weatherstation/firmware/libraries/Adafruit_BMP280_Library/Adafruit_BMP280.cpp
2022-11-11 11:11:25 +01:00

493 lines
15 KiB
C++

/*!
* @file Adafruit_BMP280.cpp
*
* This is a library for the BMP280 orientation sensor
*
* Designed specifically to work with the Adafruit BMP280 Sensor.
*
* Pick one up today in the adafruit shop!
* ------> https://www.adafruit.com/product/2651
*
* These sensors use I2C to communicate, 2 pins are required to interface.
*
* Adafruit invests time and resources providing this open source code,
* please support Adafruit andopen-source hardware by purchasing products
* from Adafruit!
*
* K.Townsend (Adafruit Industries)
*
* BSD license, all text above must be included in any redistribution
*/
#include <Adafruit_BMP280.h>
/*!
* @brief BMP280 constructor using i2c
* @param *theWire
* optional wire
*/
Adafruit_BMP280::Adafruit_BMP280(TwoWire *theWire) {
_wire = theWire;
temp_sensor = new Adafruit_BMP280_Temp(this);
pressure_sensor = new Adafruit_BMP280_Pressure(this);
}
/*!
* @brief BMP280 constructor using hardware SPI
* @param cspin
* cs pin number
* @param theSPI
* optional SPI object
*/
Adafruit_BMP280::Adafruit_BMP280(int8_t cspin, SPIClass *theSPI) {
spi_dev = new Adafruit_SPIDevice(cspin, 1000000, SPI_BITORDER_MSBFIRST,
SPI_MODE0, theSPI);
temp_sensor = new Adafruit_BMP280_Temp(this);
pressure_sensor = new Adafruit_BMP280_Pressure(this);
}
/*!
* @brief BMP280 constructor using bitbang SPI
* @param cspin
* The pin to use for CS/SSEL.
* @param mosipin
* The pin to use for MOSI.
* @param misopin
* The pin to use for MISO.
* @param sckpin
* The pin to use for SCK.
*/
Adafruit_BMP280::Adafruit_BMP280(int8_t cspin, int8_t mosipin, int8_t misopin,
int8_t sckpin) {
spi_dev = new Adafruit_SPIDevice(cspin, sckpin, misopin, mosipin);
temp_sensor = new Adafruit_BMP280_Temp(this);
pressure_sensor = new Adafruit_BMP280_Pressure(this);
}
Adafruit_BMP280::~Adafruit_BMP280(void) {
if (spi_dev)
delete spi_dev;
if (i2c_dev)
delete i2c_dev;
if (temp_sensor)
delete temp_sensor;
if (pressure_sensor)
delete pressure_sensor;
}
/*!
* Initialises the sensor.
* @param addr
* The I2C address to use (default = 0x77)
* @param chipid
* The expected chip ID (used to validate connection).
* @return True if the init was successful, otherwise false.
*/
bool Adafruit_BMP280::begin(uint8_t addr, uint8_t chipid) {
if (spi_dev == NULL) {
// I2C mode
if (i2c_dev)
delete i2c_dev;
i2c_dev = new Adafruit_I2CDevice(addr, _wire);
if (!i2c_dev->begin())
return false;
} else {
// SPI mode
if (!spi_dev->begin())
return false;
}
// check if sensor, i.e. the chip ID is correct
_sensorID = read8(BMP280_REGISTER_CHIPID);
if (_sensorID != chipid)
return false;
readCoefficients();
// write8(BMP280_REGISTER_CONTROL, 0x3F); /* needed? */
setSampling();
delay(100);
return true;
}
/*!
* Sets the sampling config for the device.
* @param mode
* The operating mode of the sensor.
* @param tempSampling
* The sampling scheme for temp readings.
* @param pressSampling
* The sampling scheme for pressure readings.
* @param filter
* The filtering mode to apply (if any).
* @param duration
* The sampling duration.
*/
void Adafruit_BMP280::setSampling(sensor_mode mode,
sensor_sampling tempSampling,
sensor_sampling pressSampling,
sensor_filter filter,
standby_duration duration) {
if (!_sensorID)
return; // begin() not called yet
_measReg.mode = mode;
_measReg.osrs_t = tempSampling;
_measReg.osrs_p = pressSampling;
_configReg.filter = filter;
_configReg.t_sb = duration;
write8(BMP280_REGISTER_CONFIG, _configReg.get());
write8(BMP280_REGISTER_CONTROL, _measReg.get());
}
/**************************************************************************/
/*!
@brief Writes an 8 bit value over I2C/SPI
*/
/**************************************************************************/
void Adafruit_BMP280::write8(byte reg, byte value) {
byte buffer[2];
buffer[1] = value;
if (i2c_dev) {
buffer[0] = reg;
i2c_dev->write(buffer, 2);
} else {
buffer[0] = reg & ~0x80;
spi_dev->write(buffer, 2);
}
}
/*!
* @brief Reads an 8 bit value over I2C/SPI
* @param reg
* selected register
* @return value from selected register
*/
uint8_t Adafruit_BMP280::read8(byte reg) {
uint8_t buffer[1];
if (i2c_dev) {
buffer[0] = uint8_t(reg);
i2c_dev->write_then_read(buffer, 1, buffer, 1);
} else {
buffer[0] = uint8_t(reg | 0x80);
spi_dev->write_then_read(buffer, 1, buffer, 1);
}
return buffer[0];
}
/*!
* @brief Reads a 16 bit value over I2C/SPI
*/
uint16_t Adafruit_BMP280::read16(byte reg) {
uint8_t buffer[2];
if (i2c_dev) {
buffer[0] = uint8_t(reg);
i2c_dev->write_then_read(buffer, 1, buffer, 2);
} else {
buffer[0] = uint8_t(reg | 0x80);
spi_dev->write_then_read(buffer, 1, buffer, 2);
}
return uint16_t(buffer[0]) << 8 | uint16_t(buffer[1]);
}
uint16_t Adafruit_BMP280::read16_LE(byte reg) {
uint16_t temp = read16(reg);
return (temp >> 8) | (temp << 8);
}
/*!
* @brief Reads a signed 16 bit value over I2C/SPI
*/
int16_t Adafruit_BMP280::readS16(byte reg) { return (int16_t)read16(reg); }
int16_t Adafruit_BMP280::readS16_LE(byte reg) {
return (int16_t)read16_LE(reg);
}
/*!
* @brief Reads a 24 bit value over I2C/SPI
*/
uint32_t Adafruit_BMP280::read24(byte reg) {
uint8_t buffer[3];
if (i2c_dev) {
buffer[0] = uint8_t(reg);
i2c_dev->write_then_read(buffer, 1, buffer, 3);
} else {
buffer[0] = uint8_t(reg | 0x80);
spi_dev->write_then_read(buffer, 1, buffer, 3);
}
return uint32_t(buffer[0]) << 16 | uint32_t(buffer[1]) << 8 |
uint32_t(buffer[2]);
}
/*!
* @brief Reads the factory-set coefficients
*/
void Adafruit_BMP280::readCoefficients() {
_bmp280_calib.dig_T1 = read16_LE(BMP280_REGISTER_DIG_T1);
_bmp280_calib.dig_T2 = readS16_LE(BMP280_REGISTER_DIG_T2);
_bmp280_calib.dig_T3 = readS16_LE(BMP280_REGISTER_DIG_T3);
_bmp280_calib.dig_P1 = read16_LE(BMP280_REGISTER_DIG_P1);
_bmp280_calib.dig_P2 = readS16_LE(BMP280_REGISTER_DIG_P2);
_bmp280_calib.dig_P3 = readS16_LE(BMP280_REGISTER_DIG_P3);
_bmp280_calib.dig_P4 = readS16_LE(BMP280_REGISTER_DIG_P4);
_bmp280_calib.dig_P5 = readS16_LE(BMP280_REGISTER_DIG_P5);
_bmp280_calib.dig_P6 = readS16_LE(BMP280_REGISTER_DIG_P6);
_bmp280_calib.dig_P7 = readS16_LE(BMP280_REGISTER_DIG_P7);
_bmp280_calib.dig_P8 = readS16_LE(BMP280_REGISTER_DIG_P8);
_bmp280_calib.dig_P9 = readS16_LE(BMP280_REGISTER_DIG_P9);
}
/*!
* Reads the temperature from the device.
* @return The temperature in degrees celsius.
*/
float Adafruit_BMP280::readTemperature() {
int32_t var1, var2;
if (!_sensorID)
return NAN; // begin() not called yet
int32_t adc_T = read24(BMP280_REGISTER_TEMPDATA);
adc_T >>= 4;
var1 = ((((adc_T >> 3) - ((int32_t)_bmp280_calib.dig_T1 << 1))) *
((int32_t)_bmp280_calib.dig_T2)) >>
11;
var2 = (((((adc_T >> 4) - ((int32_t)_bmp280_calib.dig_T1)) *
((adc_T >> 4) - ((int32_t)_bmp280_calib.dig_T1))) >>
12) *
((int32_t)_bmp280_calib.dig_T3)) >>
14;
t_fine = var1 + var2;
float T = (t_fine * 5 + 128) >> 8;
return T / 100;
}
/*!
* Reads the barometric pressure from the device.
* @return Barometric pressure in Pa.
*/
float Adafruit_BMP280::readPressure() {
int64_t var1, var2, p;
if (!_sensorID)
return NAN; // begin() not called yet
// Must be done first to get the t_fine variable set up
readTemperature();
int32_t adc_P = read24(BMP280_REGISTER_PRESSUREDATA);
adc_P >>= 4;
var1 = ((int64_t)t_fine) - 128000;
var2 = var1 * var1 * (int64_t)_bmp280_calib.dig_P6;
var2 = var2 + ((var1 * (int64_t)_bmp280_calib.dig_P5) << 17);
var2 = var2 + (((int64_t)_bmp280_calib.dig_P4) << 35);
var1 = ((var1 * var1 * (int64_t)_bmp280_calib.dig_P3) >> 8) +
((var1 * (int64_t)_bmp280_calib.dig_P2) << 12);
var1 =
(((((int64_t)1) << 47) + var1)) * ((int64_t)_bmp280_calib.dig_P1) >> 33;
if (var1 == 0) {
return 0; // avoid exception caused by division by zero
}
p = 1048576 - adc_P;
p = (((p << 31) - var2) * 3125) / var1;
var1 = (((int64_t)_bmp280_calib.dig_P9) * (p >> 13) * (p >> 13)) >> 25;
var2 = (((int64_t)_bmp280_calib.dig_P8) * p) >> 19;
p = ((p + var1 + var2) >> 8) + (((int64_t)_bmp280_calib.dig_P7) << 4);
return (float)p / 256;
}
/*!
* @brief Calculates the approximate altitude using barometric pressure and the
* supplied sea level hPa as a reference.
* @param seaLevelhPa
* The current hPa at sea level.
* @return The approximate altitude above sea level in meters.
*/
float Adafruit_BMP280::readAltitude(float seaLevelhPa) {
float altitude;
float pressure = readPressure(); // in Si units for Pascal
pressure /= 100;
altitude = 44330 * (1.0 - pow(pressure / seaLevelhPa, 0.1903));
return altitude;
}
/*!
* Calculates the pressure at sea level (QNH) from the specified altitude,
* and atmospheric pressure (QFE).
* @param altitude Altitude in m
* @param atmospheric Atmospheric pressure in hPa
* @return The approximate pressure in hPa
*/
float Adafruit_BMP280::seaLevelForAltitude(float altitude, float atmospheric) {
// Equation taken from BMP180 datasheet (page 17):
// http://www.adafruit.com/datasheets/BST-BMP180-DS000-09.pdf
// Note that using the equation from wikipedia can give bad results
// at high altitude. See this thread for more information:
// http://forums.adafruit.com/viewtopic.php?f=22&t=58064
return atmospheric / pow(1.0 - (altitude / 44330.0), 5.255);
}
/*!
@brief calculates the boiling point of water by a given pressure
@param pressure pressure in hPa
@return temperature in °C
*/
float Adafruit_BMP280::waterBoilingPoint(float pressure) {
// Magnusformular for calculation of the boiling point of water at a given
// pressure
return (234.175 * log(pressure / 6.1078)) /
(17.08085 - log(pressure / 6.1078));
}
/*!
@brief Take a new measurement (only possible in forced mode)
@return true if successful, otherwise false
*/
bool Adafruit_BMP280::takeForcedMeasurement() {
// If we are in forced mode, the BME sensor goes back to sleep after each
// measurement and we need to set it to forced mode once at this point, so
// it will take the next measurement and then return to sleep again.
// In normal mode simply does new measurements periodically.
if (_measReg.mode == MODE_FORCED) {
// set to forced mode, i.e. "take next measurement"
write8(BMP280_REGISTER_CONTROL, _measReg.get());
// wait until measurement has been completed, otherwise we would read
// the values from the last measurement
while (read8(BMP280_REGISTER_STATUS) & 0x08)
delay(1);
return true;
}
return false;
}
/*!
* @brief Resets the chip via soft reset
*/
void Adafruit_BMP280::reset(void) {
write8(BMP280_REGISTER_SOFTRESET, MODE_SOFT_RESET_CODE);
}
/*!
* Returns Sensor ID for diagnostics
* @returns 0x61 for BME680, 0x60 for BME280, 0x56, 0x57, 0x58 for BMP280
*/
uint8_t Adafruit_BMP280::sensorID(void) { return _sensorID; };
/*!
@brief Gets the most recent sensor event from the hardware status register.
@return Sensor status as a byte.
*/
uint8_t Adafruit_BMP280::getStatus(void) {
return read8(BMP280_REGISTER_STATUS);
}
/*!
@brief Gets an Adafruit Unified Sensor object for the temp sensor component
@return Adafruit_Sensor pointer to temperature sensor
*/
Adafruit_Sensor *Adafruit_BMP280::getTemperatureSensor(void) {
return temp_sensor;
}
/*!
@brief Gets an Adafruit Unified Sensor object for the pressure sensor
component
@return Adafruit_Sensor pointer to pressure sensor
*/
Adafruit_Sensor *Adafruit_BMP280::getPressureSensor(void) {
return pressure_sensor;
}
/**************************************************************************/
/*!
@brief Gets the sensor_t data for the BMP280's temperature sensor
*/
/**************************************************************************/
void Adafruit_BMP280_Temp::getSensor(sensor_t *sensor) {
/* Clear the sensor_t object */
memset(sensor, 0, sizeof(sensor_t));
/* Insert the sensor name in the fixed length char array */
strncpy(sensor->name, "BMP280", sizeof(sensor->name) - 1);
sensor->name[sizeof(sensor->name) - 1] = 0;
sensor->version = 1;
sensor->sensor_id = _sensorID;
sensor->type = SENSOR_TYPE_AMBIENT_TEMPERATURE;
sensor->min_delay = 0;
sensor->min_value = -40.0; /* Temperature range -40 ~ +85 C */
sensor->max_value = +85.0;
sensor->resolution = 0.01; /* 0.01 C */
}
/**************************************************************************/
/*!
@brief Gets the temperature as a standard sensor event
@param event Sensor event object that will be populated
@returns True
*/
/**************************************************************************/
bool Adafruit_BMP280_Temp::getEvent(sensors_event_t *event) {
/* Clear the event */
memset(event, 0, sizeof(sensors_event_t));
event->version = sizeof(sensors_event_t);
event->sensor_id = _sensorID;
event->type = SENSOR_TYPE_AMBIENT_TEMPERATURE;
event->timestamp = millis();
event->temperature = _theBMP280->readTemperature();
return true;
}
/**************************************************************************/
/*!
@brief Gets the sensor_t data for the BMP280's pressure sensor
*/
/**************************************************************************/
void Adafruit_BMP280_Pressure::getSensor(sensor_t *sensor) {
/* Clear the sensor_t object */
memset(sensor, 0, sizeof(sensor_t));
/* Insert the sensor name in the fixed length char array */
strncpy(sensor->name, "BMP280", sizeof(sensor->name) - 1);
sensor->name[sizeof(sensor->name) - 1] = 0;
sensor->version = 1;
sensor->sensor_id = _sensorID;
sensor->type = SENSOR_TYPE_PRESSURE;
sensor->min_delay = 0;
sensor->min_value = 300.0; /* 300 ~ 1100 hPa */
sensor->max_value = 1100.0;
sensor->resolution = 0.012; /* 0.12 hPa relative */
}
/**************************************************************************/
/*!
@brief Gets the pressure as a standard sensor event
@param event Sensor event object that will be populated
@returns True
*/
/**************************************************************************/
bool Adafruit_BMP280_Pressure::getEvent(sensors_event_t *event) {
/* Clear the event */
memset(event, 0, sizeof(sensors_event_t));
event->version = sizeof(sensors_event_t);
event->sensor_id = _sensorID;
event->type = SENSOR_TYPE_PRESSURE;
event->timestamp = millis();
event->pressure = _theBMP280->readPressure() / 100; // convert Pa to hPa
return true;
}