Braille keyboard

Braille can not only display, but also to enter information. In the classic 6-bit version of this font, the sign consists of two columns of three bits each. In the braille keyboard, both columns are expanded in one line, three bits for each hand. The proposed homemade keyboard of this type sounds the input characters and simultaneously sends them to the serial monitor, from where the text can then be copied to another application for subsequent editing.

Forgive me all consider it a move, but the author performed the scheme in something Fritzing'like. In addition, he forgot to add capacitors to 7805 to prevent self-excitation - they must be supplied. But the way the image of the scheme did not affect the performance of the design, copes with its functions.
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The codes of numbers in Braille are similar to the codes of the letters A - J, each number must be preceded by a special sign "Now the numbers will go":



But in order for the keyboard to sound and transmit numbers to the serial monitor instead of letters, it must be switched to the appropriate mode by a switch connected to one of the Arduino inputs in the same way as the buttons. Both the buttons and the switch are equipped with pull-up resistors (1 kΩ).

Files for voicing characters are stored on a memory card, it is necessary to format it in FAT32:



In Linux, it is .

Then put on it the files downloaded from here . And in Arduino fill the sketch , after changing the file extension from TXT to INO.

To receive typed characters, you can use either the Arduino IDE serial monitor or any terminal emulator. The author prefers CoolTerm for the ability to immediately write the entered characters in a text file, but not only this program can. Parameters: 9600 Baud, 8 bits, no parity, one stop bit, DTR and RTS included. When everything works, you can try to type some text:



Brief video tutorial and keyboard test:


To be able to immediately type on any keyboard text in any program, the firmware needs to be improved by adding the function of the HID device. But not all Arduino-compatible cards support this mode.