# pico-wm8960 — Phase-1 audio-chain bench prototype

A focused bring-up for **Raspberry Pi Pico 2 (RP2350) + SparkFun WM8960 codec breakout** that
validates the new audio path (click → I²S codec → transformer-isolated XLR) before any custom
PCB. **Not** a form-factor firmware — it's the audio-chain validator from the approved plan.

- **Hardware, wiring, shopping list, and the M1–M5 bench milestones:** see
  [`../hardware/PROTOTYPE.md`](../hardware/PROTOTYPE.md).
- **Firmware:** [`code.py`](code.py) — CircuitPython 9.x+.
- **Dependency:** the `adafruit_wm8960` library (`circup install adafruit_wm8960`, or copy
  `adafruit_wm8960/` into `CIRCUITPY/lib`). The SparkFun breakout's onboard 24 MHz oscillator
  supplies the WM8960 MCLK, so no host master clock is needed.

`code.py` boots a steady 120 BPM click (accent every 4) so you can hear the chain and run the
**no-buzz** test (M4). The polymetric track engine and Bluetooth (BM83) drop in once the chain
is proven.