BrailleDisplay Arduino Library

Overview

BrailleDisplay is an Arduino library designed to interface with P20 Metec refreshable braille displays. It allows users to send Braille characters to the display, manage scrolling text, and control individual Braille cells with ease.

Features

• Supports writing single Braille characters to individual cells.
• Displays multiple Braille characters at once.
• Scrolls text when the input exceeds the available cells.
• Allows direct manipulation of Braille dot states.
• Adjustable wait and delay times for smooth operation.
• Compatible with P20 Metec refreshable braille displays.

Installation

1. Download the repository as a ZIP file or clone it:

   git clone https://github.com/yourusername/BrailleDisplay.git

2. Copy the BrailleDisplay folder into your Arduino libraries directory.
3. Restart the Arduino IDE.
4. Include the library in your sketch:

   #include <BrailleDisplay.h>

Usage

Initialization

#include <BrailleDisplay.h>

#define CELL_COUNT <Number Of Cells>
#define ON_PIN <On Pin>
#define DIN_PIN <Data In Pin>
#define LATCH_PIN <STROBE Pin>
#define CLK_PIN <Clock Pin>
#define DOUT_PIN <Data Out Pin>

BrailleDisplay display(CELL_COUNT, ON_PIN, DIN_PIN, LATCH_PIN, CLK_PIN, DOUT_PIN);

void setup()
{
    BrailleDisplay.begin();
}

Writing a Character

void setup()
{
    BrailleDisplay.writeCell('A', 0); // Writes 'A' to the first cell
    delay(1000);
    BrailleDisplay.clear(); // Clears the display
}

Writing Full Text

#define PATTERN_LENGTH 7

uint16_t pattern[PATTERN_LENGTH] = 
{
    0x283a,  0x2811,  0x2807,  0x2809,  0x2815,  0x280d,  0x2811
  // 0x283a,  0x2811,  0x2807,  0x2809,  0x2815,  0x280d,  0x2811
  //    ⠺         ⠑        ⠇        ⠉       ⠕        ⠍        ⠑ 
  //    W         E        L        C        O        M        E   
};

void setup()
{
  BrailleDisplay.begin();
  BrailleDisplay.writeCells(pattern, PATTERN_LENGTH, false);  // the final boolean argument in the function enables to display the text in reverse order is initialized to true 
}
  

Controlling Individual Dots

void setup()
{
  BrailleDisplay.setDotState(0, 0, 0); // sets the first dot of the first cell (from left) to HIGH
  BrailleDisplay.setDotState(3, 2, 1); // sets the fourth dot of the third cell (from left) to LOW
}

Adjusting Wait and Delay Times

• Wait time: Interval between updating two consecutive cells.
• Delay time: Interval between scroll updates when text exceeds available cells.

void setup()
{
    BrailleDisplay.setWaitTime(3000);  // Set wait time between cells
    BrailleDisplay.setDelayTime(500); // Set delay time for scrolling
}

API Reference

Function	Description
begin()	Initializes the display.
writeCell(char c, uint8_t cellIndex)	Displays a character in the specified cell.
binaryWriteCell(uint8_t cellIndex, byte BYTE)	Takes 1 byte of binary input and writes it to the cell at cellIndex.
writeCells(uint16_t* pattern, uint8_t length, bool reverse)	Displays text on the display. If the length of text is greater than number of cells, then the text is scrolled across display.
setDotState(uint8_t cellIndex, uint8_t dotIndex, uint8_t state, uint8_t* dotMap)	Sets the state of an individual dot.
setWaitTime(uint8_t waitTime)	Sets the wait time between two consecutive cells.
getWaitTime()	Returns the current wait time.
setDelayTime(uint8_t delayTime)	Sets the delay time between scroll updates.
getDelayTime()	Returns the current delay time.
clear()	Clears the display.

Hardware Compatibility

This library was developed with P20 Metec braille displays in mind. Compatibility with other hardware may require adjustments.

Contributing

Feel free to contribute by submitting issues and pull requests!

Authors

Developed at Sejong University by Prithwis Das under the guidance of Prof. Luis Arturo Cavazos Quero.

License

This project is licensed under the MIT License.

Copyright

© Prithwis Das 2025. All rights reserved.