Hardware issues gone for +bus


Solve digital signage hardware issues in public transportation like a boss, like +bus

Implementing digital signage implies choosing devices that best suit your business’ needs. It wasn’t different for the signage operator +bus who had to come up with solutions for Uruguay’s capital fleet challenges

Providing community engagement and a joyful environment among the commuting people of the capital of Uruguay: that’s the goal +bus has successfully achieved. Nonetheless, it took a lot of effort and planning in the last two years for the company to reach its current number of 100 managed screens spread over 10 bus lines of Montevideo.

Recently, we did an interview with the chief technology officer (CTO) of +bus, Edgar Blumenfeld, where he mentioned they have had their share of opportunities that came from failure. Overcoming difficulties is what makes +bus better every day.

Have a glimpse of +bus, why and how they have been using OnSign":

The company set forth to provide a service that usually needs certain requirements in a place that lacks them, namely buses. In any other segment, you have access to constant internet connection, a stable vibration-free surface to fix your player to and steady energy supply. Yet, on public transportation, all of these characteristics fall short.

These guys took a well-thought and resourceful approach of thoroughly screening for economic and effective options in the market and making them work for them, sometimes iterating more than once. +bus is clearly up for the challenge.


There isn’t a hardware in the market that is specifically developed for public transportation. Currently, 24/7 usage industrial grade hardware systems have a high cost, hence, are only affordable for certain businesses and in large economies. As it’s not reasonable, from a business perspective, to pay about U$ 1,000 and more per screen, +bus chose the products developed for home use and modified them to withstand permanent use and being on a moving bus.

For their operating system they chose Android at a time when digital signage neglected it completely. As it turns out, Android ended up being the best choice for digital signage.

Energy supply

The energy generated by buses is not like the one we have in our homes. Instead of the common 110 or 220V, buses operate on erratic 24V. Therefore, smart power transformers that take a wide range of input from 9 to 48V have to be used to control electrical surges that could burn the equipment as a result.

These surges are especially critical when power skips flowing for short instances altogether. Units turn off and if it happens too often, they won’t boot anymore - just like any normal computer when the plug is pulled abruptly. The file system is also affected as some data can be erased unintentionally. This problem could be detected by carefully analyzing logs with OnSign TV, the software provider. By rewiring the system, thus improving the shutdown process, +bus went from 23% problems every day to 1% or less after 6 weeks. Today the out-of-order rate for players is at astonishing 0.2%.

Internet connection

Different from a shopping mall, where a broadband fiber optic cable can be used, buses rely on mobile network as they drive through areas with better or worse signal strength. In order to function well, they require good hardware, like modern modems and routers, as well as a good software. Having a good connection is not only necessary for sending new content, but also to monitor the players. That’s why +bus opted for mixing commercial modems and routers with a custom made Linux Software that controls the connection.

In the beginning, they’ve noticed that about 60% of their screens were not connected to the internet at all moments. That’s because the router would lose connection and fail to reconnect. The solution was rebooting the computer as soon as the problem was detected, using a custom firmware for the router. After introducing this device, the number of screens with connection failures dropped to 15%.

Bus vibration

As the bus rides on bumpy roads, the screens have to cope with damaging vibration. In many areas the buses passed through the vibrations hit 4, 5 or even 6 G. That’s 6 times their own weight. That kind of energy and vibration can break things apart.

In +bus’ case, they’ve noticed some white dots appeared on the screen. In order to safeguard their signature quality HD image, +bus created a dampening system - similar to the one used in cars - closing the whole screen assembly inside the chassis so the vibrations the computers and screens had to absorb were minimalized. This measure had a huge positive impact on their investment and maintenance of the mainly 23’’ screens.

All these problems were part of +bus development process, which included a lot of error analysis, solutions for development and implementation. Alongside with tailored content to the commuters and a solid commercial strategy, +bus has been successfully established in bus lines where about 750 thousand people cross every day.

Connect directly to +bus or Edgar Blumenfeld on Linkedin and view +bus on Youtube.