Owl mainboard

OwlTunes

Your music, one turn away.
A Spotify remote with a round AMOLED face and a rotating ring. It charges on your desk and goes with you in your pocket.

Website | Setup guide | System design | Hardware

OwlTunes controls the music that is already playing on your phone, laptop or speakers. Turn the ring to change the volume, tap the cover to pause, press an ear to skip. Drop it on its perch and it becomes a desk display that charges while it shows what is playing.

Spotify switched off every Car Thing in December 2024. Nobody can do that to OwlTunes: the firmware, boards and enclosure are open source, it talks to Spotify's Web API directly over Wi-Fi, and Bluetooth media keys keep working when there is no internet.

The device

How you use it

It also browses your playlists and library, searches, manages the queue and moves playback between your Spotify Connect devices.

What it looks like

The screens below come from the desktop simulator, which runs the same UI code as the firmware.

Inside

A 4-layer main board (KiCad 10, assembled by JLCPCB) inside a printed nylon enclosure (build123d, MJF PA12). The ring carries magnets that a Hall sensor on the board reads, and a small linear motor gives each detent its click. Every board passes ERC, DRC and a check against the enclosure's mechanical contract in CI.

The renders on this page are made from the same files: the enclosure and board meshes go into Blender with tools/render.sh, and the screen shows the simulator's output. The album art is a generated placeholder. The renders were computed on the DelftBlue supercomputer of the Delft High Performance Computing Centre (DHPC, https://www.tudelft.nl/dhpc), and the owl v0 renders on a TU Delft EWI compute server.

Owl v0

The first owl to be built is owl v0: the same face, ring, ears and beak, built round Waveshare's ESP32-S3-Touch-AMOLED-1.75 kit, which brings the display, the ESP32-S3, USB-C and the battery charger, so there is no board to order. Six nylon prints hold it, a Hall sensor module reads the ring's magnets, and tact switches sit under the ears and the beak. It has no perch, haptics or light sensor yet, and it is 19.7 mm deep. kit-owl.md has the parts, wiring and assembly.

Status

• Firmware: Wi-Fi setup, Spotify linking and playback control run on an ESP32-S3 dev board against a real Spotify account, and are tested on the host and in QEMU. Display and touch drivers for the rev A board and the Waveshare AMOLED kit build in CI and wait for first light.
• Owl v0: the owl built round the Waveshare AMOLED kit, with the ring, ear and beak buttons and a 400 mAh cell, ready to order and print (kit-owl.md).
• Hardware rev A: main board and perch board designed and checked; ordered after owl v0.
• Enclosure v1: owl, ring, bezel and perch ready for printing, with the face built around the panel's 52.6 mm cover glass.
• Next: owl v0 assembled and brought up, the button and ring drivers, then rev A.

Read the system design for the full picture and docs/hardware for the boards.

Set it up

OwlTunes needs Spotify Premium and your own free Spotify developer app (client ID). It uses the Authorization Code flow with PKCE, so no client secret is stored on the device or in this repository. Open the setup page in Chrome or Edge, connect the owl over USB, add your Wi-Fi networks and client ID, and log in with Spotify. The setup guide walks through every step.

Build it

Commands (Linux with CMake 3.22+, Ninja and a C compiler)

What	Command
Unit tests (with sanitizers)	tools/test_host.sh
Simulator screenshot tests	tools/sim.sh
Interactive simulator (needs libsdl2-dev)	cmake -S sim -B build/sim-sdl -G Ninja -DOWL_SIM_SDL=ON && cmake --build build/sim-sdl && build/sim-sdl/owl_sim sdl
Firmware (ESP-IDF v6.1 activated)	tools/firmware.sh build
Firmware for the Arduino Nano ESP32, and flashing it	tools/firmware.sh build nano_esp32, then tools/firmware.sh flash nano_esp32
Firmware for the owl's rev A board or the Waveshare ESP32-S3-Touch-AMOLED-1.75 kit (display and touch; not yet run on hardware)	tools/firmware.sh build owltunes_reva or tools/firmware.sh build waveshare_amoled_175, then flash with the same board name
Hardware tests on the Nano ESP32 (board on USB)	tools/hil_nano.py --wifi; with a linked board and your consent, tools/hil_spotify.py --real-account
Firmware in the QEMU emulator	tools/qemu_smoke.sh
Setup protocol in QEMU, including a real HTTPS call to Spotify	tools/qemu_prov_test.py
Setup site: unit and browser tests (Node.js 22)	cd web && npm ci && npm test && npm run e2e
Setup site: local development server	cd web && npm run dev
Enclosure tests and exports	see enclosure/README.md
Hardware checks (KiCad 10)	tools/hw/check_all.sh
Product renders (Blender 5.2, kicad-cli, uv)	tools/render.sh
Regenerate the UI fonts (needs Node.js)	tools/gen_fonts.sh

The UI font is Inter (SIL Open Font License, see firmware/components/owl_ui/fonts/LICENSE-Inter.txt).

Licences

• Software: MIT
• Hardware and enclosure designs: CERN-OHL-P-2.0

Not affiliated with Spotify

OwlTunes is an independent, non-commercial project. It is not affiliated with, endorsed by or sponsored by Spotify. Spotify is a trademark of Spotify AB.