Intro

 

It is easy to hear broadcasting from a large building such as a department store or a mart.

If I use this broadcasting at home, no need to make my voice too louder.

 

 

STEP 1. Introducing the Voice Streaming

We are going to introduce a project that allows you to send voices over Ethernet and listen.

If this device is in a home with children, their mother does not need to make her voice louder.

Follow the link below for more details.

https://www.hackster.io/maker_leo/ethernet-voice-streaming-59e03e

 

 

STEP 2. Materials

2-1 WIZwiki-W7500: 2 pieces (since you need to use transmit and receive)

http://shop.wiznet.co.kr/front/contents/product/view.asp?cateid=47&pid=1254

 

0

 

2-2. Microphone

https://developer.mbed.org/components/Electret-Microphone-Amplifier-MAX9814/

1

 

 

2-3 Speaker

Any speakers don’t matter. Speakers always use two lines.

2

 

2-4. RC

R : 2.7Kohm / C : 0.01uF

Use the following two components to create an RC low pass filter.

This is an apparatus for improving sound quality.

 

3

 

 

2-5 Compiler

Mbed(web compiler)

https://developer.mbed.org/

 

STEP 3. Hardware Configuration

4

5

 

6

6

 

Figure 1 Implement PC lowpass filter

 

 

STEP 4. Source code link and key code description

Download the code from the link below first.

https://os.mbed.com/teams/WIZnet/code/Ethernet_Voice_Streaming/

Since we are going to use the UDP protocol, we need to make a few modifications regarding UDP.

8

 

Figure 2 Server 와 Client setting( Server : Receive data, Client :  Transmission data)

9

Figure 3 Ethernet Setting

10

Figure 4 UDP server Setting

11

Figure 5 UDP Client Setting

12

 

From the Client needs an ADC to process the voice message. At this time, the voice message is stored in the buffer and giving a time of 100u sec.

 

Code 재가공 0

 

Therefore ADC operates every 100u sec.

 

Code 재가공 1

From the Client stores voice messages every 100u sec.

 

Code 재가공 2

A server transmits the voice message by using PWM.

 

Code 재가공 3

The double buffer was used for real time. Another buffer stores data while one buffer is processed as the figure below.

 

13

14

STEP 5. A result of this project

15

 

 

Conclusion

Although it seemed to transmit voice through Ethernet simply in a circuit, we used the RC low pass filter for noise processing and double buffer for real-time transmission.

I hope you have another project that can send and receive voices better in realtime with this project.

 

Curator: irina

Email: ekkim@wiznet.io