BRLTTY is a daemon for providing access to the Linux / Unix console via braille displays. However, this product may be of interest not only for technically advanced blind users of UNIX-like operating systems, but also for ordinary people using smartphones or tablets on the Android platform. The fact is that BRLTTY has a version in the form of the OS Android accessibility service, which allows, by connecting a braille display, to carry out tactile output precisely through BRLTTY, which in some cases may be a preferable option than BrailleBack or Mobile Accessibility .
At the time of this writing, BRLTTY is not in the Play Market, so its installation package must be downloaded from the developer’s official website. The most recent build is always available at http://mielke.cc/brltty/brltty-latest.apk (about 1.2 MB). Accordingly, before installing, you must not forget to activate the checkbox allowing the installation of programs from unknown sources, which is located along the path “Settings \ Security \ Unknown sources”.
Natively BRLTTY supports Android starting from 4.1 (Jelly Bean), but it can be installed on 4.0 (Ice Cream Sandwich), but many useful functions will not work.
After installation, BRLTTY appears in the general list of Android accessibility services, which is located under the path “Settings \ Accessibility”. Switching on is carried out in the standard way through the switch in the main window, which opens immediately after activating the item “BRLTTY”. It also contains the “Settings” item, which provides access to the service settings menu.
The BRLTTY interface has Russian localization, and the program itself contains translation tables for displaying Russian braille text, so Russian-speaking users should not experience any language problems.
Braille displays can be connected for use with the BRLTTY via both Bluetooth and USB. Serial port is not supported as such, but such a device can be connected via USB using an appropriate adapter. However, when using a USB connection, remember that the Android device connector must provide the appropriate voltage level to power the display, otherwise power from an external source will be required. Unfortunately, not all modern Android devices are capable of supplying power to USB-connected peripherals, so this aspect should be foreseen.
When using a Bluetooth connection, you must first pair the display in the Settings \ Bluetooth menu, but when connecting via USB, it makes sense to stock up on a Micro USB host adapter.
After connecting the display to an Android device, you need to select it in the BRLTTY settings. To do this, go to the “Settings \ Accessibility \ BRLTTY \ Settings \ Device Management” path.
This menu contains a drop-down list for selecting one of the previously added devices, as well as items for removing and adding a new device. When performing the operation of adding a new device, you must first select the connection method, then the device itself and then one of the braille drivers. After that, you should go back one level and select the newly added device from the drop-down list.
It is important to note that when working with BRLTTY, input from the braille keyboard is supported, but traditionally for Android must be manually activated due to system security requirements. To do this, in the “Settings \ Language and Input” menu, select the “BRLTTY Input Service” checkbox, then grant all the necessary permissions, and then select the BRLTTY keyboard as the default keyboard.