MAG3110 setting enums and measurement data (framework independent) More...

#include <array>
#include <cstdint>
#include <cmath>

Classes
struct	m5::unit::mag3110::Data
	One MAG3110 sample: a 7-byte burst from DR_STATUS (0x00) More...

Namespaces
namespace	m5
	Top level namespace of M5Stack.

Enumerations
enum class	m5::unit::mag3110::DataRate : uint8_t { Rate80Hz , Rate40Hz , Rate20Hz , Rate10Hz , Rate5Hz , Rate2_5Hz , Rate1_25Hz , Rate0_63Hz }
	Output data rate select (REG_CTRL_REG1 DR[7:5]) More...

enum class	m5::unit::mag3110::OverSampling : uint8_t { X16 , X32 , X64 , X128 }
	Over sampling ratio (REG_CTRL_REG1 OS[4:3]) More...

Functions
constexpr uint32_t	m5::unit::mag3110::output_rate_mhz (const DataRate rate, const OverSampling os)
	Effective output rate in milli-Hz.

constexpr uint32_t	m5::unit::mag3110::interval_ms (const DataRate rate, const OverSampling os)
	Sampling interval (ms) for a rate/oversampling pair, rounded up.

constexpr uint8_t	m5::unit::mag3110::ctrl_reg1_active (const DataRate rate, const OverSampling os)
	REG_CTRL_REG1 value entering continuous ACTIVE measurement (FR and TM left at 0)

Variables
constexpr float	m5::unit::mag3110::RAW_UT_PER_LSB {0.10f}
	Native sensitivity (µT per raw LSB); fixed, factory-calibrated.

constexpr float	m5::unit::mag3110::OUTPUT_LSB_PER_UT {16.0f}
	Library-wide magnetometer output scale (raw LSB per µT); see imu_convert_param_t.

Detailed Description

MAG3110 setting enums and measurement data (framework independent)

Enumeration Type Documentation

◆ DataRate

enum class m5::unit::mag3110::DataRate : uint8_t

strong

Output data rate select (REG_CTRL_REG1 DR[7:5])

Each value is named after the output rate it gives at OverSampling::X16, which is how the datasheet labels them (Table 32); a larger oversampling ratio divides that down. DR on its own fixes the ADC rate and with it the supply current, from 900µA at Rate80Hz to 8.6µA at Rate0_63Hz

Enumerator
Rate80Hz	80Hz at X16 (ADC 1280Hz, 900µA)
Rate40Hz	40Hz at X16 (ADC 640Hz, 550µA)
Rate20Hz	20Hz at X16 (ADC 320Hz, 275µA)
Rate10Hz	10Hz at X16 (ADC 160Hz, 137.5µA)
Rate5Hz	5Hz at X16 (ADC 80Hz, 68.8µA)
Rate2_5Hz	2.5Hz at X16 (ADC 80Hz, 34.4µA)
Rate1_25Hz	1.25Hz at X16 (ADC 80Hz, 17.2µA)
Rate0_63Hz	0.63Hz at X16 (ADC 80Hz, 8.6µA)

◆ OverSampling

enum class m5::unit::mag3110::OverSampling : uint8_t

strong

Over sampling ratio (REG_CTRL_REG1 OS[4:3])

OS on its own fixes the noise floor: 0.40µT rms at X16 down to 0.25µT rms at X128. It also divides the output rate, so most output rates are reachable from several DataRate/OverSampling pairs whose current and noise differ widely – 10Hz for instance is available at 900/550/275/137.5µA with 0.25/0.30/0.35/0.40µT rms. That trade-off is why the two fields are exposed separately

Enumerator
X16	16x (0.40µT rms)
X32	32x (0.35µT rms)
X64	64x (0.30µT rms)
X128	128x (0.25µT rms)

Function Documentation

◆ interval_ms()

uint32_t m5::unit::mag3110::interval_ms	(	const DataRate	rate,
		const OverSampling	os )

constexpr

Sampling interval (ms) for a rate/oversampling pair, rounded up.

Note: Rate80Hz + X16 gives 13ms, the interval this driver used when the rate was fixed

◆ output_rate_mhz()

uint32_t m5::unit::mag3110::output_rate_mhz	(	const DataRate	rate,
		const OverSampling	os )

constexpr

Effective output rate in milli-Hz.

Oversampling divides the DataRate's rate, exactly as datasheet Table 32 tabulates it

Classes

Namespaces

Enumerations

Functions