Unicode braille patterns

Unicode characters exist to represent all 256 braille characters possible in an eight-dot braille cell. These Unicode characters are in the hexadecimal range from 2800 to 28FF (decimal range from 10240 to 10495).

Determining the Unicode value for a braille pattern

We can calculate the Unicode value for any patten of dots:

1. Start with 2800 (hexadecimal) or 10240 (decimal).
2. If a dot is present in dot position 1, add 1 (that is, 2 raised to the power 0).
3. If a dot is present in dot position 2, add 2 (that is, 2 raised to the power 1).
4. If a dot is present in dot position 3, add 4 (that is, 2 raised to the power 2).
5. If a dot is present in dot position 4, add 8 (that is, 2 raised to the power 3).
6. If a dot is present in dot position 5, add 16 (that is, 2 raised to the power 4).
7. If a dot is present in dot position 6, add 32 (that is, 2 raised to the power 5).
8. If a dot is present in dot position 7, add 64 (that is, 2 raised to the power 6).
9. If a dot is present in dot position 8, add 128 (that is, 2 raised to the power 7).

Determining the dots present from a Unicode value

We can determine the dots present from a Unicode value in the hexadecimal range from 2800 to 28FF or the decimal range from 10240 to 10495:

1. Subtract 2800 (hexadecimal) or 10240 (decimal) from the Unicode value to give a value in the hexadecimal range from 0 to FF or the decimal range from 0 to 255.
2. If the value is greater than or equal to 128 (that is, 2 raised to the power 7), subtract 128 and include a dot in dot position 8.
3. If the value is greater than or equal to 64 (that is, 2 raised to the power 6), subtract 64 and include a dot in dot position 7.
4. If the value is greater than or equal to 32 (that is, 2 raised to the power 5), subtract 32 and include a dot in dot position 6.
5. If the value is greater than or equal to 16 (that is, 2 raised to the power 4), subtract 16 and include a dot in dot position 5.
6. If the value is greater than or equal to 8 (that is, 2 raised to the power 3), subtract 8 and include a dot in dot position 4.
7. If the value is greater than or equal to 4 (that is, 2 raised to the power 2), subtract 4 and include a dot in dot position 3.
8. If the value is greater than or equal to 2 (that is, 2 raised to the power 1), subtract 2 and include a dot in dot position 2.
9. If the value is equal to 1 (that is, 2 raised to the power 0), subtract 1 and include a dot in dot position 1.
10. If the value is anything other than 0, something has gone wrong.