C++ API for MPL3115A2 chip (Atmospheric Pressure Sensor) More...

Detailed Description

ID: mpl3115a2
Name: mpl3115a2 Atmospheric Pressure
Category: pressure
Manufacturer: freescale
Link: http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPL3115A2
Connection: i2c

Freescale MPL3115A2 is a high precision, ultra-low power consumption pressure sensor. It has a range of between 50 and 110 kPa.

    float pressure    = 0.0;
    float temperature = 0.0;
    float altitude    = 0.0;
    float sealevel    = 0.0;
    sensor = new upm::MPL3115A2(0, MPL3115A2_I2C_ADDRESS);
    sensor->testSensor();
    while (!doWork) {
        temperature = sensor->getTemperature(true);
        pressure    = sensor->getPressure(false);
        altitude    = sensor->getAltitude();
        sealevel    = sensor->getSealevelPressure();
        std::cout << "pressure value = " <<
                    pressure <<
                    ", altitude value = " <<
                    altitude <<
                    ", sealevel value = " <<
                    sealevel <<
                    ", temperature = " <<
                    temperature << std::endl;
        usleep (500000);
    }

Public Member Functions
	MPL3115A2 (int bus, int devAddr=MPL3115A2_I2C_ADDRESS, uint8_t mode=6)

	~MPL3115A2 ()

int	testSensor (void)

int	resetSensor (void)

void	dumpSensor (void)

int	sampleData (void)

int32_t	getPressureReg (int reg)

int32_t	getTempReg (int reg)

float	getPressure (int bSampleData=true)

float	getTemperature (int bSampleData=true)

float	getSealevelPressure (float altitudeMeters=0.0)

float	getAltitude (float sealevelPressure=101325.0)

void	setOversampling (uint8_t oversampling)

uint8_t	getOversampling (void)

float	getTemperatureMax (void)

float	getTemperatureMin (void)

float	getPressureMax (void)

float	getPressureMin (void)

float	convertTempCtoF (float fTemp)

float	convertPaToinHg (float fPressure)

mraa_result_t	i2cWriteReg (uint8_t reg, uint8_t value)

uint16_t	i2cReadReg_16 (int reg)

uint8_t	i2cReadReg_8 (int reg)

Constructor & Destructor Documentation

MPL3115A2	(	int	bus,
		int	devAddr = `MPL3115A2_I2C_ADDRESS`,
		uint8_t	mode = `6`
	)

Instantiates an MPL3115A2 object

Parameters

bus	number of used bus
devAddr	address of used i2c device
mode	MPL3115A2 oversampling (6 = 64x)

Here is the call graph for this function:

~MPL3115A2 ( )

MPL3115A2 object destructor, basicaly it close i2c connection.

Member Function Documentation

int testSensor ( void )

Test the sensor and try to determine if operating by looking for small variations in the value

Here is the call graph for this function:

int resetSensor ( void )

Perform a soft RESET of the MPL3115A2 device to ensure it is in a known state. This function can be used to reset the min/max temperature and pressure values.

Here is the call graph for this function:

void dumpSensor ( void )

Dump out the i2c register block to stdout

Here is the call graph for this function:

int sampleData ( void )

Initiate a temp/pressure mesasurement and wait for function to complete. The temp and pressure registers can be read after this call.

Here is the call graph for this function:

Here is the caller graph for this function:

int32_t getPressureReg ( int reg )

Read a pressure value from the mpl3115a2 [Pa * 100]

Parameters

reg	base address of pressure register

Here is the call graph for this function:

Here is the caller graph for this function:

int32_t getTempReg ( int reg )

Read a temperature value from the mpl3115a2 [degC * 1000]

Parameters

reg	base address of temperature register

Here is the call graph for this function:

Here is the caller graph for this function:

float getPressure ( int bSampleData = true )

Read the current pressure value from the mpl3115a2 [Pa]

Parameters

bSampleData Set non-zero to sample reading

Here is the call graph for this function:

Here is the caller graph for this function:

float getTemperature ( int bSampleData = true )

Read the current temperature value from the mpl3115a2 [degC]

Parameters

bSampleData Set non-zero to sample reading

Here is the call graph for this function:

Here is the caller graph for this function:

float getSealevelPressure ( float altitudeMeters = 0.0 )

Read the current pressure and using a known altitude calculate the sea level pressure value [Pa] This function should be preceeded by the sampleData() call

Parameters

altitudeMeters Altitude in meters

float getAltitude ( float sealevelPressure = 101325.0 )

Read the current pressure and using a known sea level pressure calculate the altitude value [m] This function should be preceeded by the sampleData() call

Parameters

sealevelPressure Current sea level pressure

void setOversampling ( uint8_t oversampling )

Set the oversampling setting (ranges from 0 to 7). The value represents 2^n samples (ranging from 1 to 128). The time to calculate the sample is approximately (2^n * 4 + 2) mS

Parameters

oversampling New oversampling value

Here is the caller graph for this function: