API for the BMP280 Digital Pressure Sensor. More...

Detailed Description

ID: bmp280
Name: Digital Pressure Sensor
Category: pressure
Manufacturer: bosch adafruit
Connection: i2c spi gpio
Link: https://www.adafruit.com/products/2651

The BMP280 is an absolute barometric pressure sensor especially designed for mobile applications. The sensor module is housed in an extremely compact 8-pin metal-lid LGA package with a footprint of only 2.0 * 2.5 mm2 and 0.95 mm package height. Its small dimensions and its low power consumption of 2.7 uA @1Hz allow the implementation in battery driven devices such as mobile phones, GPS modules or watches.

As the successor to the widely adopted BMP180, the BMP280 delivers high performance in all applications that require precise pressure measurement. The BMP280 operates at lower noise, supports new filter modes and an SPI interface within a footprint 63% smaller than the BMP180.

    // Instantiate a BMP280 instance using default i2c bus and address
    upm::BMP280 sensor;
    // For SPI, bus 0, you would pass -1 as the address, and a valid pin for CS:
    // BMP280(0, -1, 10);
    while (shouldRun) {
        // update our values from the sensor
        sensor.update();
        // we show both C and F for temperature
        cout << "Compensation Temperature: " << sensor.getTemperature() << " C / "
             << sensor.getTemperature(true) << " F" << endl;
        cout << "Pressure: " << sensor.getPressure() << " Pa" << endl;
        cout << "Computed Altitude: " << sensor.getAltitude() << " m" << endl;
        cout << endl;
        upm_delay(1);
    }

Public Member Functions
	BMP280 (int bus=BMP280_DEFAULT_I2C_BUS, int addr=BMP280_DEFAULT_ADDR, int cs=-1)

virtual	~BMP280 ()

virtual void	update ()

uint8_t	getChipID ()

void	reset ()

float	getTemperature (bool fahrenheit=false)

float	getPressure ()

void	setSeaLevelPreassure (float seaLevelhPA=1013.25)

float	getAltitude ()

virtual void	setUsageMode (BMP280_USAGE_MODE_T mode)

void	setOversampleRateTemperature (BMP280_OSRS_T_T rate)

void	setOversampleRatePressure (BMP280_OSRS_P_T rate)

void	setTimerStandby (BMP280_T_SB_T tsb)

void	setFilter (BMP280_FILTER_T filter)

void	setMeasureMode (BMP280_MODES_T mode)

const char *	getModuleName ()

int	getTemperatureCelsius ()

int	getPressurePa ()

Protected Member Functions
uint8_t	getStatus ()

uint8_t	readReg (uint8_t reg)

int	readRegs (uint8_t reg, uint8_t *buffer, int len)

void	writeReg (uint8_t reg, uint8_t val)

Protected Attributes
bmp280_context	m_bmp280

Constructor & Destructor Documentation

BMP280	(	int	bus = `BMP280_DEFAULT_I2C_BUS`,
		int	addr = `BMP280_DEFAULT_ADDR`,
		int	cs = `-1`
	)

BMP280 constructor.

This driver supports both the BMP280 and the BME280. The BME280 adds a humidity sensor. The device type is detected automatically by querying the chip id register.

This device can support both I2C and SPI. For SPI, set the addr to -1, and specify a positive integer representing the Chip Select (CS) pin for the cs argument. If you are using a hardware CS pin, then you can connect the proper pin to the hardware CS pin on your MCU and supply -1 for cs. The default operating mode is I2C.

Parameters

bus	I2C or SPI bus to use.
addr	The I2C address for this device. Use -1 for SPI.
cs	The gpio pin to use for the SPI Chip Select. Use -1 for I2C, or for SPI with a hardware controlled pin.

Exceptions

std::runtime_error on failure.

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~BMP280 ( )

virtual

BMP280 Destructor.

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Member Function Documentation

void update ( void )

virtual

Update the internal stored values from sensor data.

Exceptions

std::runtime_error on failure.

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uint8_t getChipID ( )

Return the chip ID.

Returns: The chip ID (BMP280_CHIPID).

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void reset ( )

Reset the sensor, as if by a power-on-reset.

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float getTemperature ( bool fahrenheit = false )

Return the current measured temperature. Note, this is not ambient temperature - this is the temperature used to fine tune the pressure measurement. update() must have been called prior to calling this method.

Parameters

fahrenheit true to return data in Fahrenheit, false for Celicus. Celsius is the default.

Returns: The temperature in degrees Celsius or Fahrenheit.

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float getPressure ( )

Return the current measured pressure in Pascals (Pa). update() must have been called prior to calling this method.

Returns: The pressure in Pascals (Pa).

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void setSeaLevelPreassure ( float seaLevelhPA = 1013.25 )

Set the pressure at sea level in hecto-Pascals (hPA). This value is used to compute the altitude based on the pressure. At driver initialization time, this value is set to 1013.25 hPA.

Parameters

seaLevelhPA The pressure at sea level in hectoPascals (hPa). The default is 1013.25 hPA, (101325 Pa).

Returns: The computed altitude in meters.

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float getAltitude ( )

Return the current computed altitude in meters. update() must have been called prior to calling this method.

Returns: The computed altitude in meters.

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void setUsageMode ( BMP280_USAGE_MODE_T mode )

virtual

Set a general usage mode. This function can be used to configure the filters and oversampling for a particular use case. These setting are documented in the BMP280 datasheet. The default mode set in the constructor is USAGE_MODE_INDOOR_NAV, the highest resolution mode.

Parameters

mode	One of the BMP280_USAGE_MODE_T values.

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void setOversampleRateTemperature ( BMP280_OSRS_T_T rate )

Set the temperature sensor oversampling parameter. See the data sheet for details. This value can be automatically set to a suitable value by using one of the predefined modes for setUsageMode().

Parameters

rate	One of the BMP280_OSRS_T_T values.

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void setOversampleRatePressure ( BMP280_OSRS_P_T rate )

Set the pressure sensor oversampling parameter. See the data sheet for details. This value can be automatically set to a suitable value by using one of the predefined modes for setUsageMode().

Parameters

rate	One of the BMP280_OSRS_P_T values.

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void setTimerStandby ( BMP280_T_SB_T tsb )

Set the timer standby value. When in NORMAL operating mode, this timer governs how long the chip will wait before performing a measurement. See the data sheet for details.

Parameters

tsb	One of the BMP280_T_SB_T values.

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void setFilter ( BMP280_FILTER_T filter )

Set the IIR filtering parameter. See the data sheet for details. This value can be automatically set to a suitable value by using one of the predefined modes for setUsageMode().

Parameters

filter One of the BMP280_FILTER_T values.

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void setMeasureMode ( BMP280_MODES_T mode )

Set the default measuring mode. Basic values are forced, sleep, and normal. See the data sheet for details. This value can be automatically set to a suitable value by using one of the predefined modes for setUsageMode().

Parameters