brltty

brltty [-a level] [-b device] [-d table] [-e] [-k device] [-l port] [-M model] [-n] [-s driver] [-t table] [-v level] [--] [driver-args...]

-a level
    Set audio volume level (0-100)

-b device
    Braille display device path (e.g. usb:, bluetooth:)

-d table
    Braille driver code or table name

-e
    Enable speech support

-k device
    Braille keyboard input device path

-l port
    Serial port device for braille display

-M model
    Braille display model name

-n
    Do not daemonize (run in foreground)

-s driver
    Speech synthesizer driver code

-t table
    Text translation table

-v level
    Set verbosity level (0-9)

-V
    Print version information

--
    End of brltty options, following are driver args

Brltty is a background process (daemon) that provides access to the Linux console (when in text mode) for a blind person using a refreshable braille display. It drives the braille display through a serial port, USB, or Bluetooth.

Brltty supports dozens of braille displays from various vendors and handles features like cells, rotors, cursor routing keys, and status cells. It also supports speech synthesis drivers for text-to-speech output and can handle keyboard input via braille keyboard.

The daemon automatically starts at boot via systemd or init scripts and runs with elevated privileges to access hardware. Configuration is done via /etc/brltty.conf, specifying drivers, devices, and tables for braille, text translation, and attributes.

Brltty is essential for console-based work in text environments, servers, or recovery modes, enabling full screen reader functionality without a graphical desktop.

Requires root privileges or setuid to access hardware devices. Conflicts with X11 console access; use with text consoles only. Some drivers need kernel modules (e.g. usbserial). Bluetooth support varies by distro.

Main config in /etc/brltty.conf: e.g. brltty usb:, speechdrv espeak

Run brltty -V or brltty -d list for supported braille/speech drivers

Developed by Dave Mielke since 1995; first release around 2001. Actively maintained with support for 70+ braille models and 20+ speech drivers as of 2024. Key milestone: USB support in 2003.

espeakup(8), speech-dispatcher(1), pactl(1)