Alexa Development Board Runs Linux on Raspberry Pi Compute Module

March 19 2018, 03:10
Gumstix has launched a version of its Linux-driven Chatterbox Alexa Voice Service development board designed for the RPi Compute Module. Designed by Gumstix in Geppetto, and following the Amazon AVS functional design guide, The Chatterbox for Raspberry Pi CM provides a feature rich development platform for Alexa Voice Service projects.

Gumstix has developed a variation on its recently announced Chatterbox for the Colibri iMX7 that is instead powered by a Raspberry Pi Compute Module (see info here). The Linux-powered audio board is similarly designed for developing Amazon Alexa Voice Service (AVS) applications, but offers different features including MIPI-CSI and GPIO connectors.

Like the Chatterbox for the NXP i.MX7 based Colibri iMX7 module, the $116 RPi Compute Module version is designed for creating wake-word or push/hold button activated AVS voice services on devices including smart speakers, smart home and IoT devices, router and gateway devices, sound bars, and set-top boxes. The board complies with Amazon’s AVS Functional Design Guide, and ships with a pre-loaded Linux image.

It appears you can use the new board with either the original Raspberry Pi Compute Module or the Raspberry Pi Compute Module 3 (CM3). The $30, 67.6 x 31mm RPi CM3 computer-on-module has the same 1.2GHz quad-core -A53 SoC as the RPi 3 Model B SBC. (The new Raspberry Pi 3 Model B+ SBC boosts the SoC to 1.4GHz, upgrades to pre-certified, dual-band 802.11ac, and adds USB-based GbE with PoE support.)

The layout and specs are somewhat different on the new Chatterbox. Like the Colibri version, the RPi CM3 Chatterbox includes a 2.5-Watt speaker driver plus an omnidirectional, -42DB microphone. There’s a stereo audio codec, but unlike the Colibri model, there are no audio jacks.
Chatterbox Pi detail views (click image to enlarge)

Since there’s no Ethernet controller on the Compute Module, the board is missing the original model’s 10/100 Ethernet port. However, you get the same TI WiLink 8 module with WiFi and Bluetooth 4.1/BLE. There’s also a U.FL antenna connector.
As before, you get a USB 2.0 host port and micro-USB serial console, but there’s no micro-USB device port, microSD slot, or real-time clock. On the other hand, the new Chatterbox adds a 2-lane, 15-pin CSI-2 camera connector and a 20-pin GPIO connector. Other features include a 5V jack, 2x user pushbuttons, and 2x user LEDs.
The Chatterbox Pi for the Raspberry Pi Compute Module is available for $116.
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