MMC35240 Class Reference

MMC35240 Tri-axis Magnetic Sensor API. More...

Detailed Description

• ID: mmc35240
• Name: MMC35240 Tri-axis Magnetic Sensor
• Category: compass
• Manufacturer: Memsic
• Connection: iio i2c

The MMC3524xPJ is a complete 3-axis magnetic sensor

    // Instantiate a MMC35240 Magnetic Sensor on iio device 5. This configuration is a reference and
    // should be changed per platform/board type.
    magnetometer = new upm::MMC35240(5);
    // Kernel driver does not allow changing the value of scale at run-time, default scale is
    // 0.001000
    magnetometer->setScale(0.001000);
    // Available sampling frequency are 1.5, 13, 25, 50
    magnetometer->setSamplingFrequency(25.000000);
    magnetometer->enable3AxisChannel();
    magnetometer->installISR(data_callback, NULL);
    magnetometer->enableBuffer(16);

    while (shouldRun) {
        sleep(1);
    }
    magnetometer->disableBuffer();

Data Structures
struct	compass_cal_t
struct	filter_average_t

Public Types
typedef double	mat_input_t [MAGN_DS_SIZE][3]

Public Member Functions
	MMC35240 (int device)
	~MMC35240 ()
void	installISR (void(*isr)(char *), void *arg)
int64_t	getChannelValue (unsigned char *input, mraa_iio_channel *chan)
bool	enableBuffer (int length)
bool	disableBuffer ()
bool	setScale (const float scale)
bool	setSamplingFrequency (const float sampling_frequency)
bool	enable3AxisChannel ()
void	extract3Axis (char *data, float *x, float *y, float *z)
int	getCalibratedLevel ()
void	initCalibrate ()
void	getCalibratedData (int *cal_level, double offset[3][1], double w_invert[3][3], double *bfield)
void	loadCalibratedData (int cal_level, double offset[3][1], double w_invert[3][3], double bfield)

Constructor & Destructor Documentation

MMC35240

(

int

device

)

MMC35240 Tri-axis Magnetic Sensor

Parameters

device

iio device number

~MMC35240

(

)

MMC35240 destructor

Member Function Documentation

void installISR	(	void(*)(char *)	isr,
		void *	arg
	)

Installs an interrupt service routine (ISR) to be called when an interrupt occurs

Parameters

isr	Pointer to a function to be called on interrupt
arg	Pointer to an object to be supplied as an argument to the ISR.

int64_t getChannelValue	(	unsigned char *	input,
		mraa_iio_channel *	chan
	)

Extract the channel value based on channel type

Parameters

input	Channel data
chan	MRAA iio-layer channel info

bool enableBuffer

(

int

length

)

Enable trigger buffer

Parameters

length

buffer length in integer

bool disableBuffer

(

)

Disable trigger buffer

bool setScale

(

const float

scale

)

Set scale

Parameters

scale

in float Kernel driver does not support changing the value of scale on run-time Default scale is 0.001000

bool setSamplingFrequency

(

const float

sampling_frequency

)

Set sampling frequency

Parameters

sampling_frequency

sampling frequency in float Available sampling frequency are 1.5, 13, 25, 50 Default sampling frequency is 1.500000

bool enable3AxisChannel

(

)

Enable 3 axis scan element

void extract3Axis	(	char *	data,
		float *	x,
		float *	y,
		float *	z
	)

Process enabled channel buffer and return x, y, z axis

Parameters

data	Enabled channel data, 6 bytes, each axis 2 bytes
x	X-Axis
y	Y-Axis
z	Z-Axis

int getCalibratedLevel

(

)

Get calibrated level

void initCalibrate

(

)

Reset calibration data and start collect calibration data again

void getCalibratedData	(	int *	cal_level,
		double	offset[3][1],
		double	w_invert[3][3],
		double *	bfield
	)

Get calibrated data

void loadCalibratedData	(	int	cal_level,
		double	offset[3][1],
		double	w_invert[3][3],
		double	bfield
	)

Load calibrated data

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The documentation for this class was generated from the following files:

• src/mmc35240/mmc35240.hpp
• src/mmc35240/mmc35240.cxx