ReSpeaker 4-Mic Array for Raspberry Pi is a quad-microphone expansion board for Raspberry Pi and it has been designed for AI assistant and voice applications. The board will give Raspberry Pi board the ability to do Voice Activity Detection (VAD) aka “hot word” detection, estimate Direction of Arrival (DoA) and show the direction via the LED ring, just like Amazon Echo or Google Home. The board can be used in robotics or in smart homes, IoT scenarios, and conference rooms, and can be customization to add new modules.
Different from ReSpeaker 2-Mics Pi HAT, this board has been developed based on AC108, an integrated quad-channel ADC (Analog to Digital Converter) with I2S/TDM (Time Division Multiplexing) output transition which will give you a high definition voice capture functionality. The board has been developed on the Cirrus Logic WM8960, a low power stereo codec which will provide 1W per channel into 8W loads. The board also has a 3.5 mm audio jack or JST 2.0 speaker connector for audio output. It is compatible with and will support Raspberry Pi Zero and Zero W, Raspberry Pi B+, Raspberry Pi 2 B and Raspberry Pi 3 B.
Respeaker 4-Mic Array board specifications:
X-Powers AC108 quad-channel ADC with I2S/TDM output transition
2x Grove interfaces (1x I2C, 1x GPIO port using pins 12 & 13)
40-pin Raspberry Pi compatible header
Misc – 12 LEDs (APA102) connected over SPI, GPIO5 enables power
Dimensions – 65mm x 65mm x 9mm
Weight – ~20 grams
For details about getting started guide & Google Assistant tutorial do check out their GitHub account, where you can also download the hardware design files (PDF and Eagle).