly installed, 0 to remove and 79 not upgraded.
Need to get 11.9 kB of archives.
After this operation, 95.2 kB of additional disk space will be used.
Get:1 http://archive.raspberrypi.org/debian/ wheezy/main python-smbus armhf 3.1.1+svn-1 [11.9 kB]
Fetched 11.9 kB in 0s (131 kB/s)
Selecting previously unselected package python-smbus.
(Reading database ... 78301 files and directories currently installed.)
Unpacking python-smbus (from .../python-smbus_3.1.1+svn-1_armhf.deb) ...
Setting up python-smbus (3.1.1+svn-1) ...

Reading package lists... Done

Building dependency tree

Reading state information... Done

The following NEW packages will be installed:

python-smbus

0 upgraded, 1 newly installed, 0 to remove and 79 not upgraded.

Need to get 11.9 kB of archives.

After this operation, 95.2 kB of additional disk space will be used.

Get:1 http://archive.raspberrypi.org/debian/ wheezy/main python-smbus armhf 3.1.1+svn-1 [11.9 kB]

Fetched 11.9 kB in 0s (131 kB/s)

Selecting previously unselected package python-smbus.

(Reading database ... 78301 files and directories currently installed.)

Unpacking python-smbus (from .../python-smbus_3.1.1+svn-1_armhf.deb) ...

Setting up python-smbus (3.1.1+svn-1) ...

Je kan dan de module importeren in python door middel van: import smbus

Controleren van de aansluiting

Om de aansluiting van de module te controleren voor je het volgende commando uit: sudo i2cdetect -y 1, je ziet dan adres 0x77 staan in de lijst:

pi@raspberrypi:~ $ sudo i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:          -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- 76 --

pi@raspberrypi:~ $ sudo i2cdetect -y 1

0 1 2 3 4 5 6 7 8 9 a b c d e f

00: -- -- -- -- -- -- -- -- -- -- -- -- --

10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --

70: -- -- -- -- -- -- 76 --

Het script bme280.py om de module uit te lezen:

import smbus
import time

# Get I2C bus
bus = smbus.SMBus(1)

# BME280 address, 0x76(118)
# Read data back from 0x88(136), 24 bytes
b1 = bus.read_i2c_block_data(0x76, 0x88, 24)

# Convert the data
# Temp coefficients
dig_T1 = b1[1] * 256 + b1[0]
dig_T2 = b1[3] * 256 + b1[2]
if dig_T2 > 32767 :
    dig_T2 -= 65536
dig_T3 = b1[5] * 256 + b1[4]
if dig_T3 > 32767 :
    dig_T3 -= 65536

# Pressure coefficients
dig_P1 = b1[7] * 256 + b1[6]
dig_P2 = b1[9] * 256 + b1[8]
if dig_P2 > 32767 :
    dig_P2 -= 65536
dig_P3 = b1[11] * 256 + b1[10]
if dig_P3 > 32767 :
    dig_P3 -= 65536
dig_P4 = b1[13] * 256 + b1[12]
if dig_P4 > 32767 :
    dig_P4 -= 65536
dig_P5 = b1[15] * 256 + b1[14]
if dig_P5 > 32767 :
    dig_P5 -= 65536
dig_P6 = b1[17] * 256 + b1[16]
if dig_P6 > 32767 :
    dig_P6 -= 65536
dig_P7 = b1[19] * 256 + b1[18]
if dig_P7 > 32767 :
    dig_P7 -= 65536
dig_P8 = b1[21] * 256 + b1[20]
if dig_P8 > 32767 :
    dig_P8 -= 65536
dig_P9 = b1[23] * 256 + b1[22]
if dig_P9 > 32767 :
    dig_P9 -= 65536

# BME280 address, 0x76(118)
# Read data back from 0xA1(161), 1 byte
dig_H1 = bus.read_byte_data(0x76, 0xA1)

# BME280 address, 0x76(118)
# Read data back from 0xE1(225), 7 bytes
b1 = bus.read_i2c_block_data(0x76, 0xE1, 7)

# Convert the data
# Humidity coefficients
dig_H2 = b1[1] * 256 + b1[0]
if dig_H2 > 32767 :
    dig_H2 -= 65536
dig_H3 = (b1[2] &  0xFF)
dig_H4 = (b1[3] * 16) + (b1[4] & 0xF)
if dig_H4 > 32767 :
    dig_H4 -= 65536
dig_H5 = (b1[4] / 16) + (b1[5] * 16)
if dig_H5 > 32767 :
    dig_H5 -= 65536
dig_H6 = b1[6]
if dig_H6 > 127 :
    dig_H6 -= 256

# BME280 address, 0x76(118)
# Select control humidity register, 0xF2(242)
#		0x01(01)	Humidity Oversampling = 1
bus.write_byte_data(0x76, 0xF2, 0x01)
# BME280 address, 0x76(118)
# Select Control measurement register, 0xF4(244)
#		0x27(39)	Pressure and Temperature Oversampling rate = 1
#					Normal mode
bus.write_byte_data(0x76, 0xF4, 0x27)
# BME280 address, 0x76(118)
# Select Configuration register, 0xF5(245)
#		0xA0(00)	Stand_by time = 1000 ms
bus.write_byte_data(0x76, 0xF5, 0xA0)

time.sleep(0.5)

# BME280 address, 0x76(118)
# Read data back from 0xF7(247), 8 bytes
# Pressure MSB, Pressure LSB, Pressure xLSB, Temperature MSB, Temperature LSB
# Temperature xLSB, Humidity MSB, Humidity LSB
data = bus.read_i2c_block_data(0x76, 0xF7, 8)

# Convert pressure and temperature data to 19-bits
adc_p = ((data[0] * 65536) + (data[1] * 256) + (data[2] & 0xF0)) / 16
adc_t = ((data[3] * 65536) + (data[4] * 256) + (data[5] & 0xF0)) / 16

# Convert the humidity data
adc_h = data[6] * 256 + data[7]

# Temperature offset calculations
var1 = ((adc_t) / 16384.0 - (dig_T1) / 1024.0) * (dig_T2)
var2 = (((adc_t) / 131072.0 - (dig_T1) / 8192.0) * ((adc_t)/131072.0 - (dig_T1)/8192.0)) * (dig_T3)
t_fine = (var1 + var2)
cTemp = (var1 + var2) / 5120.0
fTemp = cTemp * 1.8 + 32

# Pressure offset calculations
var1 = (t_fine / 2.0) - 64000.0
var2 = var1 * var1 * (dig_P6) / 32768.0
var2 = var2 + var1 * (dig_P5) * 2.0
var2 = (var2 / 4.0) + ((dig_P4) * 65536.0)
var1 = ((dig_P3) * var1 * var1 / 524288.0 + ( dig_P2) * var1) / 524288.0
var1 = (1.0 + var1 / 32768.0) * (dig_P1)
p = 1048576.0 - adc_p
p = (p - (var2 / 4096.0)) * 6250.0 / var1
var1 = (dig_P9) * p * p / 2147483648.0
var2 = p * (dig_P8) / 32768.0
pressure = (p + (var1 + var2 + (dig_P7)) / 16.0) / 100

# Humidity offset calculations
var_H = ((t_fine) - 76800.0)
var_H = (adc_h - (dig_H4 * 64.0 + dig_H5 / 16384.0 * var_H)) * (dig_H2 / 65536.0 * (1.0 + dig_H6 / 67108864.0 * var_H * (1.0 + dig_H3 / 67108864.0 * var_H)))
humidity = var_H * (1.0 -  dig_H1 * var_H / 524288.0)
if humidity > 100.0 :
    humidity = 100.0
elif humidity < 0.0 :
    humidity = 0.0

# Output data to screen
print "Temperature in Celsius : %.2f C" %cTemp
print "Temperature in Fahrenheit : %.2f F" %fTemp
print "Pressure : %.2f hPa " %pressure
print "Relative Humidity : %.2f %%" %humidity

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import smbus

import time

# Get I2C bus

bus = smbus.SMBus(1)

# BME280 address, 0x76(118)

# Read data back from 0x88(136), 24 bytes

b1 = bus.read_i2c_block_data(0x76, 0x88, 24)

# Convert the data

# Temp coefficients

dig_T1 = b1[1] * 256 + b1[0]

dig_T2 = b1[3] * 256 + b1[2]

if dig_T2 > 32767 :

dig_T2 -= 65536

dig_T3 = b1[5] * 256 + b1[4]

if dig_T3 > 32767 :

dig_T3 -= 65536

# Pressure coefficients

dig_P1 = b1[7] * 256 + b1[6]

dig_P2 = b1[9] * 256 + b1[8]

if dig_P2 > 32767 :

dig_P2 -= 65536

dig_P3 = b1[11] * 256 + b1[10]

if dig_P3 > 32767 :

dig_P3 -= 65536

dig_P4 = b1[13] * 256 + b1[12]

if dig_P4 > 32767 :

dig_P4 -= 65536

dig_P5 = b1[15] * 256 + b1[14]

if dig_P5 > 32767 :

dig_P5 -= 65536

dig_P6 = b1[17] * 256 + b1[16]

if dig_P6 > 32767 :

dig_P6 -= 65536

dig_P7 = b1[19] * 256 + b1[18]

if dig_P7 > 32767 :

dig_P7 -= 65536

dig_P8 = b1[21] * 256 + b1[20]

if dig_P8 > 32767 :

dig_P8 -= 65536

dig_P9 = b1[23] * 256 + b1[22]

if dig_P9 > 32767 :

dig_P9 -= 65536

# BME280 address, 0x76(118)

# Read data back from 0xA1(161), 1 byte

dig_H1 = bus.read_byte_data(0x76, 0xA1)

# BME280 address, 0x76(118)

# Read data back from 0xE1(225), 7 bytes

b1 = bus.read_i2c_block_data(0x76, 0xE1, 7)

# Convert the data

# Humidity coefficients

dig_H2 = b1[1] * 256 + b1[0]

if dig_H2 > 32767 :

dig_H2 -= 65536

dig_H3 = (b1[2] & 0xFF)

dig_H4 = (b1[3] * 16) + (b1[4] & 0xF)

if dig_H4 > 32767 :

dig_H4 -= 65536

dig_H5 = (b1[4] / 16) + (b1[5] * 16)

if dig_H5 > 32767 :

dig_H5 -= 65536

dig_H6 = b1[6]

if dig_H6 > 127 :

dig_H6 -= 256

# BME280 address, 0x76(118)

# Select control humidity register, 0xF2(242)

# 0x01(01) Humidity Oversampling = 1

bus.write_byte_data(0x76, 0xF2, 0x01)

# BME280 address, 0x76(118)

# Select Control measurement register, 0xF4(244)

# 0x27(39) Pressure and Temperature Oversampling rate = 1

# Normal mode

bus.write_byte_data(0x76, 0xF4, 0x27)

# BME280 address, 0x76(118)

# Select Configuration register, 0xF5(245)

# 0xA0(00) Stand_by time = 1000 ms

bus.write_byte_data(0x76, 0xF5, 0xA0)

time.sleep(0.5)

# BME280 address, 0x76(118)

# Read data back from 0xF7(247), 8 bytes

# Pressure MSB, Pressure LSB, Pressure xLSB, Temperature MSB, Temperature LSB

# Temperature xLSB, Humidity MSB, Humidity LSB

data = bus.read_i2c_block_data(0x76, 0xF7, 8)

# Convert pressure and temperature data to 19-bits

adc_p = ((data[0] * 65536) + (data[1] * 256) + (data[2] & 0xF0)) / 16

adc_t = ((data[3] * 65536) + (data[4] * 256) + (data[5] & 0xF0)) / 16

# Convert the humidity data

adc_h = data[6] * 256 + data[7]

# Temperature offset calculations

var1 = ((adc_t) / 16384.0 - (dig_T1) / 1024.0) * (dig_T2)

var2 = (((adc_t) / 131072.0 - (dig_T1) / 8192.0) * ((adc_t)/131072.0 - (dig_T1)/8192.0)) * (dig_T3)

t_fine = (var1 + var2)

cTemp = (var1 + var2) / 5120.0

fTemp = cTemp * 1.8 + 32

# Pressure offset calculations

var1 = (t_fine / 2.0) - 64000.0

var2 = var1 * var1 * (dig_P6) / 32768.0

var2 = var2 + var1 * (dig_P5) * 2.0

var2 = (var2 / 4.0) + ((dig_P4) * 65536.0)

var1 = ((dig_P3) * var1 * var1 / 524288.0 + ( dig_P2) * var1) / 524288.0

var1 = (1.0 + var1 / 32768.0) * (dig_P1)

p = 1048576.0 - adc_p

p = (p - (var2 / 4096.0)) * 6250.0 / var1

var1 = (dig_P9) * p * p / 2147483648.0

var2 = p * (dig_P8) / 32768.0

pressure = (p + (var1 + var2 + (dig_P7)) / 16.0) / 100

# Humidity offset calculations

var_H = ((t_fine) - 76800.0)

var_H = (adc_h - (dig_H4 * 64.0 + dig_H5 / 16384.0 * var_H)) * (dig_H2 / 65536.0 * (1.0 + dig_H6 / 67108864.0 * var_H * (1.0 + dig_H3 / 67108864.0 * var_H)))

humidity = var_H * (1.0 - dig_H1 * var_H / 524288.0)

if humidity > 100.0 :

humidity = 100.0

elif humidity < 0.0 :

humidity = 0.0

# Output data to screen

print "Temperature in Celsius : %.2f C" %cTemp

print "Temperature in Fahrenheit : %.2f F" %fTemp

print "Pressure : %.2f hPa " %pressure

print "Relative Humidity : %.2f %%" %humidity

Start het script met: sudo python bme280.py, resultaat:

Temperature in Celsius : 25.50 C
Temperature in Fahrenheit : 77.89 F
Pressure : 1019.44 hPa
Relative Humidity : 49.21 %

Temperature in Celsius : 25.50 C

Temperature in Fahrenheit : 77.89 F

Pressure : 1019.44 hPa

Relative Humidity : 49.21 %

Script #2

#!/usr/bin/python
#--------------------------------------
#    ___  ___  _ ____
#   / _ \/ _ \(_) __/__  __ __
#  / , _/ ___/ /\ \/ _ \/ // /
# /_/|_/_/  /_/___/ .__/\_, /
#                /_/   /___/
#
#           bme280.py
#  Read data from a digital pressure sensor.
#
#  Official datasheet available from :
#  https://www.bosch-sensortec.com/bst/products/all_products/bme280
#
# Author : Matt Hawkins
# Date   : 25/07/2016
#
# http://www.raspberrypi-spy.co.uk/
#
#--------------------------------------
import smbus
import time
from ctypes import c_short
from ctypes import c_byte
from ctypes import c_ubyte

DEVICE = 0x76 # Default device I2C address


bus = smbus.SMBus(1) # Rev 2 Pi, Pi 2 & Pi 3 uses bus 1
                     # Rev 1 Pi uses bus 0

def getShort(data, index):
  # return two bytes from data as a signed 16-bit value
  return c_short((data[index+1] << 8) + data[index]).value

def getUShort(data, index):
  # return two bytes from data as an unsigned 16-bit value
  return (data[index+1] << 8) + data[index]

def getChar(data,index):
  # return one byte from data as a signed char
  result = data[index]
  if result > 127:
    result -= 256
  return result

def getUChar(data,index):
  # return one byte from data as an unsigned char
  result =  data[index] & 0xFF
  return result

def readBME280ID(addr=DEVICE):
  # Chip ID Register Address
  REG_ID     = 0xD0
  (chip_id, chip_version) = bus.read_i2c_block_data(addr, REG_ID, 2)
  return (chip_id, chip_version)

def readBME280All(addr=DEVICE):
  # Register Addresses
  REG_DATA = 0xF7
  REG_CONTROL = 0xF4
  REG_CONFIG  = 0xF5

  REG_CONTROL_HUM = 0xF2
  REG_HUM_MSB = 0xFD
  REG_HUM_LSB = 0xFE

  # Oversample setting - page 27
  OVERSAMPLE_TEMP = 2
  OVERSAMPLE_PRES = 2
  MODE = 1

  # Oversample setting for humidity register - page 26
  OVERSAMPLE_HUM = 2
  bus.write_byte_data(addr, REG_CONTROL_HUM, OVERSAMPLE_HUM)

  control = OVERSAMPLE_TEMP<<5 | OVERSAMPLE_PRES<<2 | MODE
  bus.write_byte_data(addr, REG_CONTROL, control)

  # Read blocks of calibration data from EEPROM
  # See Page 22 data sheet
  cal1 = bus.read_i2c_block_data(addr, 0x88, 24)
  cal2 = bus.read_i2c_block_data(addr, 0xA1, 1)
  cal3 = bus.read_i2c_block_data(addr, 0xE1, 7)

  # Convert byte data to word values
  dig_T1 = getUShort(cal1, 0)
  dig_T2 = getShort(cal1, 2)
  dig_T3 = getShort(cal1, 4)

  dig_P1 = getUShort(cal1, 6)
  dig_P2 = getShort(cal1, 8)
  dig_P3 = getShort(cal1, 10)
  dig_P4 = getShort(cal1, 12)
  dig_P5 = getShort(cal1, 14)
  dig_P6 = getShort(cal1, 16)
  dig_P7 = getShort(cal1, 18)
  dig_P8 = getShort(cal1, 20)
  dig_P9 = getShort(cal1, 22)

  dig_H1 = getUChar(cal2, 0)
  dig_H2 = getShort(cal3, 0)
  dig_H3 = getUChar(cal3, 2)

  dig_H4 = getChar(cal3, 3)
  dig_H4 = (dig_H4 << 24) >> 20
  dig_H4 = dig_H4 | (getChar(cal3, 4) & 0x0F)

  dig_H5 = getChar(cal3, 5)
  dig_H5 = (dig_H5 << 24) >> 20
  dig_H5 = dig_H5 | (getUChar(cal3, 4) >> 4 & 0x0F)

  dig_H6 = getChar(cal3, 6)

  # Wait in ms (Datasheet Appendix B: Measurement time and current calculation)
  wait_time = 1.25 + (2.3 * OVERSAMPLE_TEMP) + ((2.3 * OVERSAMPLE_PRES) + 0.575) + ((2.3 * OVERSAMPLE_HUM)+0.575)
  time.sleep(wait_time/1000)  # Wait the required time  

  # Read temperature/pressure/humidity
  data = bus.read_i2c_block_data(addr, REG_DATA, 8)
  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]

  #Refine temperature
  var1 = ((((temp_raw>>3)-(dig_T1<<1)))*(dig_T2)) >> 11
  var2 = (((((temp_raw>>4) - (dig_T1)) * ((temp_raw>>4) - (dig_T1))) >> 12) * (dig_T3)) >> 14
  t_fine = var1+var2
  temperature = float(((t_fine * 5) + 128) >> 8);

  # Refine pressure and adjust for temperature
  var1 = t_fine / 2.0 - 64000.0
  var2 = var1 * var1 * dig_P6 / 32768.0
  var2 = var2 + var1 * dig_P5 * 2.0
  var2 = var2 / 4.0 + dig_P4 * 65536.0
  var1 = (dig_P3 * var1 * var1 / 524288.0 + dig_P2 * var1) / 524288.0
  var1 = (1.0 + var1 / 32768.0) * dig_P1
  if var1 == 0:
    pressure=0
  else:
    pressure = 1048576.0 - pres_raw
    pressure = ((pressure - var2 / 4096.0) * 6250.0) / var1
    var1 = dig_P9 * pressure * pressure / 2147483648.0
    var2 = pressure * dig_P8 / 32768.0
    pressure = pressure + (var1 + var2 + dig_P7) / 16.0

  # Refine humidity
  humidity = t_fine - 76800.0
  humidity = (hum_raw - (dig_H4 * 64.0 + dig_H5 / 16384.0 * humidity)) * (dig_H2 / 65536.0 * (1.0 + dig_H6 / 67108864.0 * humidity * (1.0 + dig_H3 / 67108864.0 * humidity)))
  humidity = humidity * (1.0 - dig_H1 * humidity / 524288.0)
  if humidity > 100:
    humidity = 100
  elif humidity < 0:
    humidity = 0

  return temperature/100.0,pressure/100.0,humidity

def main():

  (chip_id, chip_version) = readBME280ID()
  print "Chip ID     :", chip_id
  print "Version     :", chip_version

  temperature,pressure,humidity = readBME280All()

  print "Temperature : ", temperature, "C"
  print "Pressure : ", pressure, "hPa"
  print "Humidity : ", humidity, "%"

if __name__=="__main__":
   main()

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#!/usr/bin/python

#--------------------------------------

# ___ ___ _ ____

# / _ \/ _ \(_) __/__ __ __

# / , _/ ___/ /\ \/ _ \/ // /

# /_/|_/_/ /_/___/ .__/\_, /

# /_/ /___/

# bme280.py

# Read data from a digital pressure sensor.

# Official datasheet available from :

# https://www.bosch-sensortec.com/bst/products/all_products/bme280

# Author : Matt Hawkins

# Date : 25/07/2016

# http://www.raspberrypi-spy.co.uk/

#--------------------------------------

import smbus

import time

from ctypes import c_short

from ctypes import c_byte

from ctypes import c_ubyte

DEVICE = 0x76 # Default device I2C address

bus = smbus.SMBus(1) # Rev 2 Pi, Pi 2 & Pi 3 uses bus 1

# Rev 1 Pi uses bus 0

def getShort(data, index):

# return two bytes from data as a signed 16-bit value

return c_short((data[index+1] << 8) + data[index]).value

def getUShort(data, index):

# return two bytes from data as an unsigned 16-bit value

return (data[index+1] << 8) + data[index]

def getChar(data,index):

# return one byte from data as a signed char

result = data[index]

if result > 127:

result -= 256

return result

def getUChar(data,index):

# return one byte from data as an unsigned char

result = data[index] & 0xFF

return result

def readBME280ID(addr=DEVICE):

# Chip ID Register Address

REG_ID = 0xD0

(chip_id, chip_version) = bus.read_i2c_block_data(addr, REG_ID, 2)

return (chip_id, chip_version)

def readBME280All(addr=DEVICE):

# Register Addresses

REG_DATA = 0xF7

REG_CONTROL = 0xF4

REG_CONFIG = 0xF5

REG_CONTROL_HUM = 0xF2

REG_HUM_MSB = 0xFD

REG_HUM_LSB = 0xFE

# Oversample setting - page 27

OVERSAMPLE_TEMP = 2

OVERSAMPLE_PRES = 2

MODE = 1

# Oversample setting for humidity register - page 26

OVERSAMPLE_HUM = 2

bus.write_byte_data(addr, REG_CONTROL_HUM, OVERSAMPLE_HUM)

control = OVERSAMPLE_TEMP<<5 | OVERSAMPLE_PRES<<2 | MODE

bus.write_byte_data(addr, REG_CONTROL, control)

# Read blocks of calibration data from EEPROM

# See Page 22 data sheet

cal1 = bus.read_i2c_block_data(addr, 0x88, 24)

cal2 = bus.read_i2c_block_data(addr, 0xA1, 1)

cal3 = bus.read_i2c_block_data(addr, 0xE1, 7)

# Convert byte data to word values

dig_T1 = getUShort(cal1, 0)

dig_T2 = getShort(cal1, 2)

dig_T3 = getShort(cal1, 4)

dig_P1 = getUShort(cal1, 6)

dig_P2 = getShort(cal1, 8)

dig_P3 = getShort(cal1, 10)

dig_P4 = getShort(cal1, 12)

dig_P5 = getShort(cal1, 14)

dig_P6 = getShort(cal1, 16)

dig_P7 = getShort(cal1, 18)

dig_P8 = getShort(cal1, 20)

dig_P9 = getShort(cal1, 22)

dig_H1 = getUChar(cal2, 0)

dig_H2 = getShort(cal3, 0)

dig_H3 = getUChar(cal3, 2)

dig_H4 = getChar(cal3, 3)

dig_H4 = (dig_H4 << 24) >> 20

dig_H4 = dig_H4 | (getChar(cal3, 4) & 0x0F)

dig_H5 = getChar(cal3, 5)

dig_H5 = (dig_H5 << 24) >> 20

dig_H5 = dig_H5 | (getUChar(cal3, 4) >> 4 & 0x0F)

dig_H6 = getChar(cal3, 6)

# Wait in ms (Datasheet Appendix B: Measurement time and current calculation)

wait_time = 1.25 + (2.3 * OVERSAMPLE_TEMP) + ((2.3 * OVERSAMPLE_PRES) + 0.575) + ((2.3 * OVERSAMPLE_HUM)+0.575)

time.sleep(wait_time/1000) # Wait the required time

# Read temperature/pressure/humidity

data = bus.read_i2c_block_data(addr, REG_DATA, 8)

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]

#Refine temperature

var1 = ((((temp_raw>>3)-(dig_T1<<1)))*(dig_T2)) >> 11

var2 = (((((temp_raw>>4) - (dig_T1)) * ((temp_raw>>4) - (dig_T1))) >> 12) * (dig_T3)) >> 14

t_fine = var1+var2

temperature = float(((t_fine * 5) + 128) >> 8);

# Refine pressure and adjust for temperature

var1 = t_fine / 2.0 - 64000.0

var2 = var1 * var1 * dig_P6 / 32768.0

var2 = var2 + var1 * dig_P5 * 2.0

var2 = var2 / 4.0 + dig_P4 * 65536.0

var1 = (dig_P3 * var1 * var1 / 524288.0 + dig_P2 * var1) / 524288.0

var1 = (1.0 + var1 / 32768.0) * dig_P1

if var1 == 0:

pressure=0

else:

pressure = 1048576.0 - pres_raw

pressure = ((pressure - var2 / 4096.0) * 6250.0) / var1

var1 = dig_P9 * pressure * pressure / 2147483648.0

var2 = pressure * dig_P8 / 32768.0

pressure = pressure + (var1 + var2 + dig_P7) / 16.0

# Refine humidity

humidity = t_fine - 76800.0

humidity = (hum_raw - (dig_H4 * 64.0 + dig_H5 / 16384.0 * humidity)) * (dig_H2 / 65536.0 * (1.0 + dig_H6 / 67108864.0 * humidity * (1.0 + dig_H3 / 67108864.0 * humidity)))

humidity = humidity * (1.0 - dig_H1 * humidity / 524288.0)

if humidity > 100:

humidity = 100

elif humidity < 0:

humidity = 0

return temperature/100.0,pressure/100.0,humidity

def main():

(chip_id, chip_version) = readBME280ID()

print "Chip ID :", chip_id

print "Version :", chip_version

temperature,pressure,humidity = readBME280All()

print "Temperature : ", temperature, "C"

print "Pressure : ", pressure, "hPa"

print "Humidity : ", humidity, "%"

if __name__=="__main__":

main()

Output:

Importeren vanuit een ander script is mogelijk, gebruik onderstaand voorbeeld:

import bme280
 
(chip_id, chip_version) = bme280.readBME280ID()
print "Chip ID :", chip_id
print "Version :", chip_version
 
temperature,pressure,humidity = bme280.readBME280All()
 
print "Temperature : ", temperature, "C"
print "Pressure : ", pressure, "hPa"
print "Humidity : ", humidity, "%"

import bme280

(chip_id, chip_version) = bme280.readBME280ID()

print "Chip ID :", chip_id

print "Version :", chip_version

temperature,pressure,humidity = bme280.readBME280All()

print "Temperature : ", temperature, "C"

print "Pressure : ", pressure, "hPa"

print "Humidity : ", humidity, "%"

Bronnen:
ControlEverythongCommunity @ Github.com
raspberrypi-spy.co.uk

Schema

Teardown

GEEN GEGEVENS

Datasheet

BME280 datasheet bosch

Fritzing

Download @ omnigatherum

BME280_Breakout_Board.fzpz 23,55 kb

Downloads

GEEN GEGEVENS

Zoeken

Sensor – BME280 – Temperatuur, Luchtvochtigheid en Barometrische druk sensor

Hardware

Pinout

Arduino

Script met BME280 bibliotheek

Script met alleen wire bibliotheek

Script met BME280 bibliotheek op SPI

Arduino Library

BME280 Library

Summary

Installation

Usage

Enumerations

TempUnit Enum

PresUnit Enum

OSR Enum

Mode Enum

StandbyTime Enum

Filter Enum

ChipModel Enum

Settings

BME280::Settings Struct

BME280I2C::Settings Struct

BME280Spi::Settings Struct

BME280Spi::Settings Struct

Methods

BME280I2C(const BME280I2C::Settings& settings)

BME280Spi(const BME280Spi::Settings& settings)

BME280SpiSw(const BME280SpiSw::Settings& settings)

bool begin()

void setSettings(const Settings& settings)

const Settings& getSettings() const

float temp(TempUnit unit)

float pres(PresUnit unit)

float hum()

void read(float& pressure, float& temp, float& humidity, TempUnit tempUnit, PresUnit presUnit)

ChipModel chipModel()

Environment Calculations

float Altitude(float pressure, AltitudeUnit = AltitudeUnit_Meters, float seaLevelPressure = 1013.25, outsideTemp = 15.0, TempUnit = TempUnit_Celsius)

float EquivalentSeaLevelPressure(float altitude, float temp, float pres, AltitudeUnit altUnit, TempUnit tempUnit )

float DewPoint(float temp, float hum, TempUnit = TempUnit_Celsius)

float AbsoluteHumidity(float temperature, float humidity, TempUnit = TempUnit_Celsius)

int HeatIndex(float temperature, float humidity, TempUnit tempUnit = TempUnit_Celsius)

History

Raspberry Pi

Controleren van de aansluiting

Script #2

Schema

Teardown

Datasheet

Fritzing

Downloads