# Hardware Wiring

## Waveshare 7.5" V2 e-ink → ESP32

| Display pin | ESP32 GPIO | Notes |
|---|---|---|
| BUSY | 4 | Input — display signals when busy |
| RST | 16 | Reset |
| DC | 17 | Data/command select |
| CS | 5 | SPI chip select |
| CLK | 18 | SPI clock (hardware SPI) |
| DIN | 23 | SPI MOSI |
| GND | GND | |
| VCC | 3.3 V | Do **not** use 5 V |

> These pin assignments match `main.cpp`. If you need to remap them, change
> the `PIN_*` defines at the top of the file — the SPI CLK and DIN pins (18, 23)
> are hardware SPI and cannot be freely remapped without switching to software SPI.

## Power

- Display: powered from the ESP32 3.3 V rail. Current draw during refresh is
  ~30 mA peak — within ESP32 rail limits for a single display.
- ESP32: power from USB (5 V). For permanent installation use a 5 V USB wall
  adapter rated ≥ 1 A.

## Audio input

| Source | Connection | Notes |
|---|---|---|
| Mixing desk | Line-out → USB audio interface → PC USB | Cleanest signal; recommended |
| Microphone | USB condenser → PC USB | Use if mixer feed not available |

Whisper performs best with a clean, low-noise signal. A direct line feed from
the mixing desk eliminates room echo and background noise.
