According to the World Health Organization, 2.2 billion people have some vision impairment globally (WHO 2021). The impairment prevalence in low and middle-income areas, like Mexico and Latin America, is estimated to be 400% higher than in high-income regions. In addition, the blind and vision impairment population faces severe social and academic exclusion. For instance, children can undergo poor motor, language, and cognitive evolution, bringing lower levels of educational success.
Braille script represents a language's characters in a rectangular arrangement of raised dots so that blind people can read the symbols and obtain written knowledge through the touch sense. Braille characters are generally printed in books or on commonly used surfaces such as ATMs. However, printing requires many resources since it must be done for each occasion. This is why electronic braille displays were created that connect to a computer or smartphone and tactilely represent the text shown on the screen. Unfortunately for people in developing countries, it is not easy to access this technology since its cost is very high.
Hence, this paper shows the design and development of a one-character refreshable braille display that is affordable and easy to use through the Internet of Things (IoT) technology. The MQTT protocol was used to communicate the digital text and convert it into physical braille text; the MQTT is a well-known messaging protocol for the IoT. The device was designed with electromagnetic push-pull solenoids connected to an ESP-32 microcontroller card. Each solenoid represents a dot of the braille character through its vertical movement, which allows blind people to read from the device by touch. Reading is essential to acquire knowledge by allowing an affordable form of reading based on braille, a handy tool for teaching and training blind and visually impaired people can be reached.