# Sound Direction of Arrival (DoA)

This example demonstrates how to use the microphone array to detect the Direction of Arrival (DoA) of speech. The robot uses the FastAPI endpoint to get DoA information, calculates the position of the sound source, transforms it into world coordinates, and automatically looks towards the speaker.

**How it works:**
1. Continuously polls the `/api/state/doa` endpoint to get speech direction
2. When speech is detected, calculates the 3D position of the sound source
3. Transforms the position from head coordinates to world coordinates
4. Commands the robot to look at the speaker using `look_at_world()`

**Features:**
- Automatic detection of robot IP (local or wireless)
- Threshold-based filtering to avoid excessive head movements
- Real-time transformation from head to world coordinates

```python

import time

import numpy as np
import requests

from reachy_mini import ReachyMini

def main() -> None:
    """Continuously monitor audio input and orient the head toward the speaker."""
    with ReachyMini(log_level="DEBUG", automatic_body_yaw=True) as mini:
        # Get the robot IP address
        robot_ip = "localhost"
        status = mini.client.get_status()
        if status.wireless_version and status.wlan_ip:
            robot_ip = status.wlan_ip

        doa_url = f"http://{robot_ip}:8000/api/state/doa"

        last_doa = -1
        THRESHOLD = 0.004  # ~2 degrees

        while True:
            # Get DoA from FastAPI endpoint
            try:
                response = requests.get(doa_url, timeout=1.0)
                response.raise_for_status()
                doa_data = response.json()

                if doa_data is None:
                    print("  No DoA data available (audio not initialized)")
                    time.sleep(0.5)
                    continue

                angle = doa_data["angle"]
                speech_detected = doa_data["speech_detected"]

                print(f"DOA: angle={angle:.3f} rad, speech_detected={speech_detected}")

                if speech_detected and np.abs(angle - last_doa) > THRESHOLD:
                    print(f"  Speech detected at {angle:.1f} radians")
                    p_head = [np.sin(angle), np.cos(angle), 0.0]
                    print(
                        f"  Pointing to x={p_head[0]:.2f}, y={p_head[1]:.2f}, z={p_head[2]:.2f}"
                    )
                    T_world_head = mini.get_current_head_pose()
                    R_world_head = T_world_head[:3, :3]
                    p_world = R_world_head @ p_head
                    print(
                        f"  In world coordinates: x={p_world[0]:.2f}, y={p_world[1]:.2f}, z={p_world[2]:.2f}"
                    )
                    mini.look_at_world(p_world[0], p_world[1], p_world[2], duration=0.5)
                    last_doa = angle
                else:
                    if not speech_detected:
                        print("  No speech detected")
                    else:
                        print(
                            f"  Small change in DOA: {angle:.1f} rad (last was {last_doa:.1f} rad). Not moving."
                        )
                    time.sleep(0.5)

            except requests.RequestException as e:
                print(f"  Error fetching DoA: {e}")
                time.sleep(0.5)

if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        print("Exiting...")
```