Hobbyists that are trying to learn about electronics often get started by writing firmware for a simple embedded system, blinking some LEDs, and maybe working on their soldering skills. But once these sorts of foundational skills have been acquired, they often don’t know where to go from there. After getting past the basics, what should someone actually use their newfound talents to do?
One good option would be to build a device created by Hackaday.io user b.sverdlyuk called Lilka. It has a relatively simple hardware design that is accessible to beginners, yet it is also a great platform for learning. This handheld can be hacked to play retro games, log data, play music — and yes, it can also run Doom.
The reverse side of the board (📷: b.sverdlyuk)
Lilka is a $15 open source handheld console built around an ESP32-S3 module. That design choice makes it especially approachable — builders can assemble it using widely available components while still ending up with a surprisingly capable system. The ESP32-S3 provides dual-core processing at 240 MHz, along with generous memory for a microcontroller platform, enabling far more complex applications than a typical beginner board.
The device runs FreeRTOS through Espressif’s ESP-IDF framework, giving developers access to multitasking and networking features. On top of that sits the Lilka SDK, which abstracts away low-level hardware details into simple function calls for graphics, audio, and input. This allows beginners to focus on building projects rather than wrestling with SPI drivers or timing-sensitive code.
The final layer is KeiraOS, the custom operating system that ties everything together. It provides a user-friendly interface, a menu system, and support for apps and background services. Apps handle user interaction and rendering, while services run quietly in the background — maintaining Wi-Fi connections or serving a web interface, for example. This structure introduces learners to real-world software architecture concepts without overwhelming them.
Lilka can be used for a wide range of applications (📷: b.sverdlyuk)
Lua is the system’s primary programming language, offering a lightweight, script-based workflow where users can simply drop files onto an SD card and run them instantly. For those who want more performance, C++ is available, along with an experimental system for dynamically loading compiled applications without reflashing the device.
Lilka encourages experimentation with hardware through its exposed GPIO pins. Users can connect sensors, relays, or modules like ultrasonic distance sensors and soil moisture probes, building interactive projects that interact with the physical world.
By combining accessible hardware with a surprisingly deep software stack, Lilka provides a natural next step for hobbyists ready to move beyond blinking LEDs. It’s not just another throwaway project — it’s a compact playground for learning embedded systems in a hands-on and engaging way. Check out the full project write-up for all the details you need to build your own.
