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6.4.9 Sound Localization

Last Version: 12/09/2025

This guide demonstrates how to implement sound source localization using the iFlytek M260C 6-Microphone Array Board. The hardware detects the direction of sound sources and outputs an angle between 0° and 360°.

Hardware Specifications​

Product: iFlytek Co-branded Far-field Microphone Array (6-Mic)
Model: M260C Voice Interaction Module
Official Link: Product Page

It outputs an angle between 0° and 360°.

Hardware Connection​

Connect the microphone array to your system as shown below:

Device Configuration​

To allow your system to recognize the microphone array, you need to create a device rule

sudo su

echo  'KERNEL=="ttyACM*", ATTRS{serial}=="0004", ATTRS{idVendor}=="1a86", ATTRS{idProduct}=="55d4", MODE:="0777",SYMLINK+="wheeltec_mic"' >/etc/udev/rules.d/wheeltec_mic.rules

udevadm control --reload-rules
udevadm trigger

Verify the configuration:

ls /dev/wheeltec_mic -lh

Expected successful output:

Launching Sound Localization​

Start the microphone node:

ros2 launch br_sensors ring_mic.launch.py

Testing the Functionality

  1. Speak the default wake-up phrase "小微小微" / "Xiao Wei Xiao Wei" (in any direction).
  2. The system detects the wake-up phrase and outputs the angle of the sound source (0° to 360°)

Example terminal output:

Note:

  • The default wake-up phrase is "Xiao Wei Xiao Wei". You can change it by referring to the official hardware documentation.
  • A trigger flag is set to 1 when wake word is detected, then resets to 0
  • Use this flag to determine wake phrase detection in your subscribers

Topic Subscription​

Topic name: angle_topic

Below is a simple Python script to subscribe to the angle_topic and display the angle and wake-up flag:

import rclpy
from rclpy.node import Node
from std_msgs.msg import Int32MultiArray

class AngleSubscriber(Node):
    def __init__(self):
        super().__init__('angle_subscriber')
        self.subscription = self.create_subscription(
            Int32MultiArray,
            'angle_topic',
            self.listener_callback,
            10
        )

    def listener_callback(self, msg):
        if msg.data and len(msg.data) >= 2:
            angle = msg.data[0]
            trigger_flag = msg.data[1]
            self.get_logger().info(f"Received angle: {angle}, trigger: {trigger_flag}")

def main(args=None):
    rclpy.init(args=args)
    node = AngleSubscriber()
    rclpy.spin(node)
    node.destroy_node()
    rclpy.shutdown()

if __name__ == '__main__':
    main()

Save the script as angle_sub.py

Source your ROS 2 environment and run the script:

source /opt/bros/humble/setup.bash
python3 angle_sub.py

The subscriber will continuously print received angle and trigger data whenever the wake-up phrase is detected.