You cannot find a Braille decoder sheet in any of the Pokemon games. Braille is very simply and easy to translate if you print off a Braille alphabet sheet for reference.
A braille decoder sheet is typically found in educational resources for visually impaired individuals, often available in schools, libraries, or organizations that support the blind and visually impaired. You can also find printable versions online through various educational websites and resources dedicated to braille literacy. If you're looking for a specific decoder sheet, checking with local organizations or braille transcription services may be helpful.
In Pokémon FireRed, you can find the Braille decoder in the Pokémon Center in Saffron City. After obtaining the Ruby and Sapphire from Team Rocket's hideout, you can return to the center and talk to the woman in the back room. She will give you the Braille decoder, which helps you interpret Braille messages found in the game, particularly in the cave areas.
There is no "braille decoder", you have to manually decode it yourself.
Sadly, the game itself provides no translation sheet. However, if you take a look at one of the game's many game guides (either in print or online) there should be a decoder sheet on any source worth its salt.
Using a braille decoder.
Go to wikipedia, they have a braille dictionary.
Those symbols are braille letters. To decode them, just search "braille decoder" in google. They give you instructions on what to do to get into the next room. In the next room is one of the regis. (Regice, Regirock, Registeel)
braille is a way for blind people to read. you need to get the decoder to read it.
A person can read the braille in the Secret Chambers in Pokemon Sapphire by translating the braille to the corresponding letters of the alphabet. A person will be required to dig to reach the appropriate area of the chamber.
You can obtain a braille decoder from various sources, including online retailers like Amazon or specialized accessibility websites. Additionally, organizations that support the visually impaired often provide resources or tools, including braille decoders. Some educational institutions or libraries may also have these tools available for public use.
You can research "How to read Braille" for more information.