Projects:2017s2-225 Digital Microphone Array using MEMS Microphones

Project Team

Students

• XingYang Gan
• Xue Han

Supervisors

• Brian Ng
• Hong Gunn Chew
• (MechEng)Carl Howard

Introduction

The project is one of the electrical and electronic section from another project of The University of Adelaide. The purpose of another project is to understand the sound refraction trough hot Exhaust Flows. Hence, the purpose of this project is to build a system by implementing the MEMS microphone arrays that able to collect the data of the signal flows. In addition, the system able to store all the data about the amplitude of the sound. After the comprise of the data from the numerous of digital microphone, the system have the capability to send the data to a host computer.

Aim

The Aim of project is to design, build and test a system by implementing the digital MEMS microphone array.

Goals

• Implement the digital microphone which comprise more than 64 channels.
• Design and build a system which able to comprise numerous of MEMS microphone and able to collect and store the data.
• Build a system able to send the data to host computer.

Motivation

After the invention of the technology of MEMS, the technology successfully reduces the physical dimension of the particular devices such as MEMS microphone. Hence, the new system of MEMS microphone array will be made with a lower size and lower cost. On the other hand, as mention on the background, this project is one of another section from other’s project, after the system collect and store the data, the user will take over the data for analyzing.

Requirement

• The system is capable to handle more than 64 MEMS microphones.
• The output of the signal should be multi-channel files
• The data sampling rate required 48kHz.
• The data capture duration at least 3 minutes.
• The handle sound pressure up to 120 dB re 20 micro-Pa.
• The system able to handle at least on temperature on 60 degree

===Technical Challange There are several technical challenges in this project. Firstly, due to the numerous of the microphone receiving channel, it will collect a huge data stream. Therefore, the internal data storage obviously is not enough to store more than 3 minutes’ data. Hence, the designer needs to design an algorithm to the system which able to receive and sending the data to computer together that able to prevent the data overflow on the controller. Therefore, the timing of the controller is the core issues in this project. Secondly, the dimension of the designed microphone PCB board is another one of the challenges of this project. In the last testing platform, the 64 microphones will be implemented along the two-meter length. Therefore, the dimension of the PCB board could not bigger than 3cm. Lastly, besides from the dimension of the PCB board, the circuit design of the microphone PCB is another challenge in this project. The microphone is one of the high sensitive component, the design of the PCB will keep testing to find out the best circuit design that with low noise signal input. It might take a long time to try and error while designing the PCB board.