SmartElex BMM150 3 Axis Magnetometer Sensor

Overview

The module is based on the BMM150 3-axis geomagnetic sensor IC, a low-power digital magnetometer designed for magnetic field measurement and compass applications.

• Measures magnetic field along:

  • X-axis

  • Y-axis

  • Z-axis

   

• Detects:

  • Earth's magnetic field

  • External magnetic sources

   

Commonly used for heading (compass), orientation, and magnetic sensing.

Working Principle

Magneto-Resistive Sensing

• Uses anisotropic magnetoresistance (AMR) technology

• Magnetic field changes alters resistance of sensing elements

Signal Processing

• Magnetic field inte changes occur

• Internal circuitry converts signal

• ADC produces digital output values

Output represents magnetic field strength in 3 axes.

Measurement Characteristics

Magnetic Field Range

• Typical measurement range: 1300 T (X/Y)

• 2500 T (Z-axis)

Resolution

• High-resolution digital output (1315 bits typical)

Sensitivity

• Capable of detecting:

  • Weak Earth magnetic field (~2565 T)

  • Strong nearby magnetic sources

   

Electrical Characteristics

• Supply voltage: 1.62V to 3.6V

• Very low power consumption

• Multiple power modes available

Communication Interface

SPI interface

Compatible with most microcontrollers.

Internal Features

Built-in Hall / AMR Front-End

• Accurate magnetic sensing

Offset Compensation

• Internal compensation reduces measurement errors

Temperature Compensation

• Improves stability over temperature changes

Interrupt System

• Can generate interrupts based on:

  • Data ready

  • Threshold conditions

   

Low Power Modes

• Modes include:

  • Sleep

  • Forced

  • Normal

   

Operating Behavior

Magnetic Field Measurement

• Measures both:

  • Static magnetic fields

  • Dynamic field changes

   

ermine heading direction

Orientation Detection

• Combined with accelerometer full orientation sensing

Environmental Characteristics

• Stable across temperature variations

• Suitable for indoor and outdoor use

Limitations

• Sensitive to:

  • Nearby metal objects

  • Electromagnetic interference

   

• Requires calibration for:

  • Accurate compass readings

   

• Cannot measure:

  • Distance directly

   

Typical Pin Configuration

• VCC Power supply

• GND Ground

• SDA / MOSI Data

• SCL / SCK Clock

• CS< Interrupt output

Functional Role

The module acts as a:

• Magnetic field sensor

• Digital compass sensor

• Orientation detection component

Summary

The SmartElex BMM150 Magnetometer is a compact and low-power magnetic sensing module that:

• Measures 3-axis magnetic field (X, Y, Z)

• Uses magneto-resistive sensing technology

• Provides digital output via I2C/SPI

• Offers high sensitivity and low power consumption

• Is optimized for compass and orientation applications