NXP/Freescale MAG3110 3-axis magnetometer. No standalone GROVE unit exists; it is the magnetometer on the original (2017) classic M5Stack Gray (paired with an MPU6050). It sits directly on the host I2C bus at 0x0E (no aux bypass needed, unlike the MPU9250's AK8963). More...

#include <unit_mag3110.hpp>

Inheritance diagram for m5::unit::UnitMAG3110:

Classes
struct	config_t
	Settings for begin() More...

Public Member Functions
	UnitMAG3110 (const uint8_t addr=DEFAULT_ADDRESS)
	Construct with the I2C address the chip will answer on.

virtual	~UnitMAG3110 ()
	Destructor.

virtual bool	begin () override
	Begin the unit.

virtual void	update (const bool force=false) override
	Update the unit.

Settings
config_t	config () const
	Gets the configuration.

void	config (const config_t &cfg)
	Set the configuration.

Reset
bool	softReset ()
	Soft reset (the MAG3110 has no reset command; returns to STANDBY via REG_CTRL_REG1), leaving the chip initialized but unconfigured and stopped.

Measurement setting (stop periodic measurement first)
bool	writeDataRate (const mag3110::DataRate rate, const mag3110::OverSampling os)
	Write the output data rate and over sampling ratio.

bool	readDataRate (mag3110::DataRate &rate, mag3110::OverSampling &os)
	Read the output data rate and over sampling ratio.

Periodic measurement
bool	startPeriodicMeasurement (const mag3110::DataRate rate, const mag3110::OverSampling os)
	Start periodic measurement (auto magnetic reset + continuous ACTIVE)

bool	startPeriodicMeasurement ()
	Start periodic measurement in the current settings.

bool	stopPeriodicMeasurement ()
	Mark periodic measurement as stopped (bookkeeping only; the chip stays in ACTIVE – call sleep() to drop to STANDBY for actual quiescence)

Power
bool	sleep () override
	Enter STANDBY mode (REG_CTRL_REG1 AC cleared)

bool	wakeup () override
	Leave STANDBY.

IMUDataSource
virtual m5::imu::Capability	imuSpec () const override
	Capability of this unit.

virtual m5::imu::Capability	readImuRaw (m5::imu::imu_raw_data_t &out) override
	Read the latest raw IMU data.

virtual void	imuConvertParam (m5::imu::imu_convert_param_t &out) const override
	Gets the conversion parameters for raw IMU data.

Protected Member Functions
bool	start_periodic_measurement (const mag3110::DataRate rate, const mag3110::OverSampling os)

bool	start_periodic_measurement ()

bool	stop_periodic_measurement ()

bool	read_measurement (mag3110::Data &d)

	M5_UNIT_COMPONENT_PERIODIC_MEASUREMENT_ADAPTER_HPP_BUILDER (UnitMAG3110, mag3110::Data)

Detailed Description

NXP/Freescale MAG3110 3-axis magnetometer. No standalone GROVE unit exists; it is the magnetometer on the original (2017) classic M5Stack Gray (paired with an MPU6050). It sits directly on the host I2C bus at 0x0E (no aux bypass needed, unlike the MPU9250's AK8963).

Constructor & Destructor Documentation

◆ UnitMAG3110()

m5::unit::UnitMAG3110::UnitMAG3110 ( const uint8_t addr = DEFAULT_ADDRESS )

explicit

Construct with the I2C address the chip will answer on.

Parameters

[in] addr I2C address (defaults to the chip's factory address)

Member Function Documentation

◆ imuConvertParam()

void m5::unit::UnitMAG3110::imuConvertParam ( m5::imu::imu_convert_param_t & out ) const

overridevirtual

Gets the conversion parameters for raw IMU data.

Parameters

[out] out Destination for the scale factors this driver applies

Implements m5::imu::IMUDataSource.

◆ imuSpec()

virtual m5::imu::Capability m5::unit::UnitMAG3110::imuSpec ( ) const

inlineoverridevirtual

Capability of this unit.

Returns: Mag (no temperature output exposed)

Implements m5::imu::IMUDataSource.

◆ readDataRate()

bool m5::unit::UnitMAG3110::readDataRate	(	mag3110::DataRate &	rate,
		mag3110::OverSampling &	os )

Read the output data rate and over sampling ratio.

Parameters

[out]	rate	Output data rate
[out]	os	Over sampling ratio

Returns: True if successful

Note: Decoded from REG_CTRL_REG1, so it works while measuring as well as while stopped

◆ readImuRaw()

Capability m5::unit::UnitMAG3110::readImuRaw ( m5::imu::imu_raw_data_t & out )

overridevirtual

Read the latest raw IMU data.

Parameters

[out] out Destination buffer filled with the most recent sample

Returns: Capability of the sample (which axes were populated)

Implements m5::imu::IMUDataSource.

◆ sleep()

bool m5::unit::UnitMAG3110::sleep ( )

overridevirtual

Enter STANDBY mode (REG_CTRL_REG1 AC cleared)

Returns: True if successful

Works while periodic measurement is running: it is stopped first, since a standby chip produces no data. STANDBY is the MAG3110's low-power state.

Reimplemented from m5::imu::IMUDataSource.

◆ softReset()

bool m5::unit::UnitMAG3110::softReset ( )

Soft reset (the MAG3110 has no reset command; returns to STANDBY via REG_CTRL_REG1), leaving the chip initialized but unconfigured and stopped.

Returns: True if successful

Warning: During periodic measurements, an error is returned; call stopPeriodicMeasurement() first; Measurement stops and settings must be reapplied; call startPeriodicMeasurement() to reconfigure and resume measurement

◆ startPeriodicMeasurement() [1/2]

bool m5::unit::UnitMAG3110::startPeriodicMeasurement ( )

Start periodic measurement in the current settings.

Returns: True if successful

◆ startPeriodicMeasurement() [2/2]

bool m5::unit::UnitMAG3110::startPeriodicMeasurement	(	const mag3110::DataRate	rate,
		const mag3110::OverSampling	os )

Start periodic measurement (auto magnetic reset + continuous ACTIVE)

Parameters

[in]	rate	Output data rate
[in]	os	Over sampling ratio

Returns: True if successful

◆ stopPeriodicMeasurement()

bool m5::unit::UnitMAG3110::stopPeriodicMeasurement ( )

Mark periodic measurement as stopped (bookkeeping only; the chip stays in ACTIVE – call sleep() to drop to STANDBY for actual quiescence)

Returns: True on success

◆ update()

void m5::unit::UnitMAG3110::update ( const bool force = false )

overridevirtual

Update the unit.

Parameters

[in] force Forces an update if true, even if not time for periodic measurement

◆ wakeup()

bool m5::unit::UnitMAG3110::wakeup ( )

overridevirtual

Leave STANDBY.

Returns: True (always)

No-op by design: on the MAG3110 STANDBY is also the state the chip has to be in to be configured, so there is nothing to undo here. Call startPeriodicMeasurement() to enter ACTIVE continuous measurement.

Reimplemented from m5::imu::IMUDataSource.

◆ writeDataRate()

bool m5::unit::UnitMAG3110::writeDataRate	(	const mag3110::DataRate	rate,
		const mag3110::OverSampling	os )

Write the output data rate and over sampling ratio.

Parameters

[in]	rate	Output data rate
[in]	os	Over sampling ratio

Returns: True if successful

Applied to the chip immediately, and to the periodic measurement interval

Warning: Fails while periodic measurement is running. Every REG_CTRL_REG1 field except AC can only be changed in STANDBY, and a write attempted in ACTIVE is silently ignored rather than reported – so this drops the chip to STANDBY itself instead of trusting inPeriodic(), which says nothing about AC (stopPeriodicMeasurement() leaves the chip running by design; sleep() is what stops it)

Note: The datasheet notes the first output period after leaving STANDBY reads slightly off

Classes

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ UnitMAG3110()

Member Function Documentation

◆ imuConvertParam()

◆ imuSpec()

◆ readDataRate()

◆ readImuRaw()

◆ sleep()

◆ softReset()

◆ startPeriodicMeasurement() [1/2]

◆ startPeriodicMeasurement() [2/2]

◆ stopPeriodicMeasurement()

◆ update()

◆ wakeup()

◆ writeDataRate()