# piNail ESP32-C3 (Single-Nail)

ESP32-C3 firmware for a single-nail piNail controller.

## What changed vs piNail2
- Single physical nail hardware (nail2 UI/API is mirrored for compatibility).
- Wi-Fi onboarding uses captive portal (`piNail-Setup` / `pinailsetup`).

## Hardware target
- Board: ESP32-C3 DevKitM-1 class board.
- Thermocouple ADC: MAX6675 (SPI-like bitbang).
- Relay output: active HIGH relay module.

## GPIO mapping
- Relay: `D10`
- MAX6675 SCK: `D9`
- MAX6675 CS: `D8`
- MAX6675 SO: `D7`

## API compatibility
Implemented endpoints:
- `GET /api/status`
- `GET /api/status/all`
- `GET /api/history`
- `POST /api/power`
- `POST /api/setpoint`
- `POST /api/control`
- `POST /api/flight`
- `POST /api/scheduler`
- `POST /api/pid`
- `POST /api/pid/reset`
- `POST /api/safety/reset`
- `GET /api/heartbeat`
- `GET /api/autotune`
- `POST /api/autotune/start`
- `POST /api/autotune/stop`
- `GET/POST /api/presets`
- `POST /api/preset/<name>`
- `DELETE /api/preset/<name>`
- `GET /api/config`

Built-in web interface:
- `GET /` serves the piNail2-style dashboard UI (embedded static assets).

Not implemented in this firmware:
- True independent dual-zone control (nail2 is API/UI-compatible mirror of nail1).

## Build and flash
```bash
pio run -t upload --upload-port /dev/ttyACM0
pio device monitor -b 115200 --port /dev/ttyACM0
```