VocalFusion Stereo Dev Kit for Amazon AVS

The XMOS VocalFusion Stereo Dev Kit for Amazon AVS  is a Raspberry Pi specific dev kit to help with the development of “far-field voice capture and processing” applications for the Amazon Alexa Voice Service (AVS). “Far-field voice capture” technology “aims to enable smart devices to recognize distant human speech (usually 1m to 10m).” Through the Amazon AVS technology, it is not necessary to “train” a voice recognition system. The system is ready to go out of the box.

Figure 1: XMOS VocalFusion Stereo Dev Kit for Amazon AVS. (Image source: XMOS)

What’s included:

• Linear array of 4 omni-directional microphones: up to 180° capture, for ‘edge of the room’ applications

• Low-jitter audio clock

• Configurable user input buttons and LEDs

• I²S audio and I²C control connectivity

• USB power, with optional USB 2.0 device audio and control connectivity

• 40-pin Raspberry Pi interface cable (see Figure 3 for the pinout)

What’s not included but needed:

• Raspberry Pi – Digi-Key part number 1690-1025-ND

• Power adapter (minimum 2 A recommended) – Digi-Key part number 1690-1022-ND

• SD card (minimum 16 GB recommended) – Digi-Key part number 1582-1004-ND

• Speaker

• USB keyboard

• USB mouse – Digi-Key part number CH969-ND

• Monitor with HDMI input or Raspberry Pi touchscreen – Digi-Key part number 1690-1007-ND

• HDMI cable – Digi-Key part number Q396-ND (not needed if you are using 1690-1007-ND)

• Ethernet connection with internet connectivity

VocalFusion Stereo Dev Kit block diagram is shown in Figure 2. It includes:

• VocalFusion XVF3500 Voice Processor

• Four MEMS microphones on a separate board

• A micro-USB connector for power (and optionally USB 2.0 device connectivity)

• Extension headers for I²S and I²C control connectivity

• Four general purpose push-button switches

• 13 user-controlled LEDs

• Low-jitter clock source

• An xSYS connector for an xTAG debug adapter

Figure 2: VocalFusion Stereo Dev Kit Block Diagram. (Image source: XMOS)

XMOS provides a straight-forward setup guide. One note to keep in mind, the 40-pin Pi connector is not keyed so it is worth a second check to make sure the connector is placed correctly (see Figure 3).

Figure 3: RPi 40-pin connector.  (Image source: XMOS)

Please see Figure 4 for additional information on the Raspberry Pi pinout.

Figure 4: Raspberry