Embedded User Interface

Welcome everyone!

Today we're going to start a new serie on display integration in Linux!

This time, we'll see how to integrate a custom ILI9881C based display panel to Linux, in Torizon OS.

The serie will be split like this:

• Presentation + Setting up the DTS

• Driver modification

Infrabase's build infrastructure — based on BitBake and OpenEmbedded, but optimized for simplicity and flexibility — continues to evolve, with numerous improvements since our initial release. Today’s guide walks through source-level debugging of an LVGL application, all inside a QEMU/virt64 environment. No hardware needed — just a modern Linux host and developer tools

Today we’ll dive into the execution of an LVGL application and explore the LVGL library internals — all inside a QEMU/virt64 emulated environment. Yep: no hardware required. 🙂

What you’ll do

• Build the default Infrabase environment and QEMU.

• Enable debug symbols for your LVGL app and the LVGL library.

• Launch the emulated GUI and attach VS Code + gdb-multiarch.

QR codes have become a ubiquitous way to encode and share information, URLs, contact details, configuration parameters, and more. With LVGL, embedding a QR code into your embedded UI is straightforward. In this post, we’ll explore how to use QR codes in LVGL, discuss the limits of QR code sizing on embedded displays, and take a step back to reflect on the design philosophy behind these clever square patterns.

Using QR Codes in LVGL

Starting from LVGL v8, the library includes a built-in widget for generating and displaying QR codes.

Here's a simple example:

lv_obj_t * qr = lv_qrcode_create(lv_scr_act(), 100, lv_color_black(), lv_color_white());
lv_qrcode_update(qr, "https://www.edgemtech.com");

This snippet creates a 100x100 pixel QR code in black on a white background. The lv_qrcode_update function encodes the string into the QR pattern.

Welcome to this second part of the great quest to add a custom format to LVGL 9.x!

Last time, we saw how to define our custom pixel format and how to add a way to blend it using LVGL. At this point, we are able to draw basic objects with our custom pixel format.

This time, we'll see how to patch LVGL to be able to transform our objects. This includes:

• Scaling

• Rotation

• Skewing