Smart Remote 3 for nRF52 setting a new standard for voice input features and ultra-low power performance in smart remote controls
Nordic Semiconductor has recently released the latest member of their reference design for next generation smart remote controls – nRFready Smart Remote 3 for nRF52 series. This latest reference design takes the Nordic Smart Remote 3 performance to an entirely new level, most especially in 4 categories:
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Unparalleled audio input performance for voice (search/control)
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Outstanding ultra-low power performance
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Available on-chip resources and capacity for introduction of even more features than those already present
- Extensive developer toolsuite for evaluation, test and super-rapid prototyping
The importance of voice
Voice input from remote controls has become increasingly popular with OEMs and ODMs over recent years. The host-side voice recognition software available is now quite sophisticated and reliable and with voice search and control support from some major industry players, some examples are:
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iOS – Siri
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Google – Google Voice
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Microsoft – Cortana
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Amazon – Alexa
Voice input for search and control functionality is already appearing in the remote control market and looks set to become a standard means of interaction for consumers and our home products in the near future.
Unparalleled audio input performance for search and control
The Nordic Smart Remote 3 for nRF52 series attacks the challenge of implementing voice input from a number of angles which in unison yield a high performance solution and offers major power saving benefits. If we start at the sampling end of the chain there are two, on-chip digital mic PDM inputs. With two digital mics connected you have the possibility to sample from each and perform noise and echo cancellation. This naturally leads to a cleaner input sample overall, something that’s cleaner to begin with can withstand greater compression afterwards and thus a reduction into a smaller number of bits for further processing or transmission. After sampling the reference design supports a number of compression techniques currently native CODEC support is supplied for:
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OPUS
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BroadVoice
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ADPCM
All of these have their respective merits/drawbacks, but here we’ll specifically look at OPUS. Opus is a totally open, royalty-free, highly versatile audio codec. It is configurable for very wide rangeof bitrates, from high level/high quality to as low as 6kbs , sampling rates from 8kHz to 48kHz . OPUS offers dynamically adjustable bitrates and adjustable frame sizes. In short OPUS is a very flexible CODEC that is employed in many of the voice input systems in use today. The drawback is that it is demanding computationally. This is why a device of the caliber of the nRF52832 is a must for the supporting of OPUS. The nRF52832 in this reference design is powerful enough to do this and have plenty of horsepower left to support all the other features in the design with capacity to spare.
A true single-chip reference design
The engineers at Nordic worked hard to not only develop a compelling technical solution but also a cost-effective one. This essentially translates into minimum Bill of Material (BOM). The bare minimum of external components is required to implement this design and great use has been made of the on-chip peripherals present on the nRF52832 Bluetooth low energy SoC. Features such as free-space motion sensing naturally require an external device, but all essential features, audio, button matrix input and all computation and application software happens inside a single nRF52832.
Setting the bar for advanced remote control power consumption
Smart Remote 3 for nRF52 has set new benchmarks for power consumption in such a fully featured design. The nRF51 based variant has excellent power consumption figures but the nRF52 variant has reduced these numbers in most areas of operation. Audio capture, process and transmission is reduced by over 60%*. All other modes (keyboard, air motion, connected idle) also see significant energy consumption reductions of 25 to 50%. This all serves to allow longer battery lifetimes and possibly smaller batteries in smaller end products.
*1 mic, ANR off, OPS-CELT-C0-VBR
Enhancing user experience with NFC and over the air updates
In addition to great user interaction features Nordic have tried to add as much as possible to help you create a design with long lasting user appeal. The nRF52 series has on-chip NFC tag-A support. This reference design can take advantage of this with just the addition of a simple and cheap NFC loop antenna. This will allow the remote to be simply paired to another device supporting NFC touch to pair to create an association with another device. A critical feature supported is Over the Air Device Firmware Update (OTA-DFU). OTA-DFU allows for seamless firmware updates to be transferred to the remote control to ensure the very latest firmware is residing in your customer’s remote to enhance and secure their user experience.
Software architecture and development tools
Nordic has listened carefully to customer feedback and has invested significant effort into streamlining the whole firmware architecture in this reference design. Modern techniques for code partitioning have been employed. The result is a modularized architecture that makes configuration a breeze and allows the addition of further modules in a simple way without having to re-work the entire codebase. This assists in making the codebase future-proof and suitable for future Nordic nRF SoCs.
The structured architecture is complemented by a software configuration layer (Keil environment) that enables extremely rapid code configuration at compile time. We believe this is a great help to developers when experimenting and testing (rapidity of execution, power consumption testing and code size measurement) without the need to enter the source code manually.
The is a new Nordic Debug Console which is an option for use during development. When enabled this module allows retrieval of debug information over Segger RTT. Existing debug tools are also supported.
All firmware is delivered as source code* with support for both Keil and GCC compiler environments
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*SoftDevice is delivered as a pre-compiled HEX file
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- Invensense and Vocal.com modules are delivered as precompiled libraries
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- Invensense module (air motion), Vocal.com (active noise cancelling) modules are subject to license from respective companies.
nRFready smart Remote 3 for nRF52 feature set
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Leverages the power of the nRF52 series Bluetooth low energy SoC
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Standard Remote control keyboard interface connected directly to nRF52832 (5x8 supported in hardware with 8x8 supported in software)
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2 digital mics connect directly to nRF52832
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Multi-touch trackpad interfacing directly to nRF52832 (I²C)
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6-Axis motion sensing interfaced directly to nRF52832 (I²C)
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Ultra-low power wake up accelerometer interfaced directly to nRF52832 (I²C)
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IR LED driven directly by nRF52832 using PWM interface
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IR receiver can connect directly to GPIO on nRF52832
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NFC antenna can be connected directly to nRF52832
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Buzzer driven directly by PWM interface on nRF52832
Software support
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Keyboard
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Power management
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Motion sensing
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Wake up on motion
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0, 1 or 2 mic inputs with 3 different compression algorithm options
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IR LED driver
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‘Find Me’ profile for Bluetooth low energy
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‘Battery’ profile for Bluetooth low energy
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NFC tap to pair
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OTA-DFU
In conclusion
The nRFready Smart Remote 3 for nRF52 is a clear winner when selecting a reference design for your next advanced remote control. When you choose the nRFready Smart Remote 3 for nRF52 you get:
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Most complete smart remote control feature set available
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Unparalleled audio input options and performance
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Lowest power consumption available in the market for such a design
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A true single-chip solution
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Room to add still more features for differentiation
Time to try it out?
More on OPUS: https://www.opus-codec.org/