Problem / Solution
SumUp is a leading global financial technology company supporting businesses of all sizes with easy‑to‑use and affordable financial tools.
With their new Solo Lite card reader, SumUp set out to design a device that is not only lightweight and affordable, but also reliable, stylish, and seamless in day‑to‑day business use
The primary challenge was to create a smooth, responsive user interface for a compact device running Zephyr RTOS on embedded hardware, one that could handle dynamic UI updates, multilingual flows, and future‑ready features like QR code receipts, all while conserving system resources.
After evaluating alternatives, the development team chose LVGL as the UI framework. With native Zephyr support, a flexible graphics API, and an open‑source license, LVGL provided the perfect fit.
LVGL was a no‑brainer for the Solo Lite project. We needed something lightweight, fast, and well‑integrated with Zephyr. LVGL gave us the control and speed we needed on constrained hardware. The cherry on top is its QR code generation feature.
Key Results
Zephyr-Native Integration
LVGL’s first‑class Zephyr RTOS support enabled seamless integration with SumUp’s real‑time embedded stack — no hacks or workarounds needed.
Crisp, Polished UI on Minimal Hardware
Anti‑aliased rendering and compressed fonts allowed SumUp to build a crisp, attractive, and responsive touchscreen interface on low‑resource embedded hardware.
Efficient Image Handling
Loading images directly from flash in CF_8_INDEXED format saved RAM and sped up rendering, no decompression needed.
No Licensing Headaches
LVGL’s open-source MIT license allowed the SumUp team to adopt and integrate it freely, without the need for commercial negotiations, helping them move fast and stay focused on product quality.
Future-Proof Foundation
With LVGL already powering Solo Lite, SumUp can easily extend the same UI toolkit to future device generations or accessories, improving maintainability across its embedded product line.
Technical Wins
- Zephyr RTOS Compatibility: Native LVGL support ensured full compatibility with SumUp's firmware architecture.
- Device-Generated QR: Real‑time QR code display for payments, receipts, and morehandled entirely on‑device (QR receipts planned for future updates).
- Efficient Rendering: Fast performance with low memory footprint, optimized for long battery life.
- Multilingual UI: Built‑in support for internationalization/localization with Unicode fonts (RTL layout support not currently used).
- Developer Velocity: Simple APIs and rich documentation enabled rapid prototyping and fast iteration cycles.
Technical Specifications
Future Projects
While there are no confirmed plans for LVGL in future SumUp products, the team welcomed LVGL’s upcoming UI Editor, showing special interest in real‑time design previews and usability testing.
Ready to transform your UI?
If you're developing embedded fintech products or facing similar challenges with performance, portability, or licensing, LVGL can help.
Discover how our open-source, high-performance framework can accelerate your UI development and unlock new product possibilities.