dcknightdc/usb_4_mic_array

ReSpeaker 4 Mic Array with builtin VAD, DOA, AEC, Beamforming & NS

ReSpeaker USB 4 Mic Array

Available at Seeed

The ReSpeaker USB 4 Mic Array is the successor of the ReSpeaker USB 6+1 Mic Array. It has better built-in audio processing algorithms than the 6+1 Mic Array, so it has better audio recording quality, although it only has 4 microphones.

Features

• 4 microphones
• 12 RGB LEDs
• USB
• built-in AEC, VAD, DOA, Beamforming and NS
• 16000 sample rate

Usage

Audacity is recommended to test audio recording.

Install DFU and LED control driver for Windows

On Linux and macOS, the USB 4 Mic Array will just work. On Windows, audio recording and playback will also work without installing a driver. But in order to upgrade the device's firmware or to control LEDs an DSP parameters on Windows, the libusb-win32 driver is required. We use a handy tool - Zadig to install the libusb-win32 driver for both SEEED DFU and SEEED Control (the USB 4 Mic Array has 4 devices on Windows Device Manager).

Make sure that libusb-win32 is selected, not WinUSB or libusbK

Device Firmware Update

The Microphone Array supports USB DFU. We have a python script - dfu.py to do that.

pip install pyusb
python dfu.py --download new_firmware.bin       #  with sudo if usb permission error

firmware	channels	note
1_channel_firmware.bin	1	processed audio for ASR
6_channels_firmware.bin	6	channel 0: processed audio for ASR, channel 1-4: 4 microphones' raw data, channel 5: playback
6_channels_firmware_6.02dB.bin	6	same as 6_channels_firmware.bin, but 4 microphones have a 6.02dB gain
6_channels_firmware_12.04dB.bin	6	same as 6_channels_firmware.bin, but 4 microphones have a 12.04dB gain
48k_1_channels_firmware.bin	1	48k sample rate, 1 input channel
48k_6_channels_firmware_6.02dB.bin	6	s48k sample rate, 1 input channel, 6.02dB gain

How to control the RGB LED ring

The USB 4 Mic Array has on-board 12 RGB LEDs and has a variety of light effects. Go to the respeaker/pixel_ring to learn how to use it. The LED control protocol is at respeaker/pixel_ring wiki.

Tuning

There are some parameters of built-in algorithms to configure. For example, we can turn off Automatic Gain Control (AGC):

python tuning.py AGCONOFF 0i6_firmware.bin

To get the full list parameters, run:

python tuning.py -p

Realtime sound source localization and tracking

ODAS is a very cool project to perform sound source localization, tracking, separation and post-filtering. Let's have a try!

1. get ODAS and build it

sudo apt-get install libfftw3-dev libconfig-dev libasound2-dev
git clone https://github.com/introlab/odas.git --branch=dev
mkdir odas/build
cd odas/build
cmake ..
make

2. get ODAS Studio from https://github.com/introlab/odas_web/releases and open it.

The odascore will be at odas/bin/odascore, the config file is at odas.cfg. Change odas.cfg based on your sound card number.

    interface: {
        type = "soundcard";
        card = 1;
        device = 0;
    }

3. upgrade your usb 4 mic array with 6_channels_firmware_6.02dB.bin (or 6_channels_firmware.bin, 6_channels_firmware_12.04dB.bin) which includes 4 channels raw audio data.