The current generation of consumers expects all of its electronics — from portable music players to alarm clocks to clothes washers — to provide much more than just basic functionality. Products like the iPod have driven all markets to satisfy a new demand for cool, up-to-the-minute touch screen displays. The same old knobs or switches on a new product will not win over today’s electronics buyers. To differentiate new products and keep up with competitors, companies must offer exciting, full-color touch screens that are both easy and fun to use.

Developers in the home appliance industry face two incredible challenges as the result of this new trend in interactive displays. First, time is of the essence. They need to get their new products to market now. But the development of a new interface takes time, money and experience that developers in this industry have never needed before. With the current state of industry and the economy, companies are cutting back; they’re not expanding their workforce to outsource or hire a team of pricey, experienced GUI programmers.

Squeezing this extra, potentially complicated, and certainly new design effort into an already tight delivery schedule with existing staff is seemingly impossible. No team wants to risk a missed deadline. Secondly, companies must consider the bottom line. Building the cost of new touch screen technology into a product that must be priced to lure buyers away from the competition proves to be difficult. How do existing design teams deliver practical yet delightful multimedia and information displays on a deadline and on a budget?

As Apple has successfully demonstrated, the answer is to become user-centered. Companies must embrace an almost fanatical user-centered approach, focusing the development process on their user interface tools and design process. That, combined with a practical engineering eye focused on rapidly generating high-quality, low-cost user-interface code that is deployable to a wide variety of microprocessors, will allow them to compete and win the hearts and pocketbooks of today’s demanding consumers.

Faced with the expectation of creating a user-centered touch screen display, embedded systems developers are given a daunting list of required tasks. First, they must develop the new human machine interfaces (HMIs). The interfaces need to promote user acceptance, so they must be functional, reliable and aesthetically pleasing. Then the interfaces must be successfully integrated with the prescribed product functions. These tasks must all be accomplished with a powerful array of different systems development tools that assist in developing a product with a cost that will suit the company’s bottom line. The key is to find a means that will allow developers to focus on the usability of the interface and integrate with all of their underlying development tools.

In a typical development of embedded systems, four departments must collaborate. Each department uses a standard tool to get their part of the job done efficiently and correctly. An industrial designer uses CAD to render 2D and 3D ideas and models that incorporate market research results from consumer clinics into the creation, planning, and design of new interfaces — creating what they feel the buyers want for their money.

Human factors engineers then take those recommendations and rely on simulations to gather data about the interaction between the user and the product. They aim to come up with a way to deliver a system interface that makes users maximally productive and satisfied by their interaction with the product.

The systems engineer depends on state tools and modeling tools to design the system to make that interface work given the hardware and software constraints of the product. Software engineers create simulations of the electronics and software and, ultimately, generate the graphics code that will get deployed on the product and interact with the user on a daily basis.

This is where embedded systems development falters. Each department in a design team completes their required tasks with their own tool, which provides exactly what its user needs to get their job done. But the tools are not designed to interconnect, so the teams do not communicate as effectively as they should. Any verbal or written expression of requirements can be easily misinterpreted, forcing teams back to the drawing board. The back-and-forth between departments continues until an acceptable compromise of the needs and desires of each department is met. Approaching deadlines, cost pressures and even performance characteristics often result in a delivered product that is merely a shadow of the original concept.

Fig. 2. Altia-generated graphics code can be deployed onto a final product.

Getting development tools and, consequently, the different development departments on the same page is critical for the delivery of a successful product.

The different groups of an embedded design team work most efficiently when an overarching simulation tool integrates each separate program used within the different areas of embedded systems design. A simulation model built early in the development process serves as an effective means for communicating between development teams. Product development time and effort can be reduced significantly.

By centering efforts on a common model, collaboration between development teams happens early in development. Systems engineers and software engineers can be consulted for requirements to build product behavior simulation models. Human factors engineers and industrial designers can use simulation models for validating intended product behavior, offering a more concise expression than any natural language document.

Software engineers are able to construct simulation models that will retain design efficiencies necessary to allow their code to be embedded into the end product. And by utilizing state-based design tools to express behavior, the software developers are creating the actual product software design while building the simulation model. The software engineering team becomes much more actively involved in the requirements engineering effort and gains the capability to begin high-level and detailed design much earlier in the process.

By employing this model-based development process, new products are more quickly transitioned from specification to implementation. HMI behaviors are clearly demonstrated through simulation, so teams are able to avoid complicated natural language documentation and the exploitation of automated software generation.

A GUI modeling tool with interactive behavior captured clearly through state charts offers the best method for organizing graphical objects for screen arrangements and sophisticated animation. A simulation offers a much better demonstration of complicated interactive behavior than natural language documents. Customers and suppliers are able to provide more constructive feedback on an interactive model.

Ultimately, production software is generated from the model itself so that the opportunity for error in the translation from requirements to product implementation decreases significantly. The effort to translate the requirements to production software also decreases. By creating the GUI in the integrative simulation tool, no manual GUI coding is required. Fonts, raster, graphics primitives, and accelerated graphics control are provided by the simulation tool’s software generation. (See Fig. 1.)

Altia has developed an integration environment with basic and powerful capabilities for simulation and integration of the tools relied upon by different embedded systems development teams. This tool chain provides a unique arrangement of product visualization tools for rendering 2D, 3D, and virtual images plus the embedded software engineering tools for model-based design, simulation, and auto-generation of the embedded code. With Altia tools, users create functional user interface models without graphics programming and then easily combine those models with product functionality. Additionally, multiple models may be joined in co-simulations to build a complete multi-display embedded system. The real efficiency is realized when the models are used for both simulation purposes and automatic software generation for the production hardware. The latter allows the same model code to be designed once and then deployed on a variety of different processors. (See Fig. 2.)

The key to a winning, user-centered design rests in the development team’s ability to maintain a user-centered perspective throughout the product life cycle. By positioning the user interface tool at the center of the design activity, the focal point of the tools remains on the user experience. Tools that offer both simulation and tool integration capabilities provide the connection to other system engineering and industrial design tools, allowing designers and engineers to work in a user-centered fashion while creating new products. The measure of success becomes more than just a new touch screen design delivered on time and on budget, but also the delivery of a winning product.

For more information, email: info@altia.com