How this is done? Data over audio tones

[ku637]

Hello,

I was curious about an wireless ip camera feature. Once we input the wifi password in the android application it is ( i suppose) transferring this password to camera over audio tones. So next time onwards the camera will automatically connect to your wifi.

h***s://youtu.be/e9jVThItb2U?t=311

Is there any idea how it is achieved? May be im not familiar with it, is it possible to just use a speaker in your android app and generate tones ( or is there is any standard behind it), which can be received by a microphone and by an ordinary MCU to detect the tone frequency?

If any information how this is achieved, it will be nice to know.

Thank you

 

[KlausST]

Hi,

Do you know how an analog modem or a FAX works?

If not: Wikipedia or many other documents in the internet will give good explanations.

Klaus

 

[betwixt]

Are you sure it uses audio tones?

The connection is WiFi so it would be very unusual to send anything by audio tones when a high speed data connection is already available. It is far more likely it uses some data command to set the new password.

Brian.

 

[vivekroy]

I am not sure whether audio tones are used or not, but it can be done quite easily.
We had to transmit an image over audio channels using OFDM modulation and de-modulation as part of our DSP project in school. You are more than welcome to look at the project documents available in https://homes.esat.kuleuven.be/~dspuser/DSP-CIS/2017-2018/material.html

 

[ZASto]

If you have enabled tone for "keyboard" on your smartphone, YOU will hear audio tones.
Transmitted data is purely in digital domain.