Eliminating Traditional AV Fascia Controls Using RF
The compact Canton RF remote (product code: RF-IR 1) with its own LCD (liquid crystal display) allows all traditional AV (audio-visual) fascia controls and status info to be eliminated. This appeals to modern ‘lifestyle' consumers that want a superior home theater experience, but without the cumbersome traditional AV system comprising five or more separate speakers connected to a dedicated AV amplifier, DVD player and video screen, all housed on a large space consuming rack that can dominate a room.
Instead, the Canton DM 1 and DM 2 offer users the same functionality as traditional systems but with amplification control electronics and at least three speakers eliminated. The Canton DM 1 and DM 2 are active (i.e. have their own amplification), 2.1-channel music and home theater systems that create a high quality (Dolby Digital, DTS and Pro Logic II) surround sound field normally associated with 5.1 systems (5 = left, right, centre dialogue and rear right, rear left speaker channels, 1 = subwoofer low bass frequency-only speaker channel).
"Fascia front panels aren't the most convenient location for control functions or status displays anymore," explains Frank Goebl, Head of R&D at Canton. "They're just located too far away from where the user actually needs and wants them – which is basically in the palm of their hand. That's why in our DM 1 and DM 2 products users can now see and control everything on the 12-button remote that they would have previously accessed from the front of their DVD player and AV amplifier."
In addition, to avoid the system's philosophy being compromised by the traditional remote controls of other vendor's products used with it, the Canton RF remote also includes a standard, self-learning universal Infra-Red (IR) transmitter to control up to six other conventional AV products such as TV/video screens and DVD players.
The DM 1 features a single 200-watt ‘psychoacoustic' virtual 5-channel horizontal main speaker cabinet (see "About Psychoacoustics" below for more information) and subwoofer. The DM 2 uses two separate 100-watt left and right channel ‘cube' speakers and the same subwoofer. For both product variants, the 150-watt subwoofer houses all the control, audio processing and digital power amplification electronics.
During operation, a pair of Nordic Semiconductor nRF905 433/868/915-MHz ISM band transceivers located in the remote and subwoofer head unit wirelessly relay status information and user control requests. (The specific band employed depends on country of use, ISM refers to the license-free Industrial, Scientific and Medical frequency portion of the available radio frequency spectrum.)
The Nordic Semiconductor nRF905 transceivers are ultra-low power devices designed to spend long periods in sleep mode consuming just 2.5 µA while the remote is not in use. Even in use, the devices consume just 9 mA in transmit (TX) mode (at -10 dBm output power) and 12.5 mA in receive (RX) mode. Due to these industry-leading ultra-low power characteristics, the standard 3 AAA alkaline batteries in the Canton RF-IR 1 remote control will last up to 7 months under typical domestic operating conditions. The nRF905 consumes just 15 percent of the overall power budget in the remote control, the rest being used by the LCD display and universal IR transmitter.
Interference immunity is assured by the nRF905's Address Match function. This function ensures that the transceiver controlling the IR transmitter only responds to a uniquely paired transceiver in the RF remote control. Pairing is achieved by assigning a unique address to the transceivers in the RF remote control and IR transmitter. Once paired the system cannot be upset by RF remote control devices in close proximity (for example, the neighboring house). Additional immunity is built in by allowing the user to change the frequency of the RF remote control to any of five channels from its keyboard should interference become a problem.
"We did look at a number of proprietary solutions, but selected Nordic because of the quality of technical support, transceiver on-air data rate, and ultra-low power consumption," adds Goebl. "In addition, Nordic made the EMC certification processes a formality rather than a development problem."
"Nordic sees a big future for RF remote controls based on their inherent advantages of non line-of-sight operation, long through-obstacle or wall range, and bidirectional capabilities enabling the support of advanced status and control feedback features," summarizes Geir Langeland, Nordic Semiconductor's Director of Sales & Marketing. "Canton is a progressive company that shares our vision and is one of the first to design an RF remote control maximizing the advantages of our ultra-low power RF transceivers. We are pleased to partner with such an innovative and world-renowned audio company."
SOURCE: Nordic Semiconductor ASA