# mcpositioner

MCP server for controlling an ESP32 dual-axis antenna positioner over WiFi.

Drives two NEMA 17 stepper motors via TMC2209 drivers for theta (polar, 0-180°) and phi (azimuth, 0-360°) rotation. Designed for automated antenna radiation pattern measurement in coordination with a VNA.

## Installation

```bash
# From PyPI (when published)
uvx mcpositioner

# From source
uv run mcpositioner
```

## Hardware

- **ESP32** (any DevKit variant) running the firmware in `firmware/`
- **2x TMC2209** stepper drivers in UART mode
- **2x NEMA 17** stepper motors (0.9° or 1.8° step angle)
- **24V power supply** for motors (5V for ESP32)

See `hardware/` for KiCad schematics showing the wiring.

### Firmware

Build and flash with PlatformIO:

```bash
cd firmware
pio run -t upload
```

The ESP32 advertises itself as `positioner.local` via mDNS. Override with the `MCPOSITIONER_HOST` environment variable if needed.

## MCP Tools

| Tool | Description |
|------|-------------|
| `positioner_status` | Get theta/phi position, moving state, homed state |
| `positioner_move` | Move to absolute theta/phi with optional wait |
| `positioner_home` | StallGuard sensorless homing on one or both axes |
| `positioner_stop` | Emergency stop all motors |
| `positioner_config` | Get/set speed, acceleration, microstepping |

## Prompts

| Prompt | Description |
|--------|-------------|
| `home_positioner` | Guided homing with safety checks |
| `configure_positioner` | Motion parameter tuning guide |
| `measure_pattern_grid` | Cross-server 3D pattern measurement workflow |

## Cross-Server Pattern Measurement

This server controls positioning only. For 3D antenna pattern measurement, use together with [mcnanovna](../mcnanovna/) (VNA MCP server):

1. `positioner_move` (mcpositioner) — position antenna at theta/phi
2. `scan` (mcnanovna) — measure S21 transmission
3. Repeat across theta/phi grid
4. Assemble pattern from collected measurements

The `measure_pattern_grid` prompt provides step-by-step guidance for this workflow.

### Adding Both Servers to Claude Code

```bash
claude mcp add mcpositioner -- uvx mcpositioner
claude mcp add mcnanovna -- uvx mcnanovna
```

## Configuration

| Environment Variable | Default | Description |
|---------------------|---------|-------------|
| `MCPOSITIONER_HOST` | `positioner.local` | ESP32 hostname or IP |

## HTTP API (ESP32 Firmware)

The ESP32 exposes these endpoints:

| Endpoint | Method | Description |
|----------|--------|-------------|
| `/status` | GET | Current position, moving, homed |
| `/move` | POST | `{"theta_deg": 90, "phi_deg": 45}` |
| `/move/relative` | POST | `{"d_theta": 5, "d_phi": 10}` |
| `/home` | POST | `{"axis": "both"}` (or "theta"/"phi") |
| `/stop` | POST | Emergency stop |
| `/config` | GET/POST | Motion parameters |

## License

MIT