bmp280

README

BMP280

A golang implementation for using the BMP280 temperature / pressure sensor via i2c using the Periph.io libraries

Documentation

Index

• Constants
• type BMP
  • func NewBMP280(dev *i2c.Dev) (*BMP, error)
  • func NewBMP280WithConfig(dev *i2c.Dev, cfg *Configuration) (*BMP, error)
  • func (me *BMP) Configuration() *Configuration
  • func (me *BMP) Init() error
  • func (me *BMP) ReadAll() (float64, float64, error)
  • func (me *BMP) ReadPressure() (float64, error)
  • func (me *BMP) ReadTemperature() (float64, error)
  • func (me *BMP) Reset() error
  • func (me *BMP) SetConfiguration(cfg *Configuration) error
• type Configuration
  • func ConfigDefault() *Configuration
  • func ConfigHighSpeed() *Configuration
  • func ConfigLowPower() *Configuration
• type FilteringCoefficient
• type Oversampling
• type PowerMode
• type StandbyTime

Constants

const (
	// AddressDefault the default I2C address BMP280 uses when the SDO pin is grounded
	AddressDefault uint8 = 0x76

	// AddressLegacy the default I2C address for BMP180. BMP280 can also have this I2C address when SDO pin is connected to Vddio
	AddressLegacy uint8 = 0x77
)

Types

type BMP

type BMP struct {
	// contains filtered or unexported fields
}

BMP a BMP280 sensor

func NewBMP280

func NewBMP280(dev *i2c.Dev) (*BMP, error)

NewBMP280 create an initialize a new BMP280 sensor. Returns the newly created BMP280 sensor

func NewBMP280WithConfig

func NewBMP280WithConfig(dev *i2c.Dev, cfg *Configuration) (*BMP, error)

NewBMP280WithConfig create an initialize a new BMP280 sensor and set up its initial configuration. Returns the newly created BMP280 sensor or any errors that occurred when configuring it.

func (*BMP) Configuration

func (me *BMP) Configuration() *Configuration

Configuration get the current configuration for this BMP280 sensor

func (*BMP) Init

func (me *BMP) Init() error

Init initializes the BMP280 sensor with calibration data saved in the BMP280's registers

func (*BMP) ReadAll

func (me *BMP) ReadAll() (float64, float64, error)

ReadAll reads both temperature and pressure sensor data at once. Returns temperature value, pressure value, or any errors that occurred

func (*BMP) ReadPressure

func (me *BMP) ReadPressure() (float64, error)

ReadPressure read the latest pressure reading from the BMP280. Returns the pressure in Pascals or any i2c errors that occurred

func (*BMP) ReadTemperature

func (me *BMP) ReadTemperature() (float64, error)

ReadTemperature read the latest temperature reading from the BMP280. Returns the temperature in Celsius or any i2c errors that occurred

func (*BMP) Reset

func (me *BMP) Reset() error

Reset perform a full reset on the BMP280 device as if it had first powered on

func (*BMP) SetConfiguration

func (me *BMP) SetConfiguration(cfg *Configuration) error

SetConfiguration set up the configuration for how this BMP280 sensor should operate. Returns any errors that occur when configuring the sensor

type Configuration

type Configuration struct {
	StandbyTime             StandbyTime
	IIRFiltering            FilteringCoefficient
	TemperatureOversampling Oversampling
	PressureOversampling    Oversampling
	Mode                    PowerMode
}

Configuration additional configuration options for the BMP280 sensor

func ConfigDefault

func ConfigDefault() *Configuration

ConfigDefault returns a default configuration for the BMP280 sensor. This configuration offers a decent compromise between power consumption, resolution, and responsiveness

func ConfigHighSpeed

func ConfigHighSpeed() *Configuration

ConfigHighSpeed returns a configuration for low resolution, high speed (~125 Hz refresh rate), high power consumption applications.

func ConfigLowPower

func ConfigLowPower() *Configuration

ConfigLowPower returns a configuration for low resolution, low speed, ultra-low power consumption applications

type FilteringCoefficient

type FilteringCoefficient uint8

FilteringCoefficient options for filtering data to smooth sudden spikes in sensor readings

const (
	// FilteringOff no filtering. Each value is the last raw value read from the sensor
	FilteringOff FilteringCoefficient = 0x00

	// Filtering2 Slight filtering. Takes about 2 samples to start seeing significant changes in sensor values
	Filtering2 FilteringCoefficient = 0x02

	// Filtering4 Some filtering. Takes about 5 samples to start seeing significant changes in sensor values
	Filtering4 FilteringCoefficient = 0x03

	// Filtering8 High filtering. Takes about 11 samples to start seeing significant changes in sensor values
	Filtering8 FilteringCoefficient = 0x04

	// Filtering16 Very high filtering. Takes about 22 samples to start seeing significant changes in sensor values
	Filtering16 FilteringCoefficient = 0x05
)

type Oversampling

type Oversampling uint8

Oversampling defines how much sampling do to for a measurement. Higher sampling means higher precision, but slower measurement speeds

const (
	// OversampleSkip skip this measurement
	OversampleSkip Oversampling = 0x00

	// OversampleX1 16 bit resolution (2.62 Pa or 0.0050 C)
	OversampleX1 Oversampling = 0x01

	// OversampleX2 17 bit resolution (1.31 Pa or 0.0025 C)
	OversampleX2 Oversampling = 0x02

	// OversampleX4 18 bit resolution (0.66 Pa or 0.0012 C)
	OversampleX4 Oversampling = 0x03

	// OversampleX8 19 bit resolution (20.33 Pa or 0.0006 C)
	OversampleX8 Oversampling = 0x04

	// OversampleX16 20 bit resolution (0.16 Pa or 0.0003 C)
	OversampleX16 Oversampling = 0x05
)

type PowerMode

type PowerMode uint8

PowerMode indicates what power mode the BMP sensor should operate in

const (
	// ModeSleep No measurements are performed. Power consumption is at a minimum. All registers are accessible
	ModeSleep PowerMode = 0x00

	// ModeForced Single measurements are performed according to the select measurement and filter options. Sensor returns to sleep mode after measurement.
	ModeForced PowerMode = 0x01

	// ModeNormal Continuously cycles between an active measurement period and inactive standby period (defined by Standby Time).
	ModeNormal PowerMode = 0x03
)

type StandbyTime

type StandbyTime uint8

StandbyTime defines how long between measurements during NormalMode operation

const (
	// Standby500u 500 microseconds
	Standby500u StandbyTime = 0x00

	// Standby062 62.5 milliseconds
	Standby062 StandbyTime = 0x01

	// Standby125 125 milliseconds
	Standby125 StandbyTime = 0x02

	// Standby250 250 milliseconds
	Standby250 StandbyTime = 0x03

	// Standby500 500 milliseconds
	Standby500 StandbyTime = 0x04

	// Standby1s 1 second
	Standby1s StandbyTime = 0x05

	// Standby2s 2 seconds
	Standby2s StandbyTime = 0x06

	// Standby4s 4 seconds
	Standby4s StandbyTime = 0x07
)