Using LIS2DW12TR to implement acceleration function in wireless headphones

LIS2DW12 is an ultra-low power 3D accelerate sensor in ST's second-generation MEMS family. It is often used in miniaturized wearable products such as rings and headphones. Among them, implanting 3D sensors in earbuds has been a functional trend for Bluetooth headsets in recent years.

The main functions of 3D sensor in headphones are:

1. User posture detection (in the sleeping headset, it also assists in detecting the user's turning over, assessing the sleeping condition, and cooperating with Dolby Surround)
2. Headphone single-double-click function (song switching, play/pause)
3. Enter/exit low power mode (detect whether the headset is stationary)

ST has a complete set of DEMO boards and UNICO tools to assist developers in developing 3D sensors:

STEVAL-MKI109V3 - ST MEMS adapter motherboard, using STM32F401VE MCU, built-in complete software program, MEMS configuration, data interaction, power consumption evaluation, interrupt detection and other functions, and compatible with all ST MEMS sensors

STEVAL-MKI179V1——LIS2DW12 standard 24pin development board, on which is a LIS2DW12 and its minimum system circuit, plugged into STEVAL-MKI109V3 to realize a complete hardware system.

ST UNICO-GUI is an open source host computer software with graphical and interface design, which allows users to intuitively configure MEMS and obtain data and waveforms.

Select target development board

Interface Introduction

3D data real-time waveform

3D acceleration real-time value update

Data in FIFO register

Interrupt function verification (including wake-up, fall, single and double click events, etc.)

►Scenario application diagram

► Display board photos

►Solution Block Diagram

►Core technology advantages

1. Complete software package supports all MEMS evaluation boards 2. Visual interface configuration, supports Linux/ Mac OS X / Windows system development 3. Convenient sensor setting, register configuration, data logging and drawing, can guide engineers to develop faster

►Solution Specifications

• Ultra-low power consumption: 50nA in power-down mode, less than 1µA in active low-power mode • Very low noise: RMS as low as 1.3 mg in low-power mode • Multiple operating modes, multiple bandwidths • Android stationary detection, motion detection • Supply voltage, 1.62 V to 3.6 V • Independent IO power supply • ±2g/±4g/±8g/±16g selectable range • High-speed I²C/SPI digital output interface • Single data conversion on demand • 16-bit data output • Embedded temperature sensor • Self-test • 32-level FIFO • 10000 g high shock survivability • Compliant with ECOPACK, RoHS and “Green” standards