imranduratbegovic/coban1.0

Coban 1.0 is a hardware and software project that turns a soprano recorder into a self-playing instrument. A Flutter app on Android sends musical notes over Bluetooth to a small ESP32-C3 microcontroller mounted on the recorder. The microcontroller then triggers six solenoids that physically press down on the recorder's finger holes, causing the instrument to play the correct notes. The physical build uses a standard Stagg soprano recorder modified to function as a six-hole instrument by permanently blocking the thumb hole and seventh hole. Six push solenoids drive custom 3D-printed flexible valves that replace the instrument's original O-rings. A custom PCB routes all the connections, and a 3D-printed body clamps around the recorder and holds the battery pack, PCB, and solenoids together. The Android app connects to the device over Bluetooth Low Energy and offers a full set of playback controls: saved songs, a manual song creator where you draw fingering patterns directly, a tap-timing recorder, and live hole controls you can trigger in real time. When built with a Gemini API key, the app can also take a photo of sheet music and convert it into a melody automatically. The repository includes a pre-built Android APK that works for manual mode and Bluetooth control without needing an API key. The firmware runs on the ESP32-C3 using the Arduino IDE with the Espressif board package and the ArduinoJson library. The app communicates over a documented Bluetooth protocol, sending small JSON packets that specify the note name, a six-bit fingering mask, duration in milliseconds, and a breath intensity value. The hardware files include the PCB layout in JSON and SVG format and three 3D model files for the main body, solenoid spacers, and flexible valves. The main body prints in rigid PLA, but the valves must print in flexible TPU or TPS because the design depends on the material bending to snap onto the solenoid plunger. The project is released under the MIT License.