Building the strongest ecosystem possible means working with partners like LVGL (Light and Versatile Graphics Library), a member of the ST Partner Program that provides free (MIT-licensed) GUI libraries for ST devices, such as our STM32MP microprocessors. Concretely, our collaboration has enabled LVGL to create a library that uses very little memory and can serve cross-platform needs, allowing developers working on our MPUs to reuse their UIs on many other devices. Indeed, ST understands that building a meaningful ecosystem is about providing tools that help developers with edge cases or unique requirements.
The portability and flexibility challenges
The preeminence of TouchGFX
ST offers a free GUI library and tools for our microcontrollers under the TouchGFX banner. Because we are developing it, we can easily integrate it with our other utilities, such as STM32CubeMX, and optimize it for our devices. For instance, we frequently update tools like TouchGFX Designer to support our latest microcontrollers and development boards. And as avid readers of the ST Blog know, we regularly publish updates that optimize memory consumption, introduce innovative frame buffer strategies, and enable richer GUIs on all STM32 microcontrollers. TouchGFX thus remains a critical library for many designers, as the growing number of adopters can attest.
The diverse realities of the wide embedded world
However, we know that TouchGFX will never meet the needs of every single member of the STM32 Community, nor is it supposed to. Some teams must work with microcontrollers from different vendors, which creates an issue when developing a UI that must run across different devices. Developers could, in theory, maintain a separate codebase for each MCU manufacturer, but in practice, this is extremely cumbersome and expensive. Similarly, some designers must work with devices with very different computational capabilities, with projects often straddling the line between MPUs and MCUs. As a result, the memory footprint must be small, and the runtime must require as little computational power to create a foundation for all devices.
Another recent consideration for many developers is that the landscape of embedded GUIs has changed, with many more companies now involved than those developers had to deal with five or ten years ago. Previously, teams were mostly on their own. They had to write their code from scratch and customize every aspect of their application to fit their needs. Today, many companies offer a real-time operating system or an embedded Linux distribution, enabling teams to set up a board and start working on it in minutes. It is a huge time-saver, but it also means that developers of GUI libraries must work closely with all these actors to ensure their offerings are optimized for these new solutions.
The solutions LVGL brings to STM32 developers
More applications
ST and LVGL work closely together to ensure developers can meet these new challenges head-on. It’s about making sure that they get access to the best possible libraries. For instance, we both ensured that LVGL would leverage all the resources on an STM32MP1 and an STM32MP2 to optimize performance. Another example is the ability to use OpenGL on our microprocessors without changes to the LVGL APIs. Developers simply decide whether to use the OpenGL module, and LVGL will then leverage hardware acceleration such as OpenGL or GPU engines available on STM32MP devices. Similarly, the company offers bare-metal solutions for MPUs like the STM32MP13 that can run code without a Linux operating system.
More collaborations
Another reason we work closely with LVGL is their extensive initiatives with many industry partners. One manifestation of this is with Zephyr. ST also works with this famous project, and we aim to support it as best we can, as we’ve shown by bringing our SensorTile.box PRO to the operating system, among other things. However, by its very nature, LVGL can partner with Zephyr to complement what ST offers, including pre-compiled binaries and other integrations that help engineers write a UI faster. Similarly, LVGL works with other members of the ST Partner Program, like Riverdi, which makes STM32 Embedded Displays to hasten development.
More optimizations
In a nutshell, LVGL opens the STM32 developer community to a range of tools, environments, and solutions that can meet exceptional needs, such as those that stem from cross-platform or cross-device applications. That’s why, for instance, we work with LVGL to optimize their library for features in our MCUs like DMA, Chrom-ART, or NeoChrom. If a team needs a unified UI for our MPUs and MCUs, they can be assured it will run optimally on STM32MPx and STM32 devices with minimal codebase changes. Moreover, the company recently moved to a “monorepo” structure to simplify development and is now providing a closed-source UI for a safety-critical application.