USB Braille Machine

Project Summary

The objective of this project is to simulate the FPGA (Tang Primer 20K) as a HID keyboard via USB Full Speed protocol. Instead of a normal keyboard, the project takes advantage of the peripherals of the ChipInventor Devboard 2.1, such as buttons, switches and seven segments display, to simulate a Digital Braille Machine.

 

Implementation

This digital Braille Machine is projected using the ChipInventor platform and implemented on the Tang Primer 20K FPGA. The project utilizes 8 buttons and 2 switches of the Devboard to convert Braille combinations into standard keyboard outputs using USB HID (Human Interface Device) functionality, allowing seamless integration with computers without additional drivers.

The following table outlines the key specifications of the project and its hardware requirements:

 

Table 1 – System Specifications

Field

Description

FPGA Board

Tang Primer 20K

FPGA Core

Gowin GW2AR-18

USB Functionality

HID (Human Interface Device) – Recognized as a keyboard

Input Interface

6 Braille buttons + function keys (Caps Lock, SpaceBar button, Delete, Number Mode)

Braille Standard

International Braille (Unified Standard)

Supported Characters

Uppercase and lowercase letters, numbers

Unsupported Characters

Special symbols and punctuation marks

Clock Frequency

27 MHz

Button reading interval

1 second

Power Supply

5V via USB-A

Programming Interface

JTAG or USB Programmer

The project is based in Internationally Standardised Braille.

Here is the blocks diagram of this project:

Visual Resources

Figure 1 – Internationally Standardise Braille dots arrangement


Figure 2 – Internationally Standardise Braille alphabet and numbers



Figure 3 – Input keys placement

 

Figure 4 – How to connect