SENSIVIC•2024

ESP32 Acoustic Antenna System

Advanced acoustic localization system using ESP32 and 4 microphones sampling at 100kHz for precise sound source positioning in space

Project Context

Due to the semiconductor shortage, SENSIVIC needed to migrate from STM to ESP32 microcontroller. The project goal was to develop a solution based on ESP32 to create an acoustic antenna capable of sampling 4 microphones at 100 kHz to localize sound sources in 3D space with high precision.

Technical Implementation

ADC Development & Testing

  • •Started with single microphone ADC implementation
  • •Tested and optimized analog-to-digital conversion
  • •Analyzed sampling rates and signal quality
  • •Established baseline performance metrics

DMA Integration for Multi-Channel

  • •Implemented Direct Memory Access (DMA) for simultaneous sampling
  • •Configured 4-channel simultaneous data acquisition
  • •Optimized memory management for high-frequency data
  • •Ensured synchronized sampling across all channels

MEMS Microphone Implementation

  • •Integrated MEMS (micro-electromechanical systems) microphones
  • •Achieved target frequency of 100kHz sampling rate
  • •Implemented i2s protocol for digital audio interface
  • •Optimized signal processing for acoustic localization

Results & Achievements

Successful Migration

Successfully migrated from STM to ESP32 platform

High-Frequency Sampling

Achieved 100kHz sampling rate with MEMS microphones

Multi-Channel Processing

Implemented simultaneous 4-microphone data acquisition

PoC Delivery

Delivered functional Proof of Concept in 2 months

Technologies & Tools

ESP32
C/C++
MEMS
i2s Protocol
DMA
ESP-IDF
Digital Signal Processing
ADC
Real-time Systems

Technical Challenges & Solutions

Key Challenges

  • •Simultaneous sampling of 4 microphones at 100kHz
  • •Memory management for high-frequency data streams
  • •Maintaining synchronization across channels
  • •Real-time processing requirements

Implemented Solutions

  • •DMA implementation for efficient data handling
  • •MEMS microphones for high-frequency capability
  • •i2s protocol for synchronized digital audio
  • •ESP-IDF framework optimization

System Architecture & Applications

Acoustic Localization Principle

Using time difference of arrival (TDOA) between 4 microphones to triangulate sound source position in 3D space with high precision.

Real-time Processing

ESP32 processes audio streams in real-time, calculating spatial coordinates of detected sounds for immediate response applications.

Industrial Applications

Ideal for security systems, industrial monitoring, and automated response systems requiring precise sound source localization.

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