Designing hardware for success in the digital signage market

November 01, 2012

As the economies of digital signage grow, embedded designers are tasked with making the costs shrink. To maintain ROI, developers of digital signage s...


The growth of digital signage is being driven by the fact that product sales increase when local advertisements are displayed. Various reports show sales increases from 8 percent to 50 percent due to digital signage use. Furthermore, users have developed a need for more information and entertainment and have become more accustomed to digital signage. Meanwhile, the cost of digital signage has reduced, thus increasing the opportunity for vendors to achieve substantial ROI on capital expenditures for screens, software, players, and content management.

Improvements in broadband communications have also contributed to this growth, allowing content to be streamed to digital signage systems rather than circulated by flash disks or DVDs. Real-time changes to content and scheduling are now common and, along with other technology advancements, are expanding the market for digital signage.

In many ways, the digital signage market is now quite mature, so the players must work harder to find new business. As a result, the market is moving toward low-power, small-footprint, lower-cost hardware/software products. This trend is helping the industry maintain existing clients and penetrate new areas to maintain sales revenue.

ARM-based low-power technology

The digital signage industry comprises several major software suppliers including Scala and Omnivex. These companies develop high-level application software that enables the screen to be configured, messages to be scheduled, and general system performance to be controlled.

This application software runs on an embedded hardware platform. The most common form of hardware is an embedded PC running Windows XP Embedded from a hard drive. This choice is primarily driven by the low cost and scalability of Windows XP Embedded.

To meet the demand for small, low-power hardware for lower-end digital signage applications, designers are using ARM-based smart phone technology as the basis of the hardware platform. Offering power consumption of 1 W to 2 W, no moving parts, ultra-compact size, high-temperature operation, and rich functionality, the latest ARM-based devices with 720p/1080p graphics engines and support for Windows CE/Embedded Compact, Android, or Linux enable the creation of small, rugged, low-cost platforms that are ideal for this next stage of the industry. This new technology is helping digital signage companies target small retail organizations, hotels, and sporting venues, as well as offering shelf-side digital signage products in retail outlets.

Design requirements

One of the major challenges of developing hardware for digital signage is ensuring true 24/7 reliability. The cost of sending an engineer to the site to investigate and repair a system can be expensive and, if numerous trips are necessary, can easily ruin a business model. To curtail these expenses, digital signage hardware must be designed to work continuously without technical problems in difficult environments.

For projects with a large rollout, custom-ers require hardware with a long life cycle. They want to deliver the exact same hardware to ensure that the costs of management and ownership are as low as possible. Any variation of the deployed hardware will add cost to the creation and maintenance of software images, spares, and so on. Hardware design should therefore be sensitive to the life cycle of all components in the digital signage player. In contrast, with small projects, customers are more likely to request the latest technology, regardless of the long-term ramifications.

A final design consideration is the electrical environment in which digital signage is often used. One example of a potentially harsh environment is a railway station, where noisy mains and temporary power outages can occur. These risks affect the design of the power supply (holdup time, backup, and filtering), as well as the bootloader or BIOS, given that specific software might be essential to enable reliable power-up and graceful shutdown/reboot to protect the quality of service and meet availability criteria.

Leveraging technology advancements

Addressing these design challenges, the latest-generation ARM-based fanless SBCs enable a fit-and-forget approach to digital signage players, which is vital in these cash-starved times as costs for installation, support, and maintenance are being squeezed.

For example, the Blue Chip RE2 digital signage platform (Figure 1) uses the ARM Cortex-A8 processor and a Texas Instruments C64x DSP to handle high-quality graphics such as moving media or 3D while managing complex tasks. Various peripherals and connectivity options are supported, including LCD (RGB/LVDS), DVI/HDMI, RS-232, RS-422/485, audio, SD, GPIO, real-time clock plus battery, touch-screen controller, 7 V to 36 V DC power input, Wi-Fi, and Bluetooth. The platform is built to industrial computer standards and has an extended temperature range of -40 °C to +85 °C at 600 MHz to ensure reliability.


Figure 1: The Blue Chip RE2 ARM-based SBC offers graphics capability to drive 720p resolution video content in digital signage applications such as the public phone-charging kiosks pictured at the beginning of this article.




Utilizing dual- and quad-core ARM Cortex-A9 and Freescale i.MX6 technology, the RE3 platform will soon be available, offering additional features such as SATA, video capture, Mini PCI Express, SIM socket for 2G and 3G/4G, and four USB 2.0 host ports. The RE3 can also drive two independent displays simultaneously. While resolutions depend on one or two displays being driven, 1080p plus another high-resolution screen is achievable.

Improved networking and bus technologies are also enabling intelligent distributed systems, remote configuration, and video streaming. Although Wi-Fi has been welcomed by many industries, the digital signage sector has some concerns about data security, so it is not currently featured in digital signage systems.

Choosing whether or not to use sound in a digital signage installation can be a tricky decision. While the added impact of sound cannot be ignored, there is a fine line between an attractor and a repellent. If sound is perceived to be too loud, it can be irritating to the target audience. If it is too quiet, then it can be ineffective. Various mechanisms have been employed to sample the ambient noise and then select the “correct” volume level. When sound is required in news or entertainment broadcasts, most hardware platforms provide a line-level output using an audio chip for feeding into an external audio system.

Cost of ownership

In the past, success in the marketplace used to come down to the screen, then software, then the player’s graphics ability, and after that, cost of purchase. Today, success tends to be driven by cost of ownership, power consumption, and software capabilities.

As this hardware can be running 24 hours a day, often as a multidistributed system, energy usage has become an important factor for the decision maker. The market is now embracing extremely low-power devices. Cost of ownership (maintenance contracts and license costs) has become a similar issue, whereby end users are now desiring license-free products they can own and manage themselves. In this respect, control software is moving toward more simple and intuitive interfaces.

Exceeding design expectations

The success of a digital signage system boils down to the ROI that the customer gains from the project. The system has to work, offer impressive features, and be reliable. All in all, it can be a tough market to keep up with.

However, with many advancements made in embedded systems technology during the past few years, engineers have been able to meet and even exceed the expectations of the digital signage marketplace. As a consequence, it remains an important sector for SBC manufacturers and silicon suppliers.

Barry Husbands is the managing director of Blue Chip Technology.

Blue Chip Technology [email protected]