An embedded web-server and web-based user interface on a BeagleBone Black for audiometric test equipments


Nilson Nascimento da Silva

11.11.2014, 13:00, room 3999


There are many different objective methods of hearing capacity evaluation such as Otoacoustic Emissions, which relies on the response caused by tones with specific frequencies and levels being emitted, or Auditory Brainstem Response that measures electrical activities generated through stimulation of the auditory nerve by transient sound such as a click and registered via skin electrodes, biopotential amplifiers and computer averaging.

In this interdisciplinary project a web-based GUI for controlling an audiometric platform that offers the aforementioned methods based on an open source development board (BeagleBone Black) with Linux operating system was implemented and evaluated.  All user interaction should be controlled using standard tools such as any common web browser while also supporting other system features as multi-user management and multi-device (e.g., PCs, tablets, smartphones) capabilities.  Two different web server architectures have been implemented on the BeagleBone Black.

The first approach is based on a "full web stack" including Nginx HTTP server, Tornado Websockets server and Web2Py application framework.  The second design is based on a simple and lightweight C-library, Libwebsockets, which handles all server related tasks including HTTP static file delivery and Websockets packets transmission.  Both designs have been benchmarked in terms of efficiency and performance.

Finally a skeleton code base was developed to facilitate the expansion and evolution of audiometric test applications.