The software
The firmware and the app are the same whichever path you take. You install them once the hardware is together.
Breadboard path
Breadboard / hand-wired
Assemble the parts on a breadboard with Dupont wires. No electronic board fabrication required.
Breadboard path
BOM, breadboard version
Everything needed for the breadboard path. Indicative 2026 prices, shipping excluded.
| Component | Suggested reference | Qty | Ind. price |
|---|---|---|---|
| ESP32-S3 N8R8 | ESP32-S3-DevKitC-1 N8R8 | 1 | ~€12 |
| NFC reader | PN532 module (SPI mode) | 1 | ~€6 |
| I2S audio amplifier | MAX98357A | 1 | ~€5 |
| Speaker | 4 Ω 3 W (40-50 mm) | 1 | ~€3 |
| microSD reader | SPI breakout module 3.3 V | 1 | ~€2 |
| microSD card | Class 10 / U1, 8-32 GB, FAT32 | 1 | ~€6 |
| RGB LED strip | WS2812B, 8 LEDs | 1 | ~€3 |
| Rotary encoder | EC11 type with push button | 1 | ~€1 |
| Push buttons | Momentary buttons | 4 | ~€1 |
| NFC tags | NTAG213/215/216 (Type 2) | ≥5 | ~€5 |
| Breadboard + wires | Breadboard + Dupont wires | 1 set | ~€6 |
| LED capacitor | Electrolytic 100-1000 µF | 1 | ~€0.20 |
| USB power supply | USB 5 V brick (1 A min.) + cable | 1 | ~€5 |
The firmware uses no screen. For a portable build, a LiPo Rider module (planned for the 3D-printed enclosure, still being designed) powers the MusicBox from a LiPo battery. In-firmware battery management is still to come.
On this path the enclosure is yours to build: there is no STL file for a breadboard assembly.
Wiring
Connecting the components
GPIO pinout per peripheral, verified against the firmware code. Logic levels at 3.3 V.
| Peripheral | Bus | Pins (GPIO) |
|---|---|---|
| PN532 NFC | SPI | SCK 14 · MOSI 13 · MISO 12 · SS 15 · RST 3 |
| microSD card | SPI | SCK 18 · MOSI 17 · MISO 8 · CS 5 |
| MAX98357A audio | I2S | DIN 40 · BCLK 41 · LRC 42 |
| WS2812B LED strip (×8) | RMT | DATA 16 |
| EC11 encoder | PCNT | CLK 9 · DT 11 · SW 10 |
| Action buttons ×4 | GPIO | 45 · 46 · 47 · 48 (active LOW) |
What's next?
Development board
An all-in-one dedicated board by HermitX. Ships with the NFC antenna, a 3 W speaker and an NTAG215 card.