Reference design eases adding voice-control to ZigBee remotes

October 07, 2015 // By Graham Prophet
Addressing what Silicon Labs perceives as a growing demand for voice control in the connected home, this reference design is presented as a cost-effective solution for voice-enabled ZigBee remote controls that reduces the need for external hardware by implementing a high-quality, software-based audio codec into a single-chip wireless SoC.

The software codec is part of Silicon Labs' form-factor reference design for voice-enabled, ZigBee-based and proprietary remote controls, bringing voice operation to TVs, set-top boxes (STBs), over-the-top (OTT) boxes and connected home products.

Silicon Labs' ZigBee Remote Control (ZRC) reference design provides all of the hardware and software needed to develop full-featured, voice-enabled remote controls. The reference design is based on Silicon Labs' EM34x wireless SoCs and ZRC 2.0 Golden Unit-certified software stack, which provides an industry-standard way to implement interoperable, low-power RF remote controls. The reference design includes complete RF layout and design files, an acceleration sensor for backlight control, a buzzer for "find me" capabilities, support for IR control, a digital microphone and the ability to transmit voice commands over RF.

As many "things" for the IoT grow smarter and more connected, it becomes increasingly difficult to incorporate feature-rich user interfaces into small form-factors. Voice enablement (Silicon Labs asserts) is transforming how we control and interface with connected devices by providing an easier, hands-free way to search, explore and experience content and services. By combining the power of voice-over-RF technology and cloud-based speech recognition, voice-enabled remotes free consumers from the line-of-sight, push-button limitations of legacy infrared (IR)-based controls. Silicon Labs' new voice codec technology and complete reference design simplify the process of designing truly smart remotes.

Silicon Labs engineered the reference design to support voice control using either an external hardware codec or the company's software codec technology. The hardware codec reduces the processing load on the EM34x SoC while the software codec trades off increased CPU utilisation for the lowest possible bill of materials (BOM) cost. Both design options meet the stringent voice quality requirements of leading cloud-based speech recognition software providers.

Two Silicon Labs development kits are available for the voice-enabled reference design:

· EM34X-VREVK Voice Remote Evaluation Kit - This basic kit features pre-programmed devices and a simple GUI to demonstrate remote control capabilities including RF, voice commands and legacy IR support.

· EM34X-VRDK Voice Remote Development Kit - Providing an "out-of-the-box" design experience, this full-featured kit simplifies development of the remote control and target devices and comes with an EM34x voice-enabled remote control, USB stick, EM34x development board, EM34x wireless modules and ISA3 debug adapter.