whites11/cough-button

Cough button

This project aims at providing software support for a cheap (normally < 10€) DYI hardware cough button for linux.

A cough button is simply a button that allows to mute and unmute a microphone attached to a linux computer.

Theoretically the computer-side software provided with this repo can be easily extended/replaced to support other operating systems as well. I don't care about any other operating system so I will probably never do it (but feel free to contribute).

Diagram of the components

Hardware

The idea of this project is to act as an easy-to-hack framework and be adaptable to different hardware and potentially different sound systems. Nevertheless it is being developed and (poorly) tested with the following hardware:

• The sketch included in this repo is meant to be flashed on a teensy 2.0 device: https://www.pjrc.com/store/teensy.html
• The button I am personally using is this one but virtually any button can do.

This is the connections diagram:

Concepts

The daemon is a go CLI tool that has to be run from the command line as unprivileged user.

During startup, the deamon:

• looks for a supported serial device to listen inputs from and to post the microphone muted status to.
• connects to pulseaudio via DBUS, setting the mute status and getting notifications about state changes.

The LED of the external device is updated to reflect in near-realtime the muted status of the default source of the system.

WARNING: if you are using custom settings for some applications, cough button will not be able to mute those applications for you. It always mutes the default source.

Getting started

It is still early days for the project, so running it is a manual process.

Hopefully my interest will in the project will continue and/or contributors will join me making it more straightforward.

In any case these are the steps needed to get yourself a cough button.

• Buy the hardware and connect following the connections diagram above.
• Flash the teensy device following the official instructions.
• Run the daemon as unprivileged user (cd into the daemon directory and run go run main.go).