LD-110 Lumen Decoder
Immersive Technologies
Semester programme:Open Learning - Main
Client company:TMC, 3Beam
Project group members:Julius Šlepetis
Project description
LD-110 Lumen Decoder / Tape Thingy explores how cassette tape can be used as a physical, understandable, and engaging storage medium for animated LED visuals. The central design challenge is to turn an obsolete audio format into a working interaction system where visitors can see a direct relationship between tape playback, decoded data, and light output.
The project investigates both the technical and experiential sides of this idea: how encoded audio can be reliably read from cassette, how an ESP32-based decoder can translate that signal into LED animations, and how the system can be presented in a way that feels intuitive, playful, and visually credible as a retro-futuristic “hi-fi” device.
The main question is: How can cassette-based data playback be designed into an engaging interactive light demo that makes the underlying technology understandable to visitors?
Context
The project sits in the domain of creative technology, interaction design, retro media, and embedded systems. It combines physical media interaction with digital output by using compact cassette tape as a carrier for encoded visual data. Instead of treating cassette as a nostalgic object only, the project uses it as an active interface: visitors can handle, hear, and observe the medium while it controls an LED display.
The project was developed in an experimental maker context, with public demonstration as an important part of the design process. The intended setting is a demo, exhibition, or maker-fair environment where visitors encounter an unusual device and need to quickly understand what it does. Because the project is meant to capture attention, the user experience is not only about functionality, but also about legibility, curiosity, and the theatrical quality of the interaction.
Technically, the project involves cassette audio playback, signal conditioning, digital decoding on an ESP32, and LED matrix control. From a design perspective, it explores how the physical form, status feedback, sound, and visual output can make an otherwise invisible data process understandable.
The result is positioned between a working prototype, an interactive installation, and a fictional consumer product from an alternate 1980s timeline where people stored light shows next to mixtapes.
Results
The most important outcome of the project is a working cassette-to-LED demo system. The prototype demonstrates that visual data can be stored as audio on cassette tape, played back through a normal tape deck, decoded by custom electronics and firmware, and displayed on a 16×16 LED matrix. This proves the core technical concept: analogue audio tape can act as a physical storage and playback medium for simple digital light content.
The project also produced a clearer interaction direction. Earlier testing and public demonstration showed that visitors understand the concept better when the cassette handling is visible and physical. The tape itself helps explain the system, because people can connect the act of playback to the changing LED output. Audio monitoring also became an important design insight: letting visitors hear the encoded signal makes the invisible data process feel more real. The system becomes less like a hidden computer trick and more like a strange, understandable machine.
Another major result is the development of the LD-110 “Lumen Decoder” concept: a retro hi-fi-inspired enclosure and poster language that frames the prototype as a believable fictional product. This adds value because the styling supports the intended experience. It gives visitors a quick mental model: this is a device that takes tape input and produces light output. The product-like presentation makes the demo more approachable than loose electronics alone.
The technical outcomes include the signal ingestion path, ESP32-based decoding experiments, LED matrix output, audio/data monitoring choices, and firmware/software structure for turning recorded signals into visual playback. These are supported by project documentation, code, prototype media, schematic material, and demo observations.
In terms of validation, the project has been tested in a public maker setting, where visitor reactions and interaction patterns helped shape the design. The findings showed that the concept attracts attention, especially when the physical tape deck, sound, and LED output are all present. The validation also revealed points for improvement: younger visitors with less cassette experience need clearer explanation, the system benefits from stronger status feedback, and the final version should make playback state and decoding activity more visible.
The current TRL position is approximately TRL 5, because the main components have been integrated and tested as a functional prototype in a relevant demo context. If the final version performs reliably during the open day or final public demonstration, it can be argued toward TRL 6, since the system would then be demonstrated as a working prototype in its intended environment.
Overall, the value of the project is not only that it works technically, but that it turns a signal-processing experiment into an understandable and engaging visitor experience. It connects hardware, software, interaction design, and retro-media aesthetics into one coherent demonstrator.