Ultrasound support?

[matthewsanders]

This is a great project! Thank you for sharing!

What would be required to use this library in the inaudible ultrasound range?

I have been evaluating a few different libraries and most provide a way to configure the frequency range and support inaudible communication. They all have down sides, however, so I am trying to find the solution with the most robust implementation and I find qrtone to be promising in this regard.

I would prefer to use the wasm library so if I need to make a custom build I would appreciate any build instructions you may have for this.

Also is there a limit to the payload size that can be sent? I would like to be able to basically send files between devices.

Thank you!!

[nicolas-f]

Hi,

Thanks for your interest in QRTone.

The frequencies are defined in the qrtone.c file, you could use the 16khz-20khz range for mostly inaudible communication.

The transfer rates of data over audio (through air not wires) are quite low (1 byte each 85 ms).
When using data-over-audio, only the "link" should be sent, the receiving phone would use internet in order to download the file content.

There is another library with javascript support:

https://quiet.github.io/quiet-js/