ULP Wireless Update

Speak up for remote control

Speak up for remote control

Voice activation is starting to permeate all areas of work and home including remote controls

Voice assistants are established in smartphones and speech-activated smart speakers are flooding the market, now the humble remote control is catching up

Voice control has finally moved from the realms of science fiction to science fact. It’s nearly 50 years since HAL 9000’s spine-chilling response of “I’m sorry Dave, I’m afraid I can’t do that” to the human spacefarer’s spoken request to “open the pod bay doors” during the sci-fi movie 2001: A Space Odyssey. Yet it’s only in the last few years that iOS’s voice assistant ‘Siri’ and Android equivalents such as ‘Robin’ have become established.


Fortunately, today’s voice assistants are a lot friendlier than the malevolent computers from yesterday’s movies and politely inform smartphone users what the weather’s like or add important meetings to the calendar. Moreover, voice-activated control is starting to permeate other areas of work and home. Siri has migrated to Apple’s desktop computers, and devices such as Amazon’s Echo, a voice-activated smart speaker which will, among other things, stream music on command and access online encyclopaedia articles, are commercially available. Google Home is a competing device that answers to the name Alexa and similarly responds to questions about traffic congestion while also controlling smart devices around the home such as thermostats and lights.


The market is still immature; some devices among the dozens now on the market are limited in capability and introduce unacceptable latency. And many users are self-conscious when talking to a gadget, causing unusual voice intonation. For products designed to interact with natural speech this can cause problems. But the technology is developing rapidly, and voice control is here to stay. And the next device to gain the capability is the modest remote control.


Adding voice recognition to a remote control eliminates button pushing which can be slow, error ridden, and particularly taxing in the typical darkened home-cinema room. In contrast, voice commands are simple, rapid, and not reliant on the TV’s predetermined menu structure - making the process of controlling the set far more relaxed.


Remote revolution

Remote controls have recently been undergoing a revolution. Venerable infrared (IR) remotes have served well since the 1970s and will continue to find a niche where cost and simplicity are important. But modern remote controls increasingly adopt wireless connectivity such as Bluetooth low energy.


Compared with IR, Bluetooth low energy offers lower latency, bidirectional connection, non-line-of-sight control, and extended range compared to IR. The technology allows devices to be controlled through obstacles and even interior walls. And RF has sufficient bandwidth over a bidirectional link to support advanced user interfaces while consuming modest battery power and meeting mass-market cost constraints. These are major advantages for consumers accessing the huge array of digital content typically stored on home entertainment devices.


However, adding voice capability to a remote control is not simple: The device must receive and understand the instruction (often among considerable background noise), digitize, interpret and compress the information, and transmit it to the TV all in a matter of a few hundred milliseconds. (Some engineers suggest it might be easier for the consumer to talk directly to the TV, after all, modern sets include powerful electronics well suited to the task. The key issue is privacy; to work seamlessly, the set would need to listen for commands continually through its built-in microphone - a capability that understandably concerns those who’d rather keep their conversations hidden from an Internet-connected smart appliance. In contrast, a remote control can be activated to receive a voice command via a single button press and then switched off immediately.)


Fortunately, today’s powerful Bluetooth low energy Systems- on-Chip (SoCs), such as Nordic Semiconductor’s ARM M4F microprocessor-powered nRF52832, are more than capable of supporting voice recognition. Better yet, the SoCs modest power consumption enables voice control without rapidly draining batteries.


To make it easier for engineers to design voice-activated remote controls, Nordic recently introduced the ‘nRFready Smart Remote 3’ based on the nRF52832 SoC. According to Nordic’s John Leonard: “The nRF52832’s extra processing power allows the new reference design to support audio functionality including two digital microphones and all required signal processing in a single-chip implementation for state-of-the-art voice input search and control of home media devices.” Among other functions, such capability allows for on-chip noise and echo cancellation, resulting in much cleaner sampling of audio streams.


The nRFready Smart Remote 3 for nRF52 Series supports a range of popular audio compression formats including Opus, Broadvoice, and ADPCM. It comes complete with all the necessary embedded software to complete a voice remote control design, including host-side support software for Linux boxes.


The Smart Remote 3 is about more than just voice input though, offering a comprehensive range of functionality including keyboard matrix, six-axis motion sensing, multitouch trackpad, infrared LED for legacy appliance control, NFC Touch-to-Pair, and on-board buzzer implementing the Bluetooth low energy Find Me Profile.