Nowadays most embedded designs on the market, from consumer white goods to industrial machinery, incorporate some form of display. The current sophistication of touch displays, enabling commands to be given through swipes and gestures, owes much to the early smartphone designers. Touch-enabled LCD displays can reduce system cost by removing the need for switches and push buttons. Product reliability can also be improved by using capacitive touch screens to avoid dust and moisture ingress through switch enclosures. Additionally, a well-presented, visually pleasing and intuitive display contributes significantly to the aesthetics of a product, strengthening product brand value and user confidence.

Designers must make a choice when building a display into their embedded systems – design from scratch or use an off-the-shelf module. Whilst both have their merits, and the specifics of some designs may dictate the former approach, display design has become a speciality and there is a comprehensive range of off-the-shelf devices on the market.

We discuss 5 factors to consider when choosing between discrete design or off-the-shelf modules and look at a specific module, the gen4-uLCD-43DCT-CLB from 4D Systems.

The impact on the MCU resources

The choice of MCU is driven primarily by the computing and interfacing needs of the embedded application, and integration of a display into the design can increase the required MCU specification. Additional memory must be allocated for the display frame buffer and the MCU must compose the image to be displayed in the buffer, incorporating images and icons in addition to processing the data to be displayed. Some displays incorporate a video controller which reads the data in the display buffer and writes it to the display itself, whereas others don’t, leading to additional overhead on the MCU. In summary, the MCU must be capable of running the display and frame buffer tasks in addition to managing the core application

On the other hand, separate display controllers have most of the above resources integrated on chip, including frame buffer memory and microcontrollers. They also feature industry standard interfaces, enabling easy interface to the host MCU which can therefore offload the display tasks and dedicate all its resources to the application.

Using a module such as the 4.3-inch gen4-uLCD-43DCT-CLB from 4D Systems (figure 1) in a design can enable a lower specification – and hence lower cost – to be used.

Figure 1: gen4-uLCD-43DCT-CLB from 4D Systems

The length and complexity of the design cycle

Designing discrete display systems very often ends up being more complicated and costly than initially expected, with many unforeseen challenges. Drivers must be written for the display controller, and also primitives have to be developed to allow icons, fonts and stored images to be written to the display. The primitives also need to include basic graphic functions such as drawing lines, circles and boxes, after which a GUI for the application must be implemented. The display hardware needs to be laid out around the main application and everything debugged and tested and a design cycle of between 4 and 6 months isn’t unreasonable.

Display modules, such as the gen4-uLCD-43DCT-CLB, usually come with all of the drivers, primitives and GUI functions already developed and tested. The off-the-shelf approach can therefore significantly reduce the overall design time of the embedded system.

A quality display module will be supported by development tools

Many families of display modules, such as those produced by 4D Systems, are supported by integrated software development environments, (IDE). 4D’s Workshop4 IDE, (figure 2), provides three main ways to support the development of display application code. Professional developers can use the IDE, writing their own code in the 4DGL graphical programming language. The ViSi method enables a drag-and-drop approach together with the ability to add application-specific 4DGL code, whereas the third method – ViSi Genie – offers a completely codeless approach to designing a graphic application interface.

Furthermore, a 4DGL library is provided to simplify communication between the host MCU and the display module, reducing the amount of data needing to be transferred between the two.

Figure2: Workshop 4 IDE from 4D Systems

Product time to market

As discussed above, use of an off-the-shelf module can significantly reduce time-to-market by reducing the 4 to 6-month design cycle often required for discrete implementations. In today’s fast-paced consumer environment, this reduction in time to market may be the difference between product success or failure.

Total product cost

A straightforward consideration of the bill-of-materials for a planned embedded system may lead to the conclusion that a discrete design is more cost effective. However, careful consideration of the total costs of production may well give a different perspective. Designing with an off-the shelf module can enable use of a cheaper, lower-spec MCU as the display-related tasks can be off-loaded. Design and production costs can be significantly reduced, both by avoiding the need to develop dedicated hardware and software to manage the display, and also by taking advantage of the support offered by an IDE.

Finally, reduced time to market means earlier access to revenue and the increased market share that comes with early market entry.

When faced with adding a graphical LCD display to a design, engineers should carefully consider whether a discrete approach can be accommodated within the project timescales and cost budget. Intelligent display modules, together with their graphical design tools, can significantly reduce the length of the design process, enabling working prototypes to be delivered in shorter timeframes.

Adopting a total-cost approach, including the savings from the reduced design time as well as the benefits of faster time to market may fundamentally favour use of off-the-shelf modules over discrete design.

Creativity is fundamental to being human; it sets our species apart from most others and yet it isn’t easily assigned to any specific area of the brain. There is something about how the human brain functions that allow creative and abstract thought. It is so fundamental that, without this ability, we may not have evolved beyond simple bipeds.

Given that creativity is an innate ability within all people, it isn’t surprising that with the right tools we can make wondrous things. Access to those tools improves with every generation, a compound effect that results in exponential leaps.

Consider YouTube, for example. It is a community of Makers whose chosen medium is video. How many YouTubers went to university to study media? How many have spent years working in the broadcast industry? And how many have completed hours of drama schooling? The answer is probably very few, on all accounts, yet the results of their labours are clearly good enough to in one way or another to attract millions of views.

Human ingenuity has created the technology that enables both the platform and the content, but it is human creativity that provides that little something extra. Nobody really knows how creativity works at a cellular level, researchers have tried and failed to detect the part of the brain most likely responsible for creativity, but it is clearly a tangible quality we all possess. The Makers of this world successfully mix creativity with the knowledge to produce something that simply didn’t exist before, and every time it happens it is just as amazing as the first.

The rise of open source hardware and software has helped accelerate this process, while online communities supporting the Maker movement have added the commercial synergy needed. This gives Makers access to the technology they use to realise their vision and goes far beyond what we may normally call an ecosystem. It has reached a level of activity that rivals many fully commercial enterprises and is beginning to be recognised as something more significant than hobbyists working in their shed at the weekend.

The next big thing is in you!

There is every expectation that the next big scientific breakthrough could come from a Maker, but just as creativity remains an elusive but tangible property, Makers are also difficult to define. Does it exclude anyone with a professional interest in science and technology? Should it be restricted to those who have had no formal training in either, or can we apply it as liberally as, say, an artist? Art is subjective and has very few boundaries, those that do exist will be challenged as soon as they are recognised, the same could be said about Makers. Tell someone it can’t be done and they will try twice as hard to prove you wrong, and often those who succeed are the ones that don’t know they are likely to fail.

Perhaps that is the discernible difference between a Maker and a professional engineer; the former learns through failure while the latter is afraid to fail. This is extremely liberating for engineers who would like nothing more than to try, try and try again.

We have arguably reached a stage now where Makers are really R&D engineers working in a new field, without the commercial pressures of deadline, budgets and customers. Of course, many Maker projects now successfully transition to commercial products thanks in part to online crowdsourcing platforms, which typically charge a commission on funds raised but provide a valuable route to market for Makers. Companies that practice ‘intrepreneurship’, allowing employees to pursue Maker-style ideas that may become viable products for the company, stand to benefit greatly from the freedom that extends to their in-house talent.

The Maker movement is now so important to commercial companies that they are willing to put significant resources into enabling it. This includes 4D Systems, which now has a site dedicated to Makers (www.4dmakers.net) where people can meet, create, share and discuss their ideas, and make them a reality.

The secret source

It is unlikely that the Maker movement in electronics would thrive if it wasn’t for open source hardware and software. With community-led projects such as Raspberry Pi and Arduino, industry-led platforms like BeagleBoard, and software communities such as Linux, the building blocks are all there. As the level of abstraction from the ‘nuts and bolts’ of technology increases, it not only opens them up to more Makers with fewer skills, but it gives those that do have the skills a solid platform from which to start. This is where they add their own secret source that makes an off-the-shelf board into a bespoke solution.

It is becoming more relevant and more important to consider what happens next; open source platforms provide a trampoline for ideas but they can also be used for mainstream production volumes, at least up to a point. More commercial companies are willing to engage with Makers in low-volume projects at an early stage, providing valuable support and expertise in order to help individuals achieve their goals. This can be seen as ‘paying it forward’ by some or simply as good community spirit by others.

One thing is certain, it’s never been easier to take a ‘back of an envelope’ idea and turn it into something real.