Mapping Indic scripts is difficult as Braille has a unified script
Braille, with its raised and flat dots, is somewhat similar to the binary world of computers. A Braille letter is composed of a cell which has a maximum of six raised or flat dots. This means that you can map up to 64 characters in Braille, including the space.
For English, after accounting for 26 letters, 10 numbers and the space, you have 23 permutations left to accommodate punctuation, and diacritics.
Printing Braille texts
It is quite difficult to print Braille texts manually because of the time taken to print each character. In the beginning, Braille texts were printed using a slate and a stylus. In 1951, the Perkins Brailler, a Braille typewriter with seven keys, was invented by David Abraham. It has since evolved to include features such as audio feedback for the typist. Braille embossers, the equivalent of electronic printers, have also simplified the process producing Braille texts. While the more expensive ones can print up to 2,000 pages an hour, the humbler versions may print around 200 pages a minute. The embossing process involves pressing pins onto one side of a sheet of paper. Some of these printers can also accept typed input from a QWERTY keyboard, which, when used with suitable Braille simulators, can type in Braille. Several of these Braille simulators can be found on the Internet through a simple search.
In India, Bharati Braille has mapped Indic scripts to Braille letters. It has a unified script, which means that consonants with the same sound are mapped to the same Braille character, irrespective of the language they come from. For example, Ka in Devanagari and Tamil are mapped to the same Braille character. This means that you cannot have a bilingual text without explicitly specifying the change in language every time. Most Indic languages have more than 60 characters because of the large number of vowels, consonants and characters arising from the combinations of vowels and consonants. If we include Indic numerals, the number of characters may be more than the available number of Braille characters. This makes it difficult to map each of these characters to a unique Braille grid. Thus, the same Braille character may be used to print a letter, a number and punctuation, with the number and the punctuation having special prefixes to differentiate them from letters.
While online Braille transliterators are aplenty for English, the same is not true for Indic scripts because of the lack of sensitive research in this direction. One such transliterator to map letters in Devanagari to Braille has been started by the team of Pooja Saxena and Nirbheek Chauhan. The project was started by the duo when they realised, according to Ms. Saxena’s blog, that the only Indic transliterators on the Internet were “proprietary and prohibitively expensive”. The transliterator, a FOSS project, can currently convert Devanagari texts to Braille while efforts are on to transliterate texts from other Indic languages to Braille. You can contribute to this project by visiting bharati-braille.