BeagleBone Black project spotlight blog post: Kuyurix Bus Speakers

Commuting in a big city is a tough task, especially when public transit and traffic
congestion make the process even more difficult. For someone who is blind, finding
your way around the city on public transportation in these conditions can seem daunting,
or nearly impossible. Marcelo Gutierrez recognized this issue and wanted to do something
about it.

Marcelo is a university professor teaching digital signal processing and Linux-embedded
courses. He designed and developed the Kuyurix, an audio-based system to assist people
who are blind on public bus transportation. It notifies passengers of upcoming main
streets and approaching points of interests, such as a hospital, making public transportation
much more comfortable for those with any visual impairment.


The voice announcement system provides passenger information by an FM transmitter
connected to two speakers that carry the message. Marcelo used the free samples service
from Texas Instruments when constructing the first prototype. He integrated TI’s
TLV320AIC3106 audio codec, TPS73701 linear regulator, LM4871 audio power amplifier
and LM22676 switching regulator.

“At the university from which I graduated, there is a library service for blind and
partially sighted people,” said Marcelo, an electronic engineering alumnus from Universidad
Tecnológica Nacional – Facultad Regional Haedo. “So I thought [Kuyurix] might help
to make their lives just a little bit easier.”

BeagleBone Black was chosen to power the bus speakers. All signals are present on
expansion headers, making cape development easy, and it incorporates an ARM® Cortex®-A8 core
(within TI’s Sitara AM335x processor) that runs with low power consumption. In comparison
to similar products, BeagleBone Black provided the best performance for Marcelo’s

“Two weeks on the bus and BeagleBone Black is solid as a rock,” Marcelo says.

Marcelo faced some challenges during the creation of the Kuyurix bus speakers. The
main challenge of this project was choosing the proper GPS module. The first GPS receiver
integrated a built-in patch antenna, but it didn’t have the reliability that Marcelo
expected. He then tried another module that uses an active antenna, which significantly
improved the performance of the device.

Marcelo is now working on developing a digital TV receiver box. He is doing this by
connecting a USB ISBD-T TV stick on a BeagleBone Black. The product will be introduced
on public bus transportation in just a few weeks.

If you’d like to learn more about the Kuyurix bus speakers, feel free to contact Marcelo
via Twitter (@efectomiller).

Marcelo would like to give special thanks to the Department of Electronic Engineering
(UTN/FRH), Ing. Carlos González, and the professor Ing. Fidel Santos, for their assistance
and generosity in helping implement the Kuyurix speakers.

Want to chat with us about this project? Tweet us at @BeagleBoardOrg!