All News | Boards | Chips | Devices | Software | Archive | About | Contact | Subscribe
Follow LinuxGizmos:
Twitter Facebook Pinterest RSS feed
*   get email updates   *

Matrix Voice RPi add-on with FPGA-driven mic array relaunches

Jan 22, 2018 — by Eric Brown 2,575 views

Matrix Labs has publicly relaunched its FPGA-driven, 8-mic array “Matrix Voice” voice input add-on board for the Raspberry Pi and Up board for $55, or $65 for a standalone model equipped with an ESP32.

Matrix Labs has shipped its “mostly open source” Matrix Voice Raspberry Pi add-on board for Linux-compatible voice recognition and voice assistant technologies such as Alexa and Google Assistant. The circular board launched in February on Indiegogo, and earned over $130,000 in pledges. The Matrix Voice is now available from the Matrix Labs website for only $10 over the original $45 early bird price.

Matrix Voice, 2018 version, front and back
(click images to enlarge)

Add another $10 and you get a $65 standalone version with Espressif’s ESP32 MCU SoC. The $65 model does not require an attached RPi board, and supplies WiFi and Bluetooth.

The Matrix Voice has been redesigned compared to the prototype shown last February, but the feature set appears to be the essentially the same except for a slight upgrade to the Spartan 6 FPGA. The board continues to support all Raspberry Pi B+ or newer 40-pin ready Raspberry Pi models, as well as the Raspberry Pi Zero (and presumably the Zero W and new Zero WH). It also supports Aaeon’s x86-based RPi clone, the UP board. In addition to running Raspbian and Debian, the Matrix Voice now supports Android Things, which has recently added enhanced support for Google Assistant.


Since the Matrix Voice was announced almost a year ago, we have seen a number of voice assistant add-on solutions for the Raspberry Pi, including Seeed’s $25 ReSpeaker 4-Mic Array for Raspberry Pi and JOY-iT’s Google Assistant focused Talking Pi add-on, which launched last week for $15. The Matrix Voice offers a more advanced MEMs microphone array than most, however, with 7x radially deployed 8MEMSMP34DB02 audio sensor digital microphones plus an eighth mic in the middle. (The prototype had 7x mics total including the center mic.)

The array is powered by a Xilinx XC6SLX9 Spartan 6 FPGA that runs algorithms for voice, Beamforming, AEC, de-reverberation, and noise cancellation. This is an upgrade from the originally announced XC6SLX4 model, offering more than twice the number of logic cells (9,152) and I/O (200), and twice the number of DSP slices (16).

Compared to the earlier Matrix home automation and surveillance hub and FPGA-driven Matrix Creator RPi add-on board, the Matrix Voice has fewer general purpose interfaces for home automation integration. However, you do get a 24-pin GPIO header allocated to 16x GPIOs, 2x I2C lines, and power, as well as a 40-pin interface connector that extends the Pi’s I/O. Other I/O includes UART, SPI, and I2S.

The Matrix Voice supports the FPGA with 64MB RAM and 64Mbit flash. Like Seeed’s ReSpeaker 4-Mic Array, you get an EverLoop LED ring for synchronization with audio, in this case offering a radial array of 18 RGBW LEDs instead of 12.

The bottom of the Voice board provides a location for an optional ESP32 module, available on the standalone edition. This also provides 2.4Ghz 802.11b/g/n and Bluetooth 4.0 LE.

Further information

The Matrix Voice is now shipping to Indiegogo backers, and has relaunched publicly for $55 or $65 (standalone with ESP32). More information may be found on Matrix Labs’ Matrix Voice product page, which offers a link to a shopping page. More details are available on GitHub

(advertise here)

Print Friendly, PDF & Email

One response to “Matrix Voice RPi add-on with FPGA-driven mic array relaunches”

  1. Andrés Calderón says:

    Are 8 microphones, one microphone at the center, 7 radial microphones.

Please comment here...