Screen vocal keypad
for smart home and buildings

Faster software development and product quality enhanced

Founded in 1955, Hager group, based in Germany, is a leading provider of solutions and services for electrical installations across residential, commercial and industrial buildings. Hager’s range of solutions and services extends across energy distribution, smart home, security systems and building automation.

Hager Group is a worldwide business with over 11,400 employees, generating a turnover of around 2 billion euros with customers in 136 countries worldwide.


Prior to working with, Hager had little experience in developing user-interfaces with graphical displays. Their first prototyping attempt of the alarm keyboard GUI was designed in HTML in order to share the UI/UX specifications with the Marketing team on a PC. Unfortunately, this solution was inefficient as HTML development took too long, and not flexible for fast iterations. As a result, this solution would not be used for product development.

MicroEJ meets Hager’s three top expectactions:

Fast GUI prototyping

Graphical User Interface specification is a complex task and the Hager team wanted a rapid development environment, enabling short iterations for fast decision making across all project stakeholders such as developers and marketing.

Using the MicroEJ SDK and its simulation capabilities, Hager engineers were able to make their virtual device in hours and to quickly develop a first version of the GUI. Thanks to the virtual device, a realistic simulation of user interaction with the display and buttons helped in refining the specification on a daily basis with project members.

Rapid software development  Once Hager developers and the marketing team agreed on the prototype definition, they could reuse the entire Java pre-development code of the GUI application, hence drastically reducing the development effort of the alarm keyboard.

As the electronics for the keyboard were not ready yet, software developers were able to continue developing the virtual device in parallel to the electronics design. The project manager was able to separate software activity from the critical path of the project.

According to Hager, the software development time using MicroEJ software platform was reduced by a factor of 3. The software efficiency, easy execution and the complete set of tools were easy to customize, unlike their other graphical libraries used in the past.
Highly secure and reliable software Hager leveraged the simulation capabilities to intensively test – without hardware – the GUI application software to validate its completeness and robustness.Even if the developers at Hager were used to developing all their products in C language, they migrated towards Java technology with MicroEJ. After a brief training combined with the support of MicroEJ developers, they were very satisfied with the process and the technology.

Thanks to the virtualization and the automatic memory management, developers recognized the MicroEJ solution to be robust while coping with potential small errors unnoticeable by the user. This increased the product’s robustness plus enhanced user experience.

Since the product release in 2015, there were no product returns due to software issues, which offloaded development from after-sales maintenance.

Results overview for Hager RLF660X alarm keyboard


  • GUI development time divided by a factor of 3
  • Decreased maintenance effort
  • Intuitive and appealing GUI with electronic cost structure compatible to Hager expectations
  • Fast adoption of MicroEJ technology for C developers


  • Product release on time
  • High value perception and robustness of the electronic keyboard confirmed by positive feedbacks from customers

Hager electronic keyboard, GUI by MicroEJHager RLF660X: Electronic keyboard with display

  • Radio keypad
  • Device for managing access by code or badge
  • Management of alarm control functions
  • Touch-scan area for information or menu playback
  • peech synthesis and qualitative screen with OLED technology.


“We chose MicroEJ to save time. It is a flexible, reliable and secure solution which we are very satisfied with. We didn’t have any return of this product. This is something very important for us since the quality attests to our brand image.”

Christophe TEILLOT,
Senior Software Engineer at HAGER Group

*For informational purposes only. Information contained in this page describes a specific customer use case and is not legally binding.

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