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Unlock universal remote's Wi-Fi secret code

Posted: 13 Jun 2008 ?? ?Print Version ?Bookmark and Share

Keywords:teardown? universal remote control? home-entertainment system? Wi-Fi?

The ARRU449 is a universal remote control with the twist of Wi-Fi connectivity to link the remote to online resources intended to ease setup and provide programming resources. (Click to view full image)

With the increasing number of home-entertainment appliances in living rooms, Acoustic Research launched the ARRU449 LCD-screen-based universal remote control to reduce the clutter of brand-specific controllers.

The MSRP $399 universal remote control comes with a twist of Wi-Fi connectivity to link the remote to online resources intended to ease setup and provide programming resources.

I didn't get a chance to try the ARRU449 before the teardown analysis, but I was sorely tempted!the seeming fungus of remote controls in my home entertainment system drives me mad. We've got a flat-panel TV, cable box, DVD/VHS and a couple of game boxes in the mix, but it remains a challenge to keep it all riding on rails. Suffice it to say the controller disarray remains, but my search for a solution goes on at a glacial pace.

The QVGA (320 x 240) LCD screen on the ARRU449 hints at special things. The screen provides the user interface to a range of features available by the unit's 802.11b/g connectivity. After linking to a home Wi-Fi network, the controller interacts with the click365 network from TVCompass Inc. to deliver location- and service-provider-specific TV listings and program descriptions, along with news, weather, sports, interactive offers and information services. The click365 network also provides updates to device codes and setup information, at least in its listed feature set on the busy-looking retail box.

Along with the claimed ability to manage a "virtually unlimited number of devices," the ARRU449 supports up to 255 user-specified activities. The activities can be thought of as programmable shortcut macros to combine steps such as Turn on TV, Turn on Cable, Go to CNN, Volume to 5, etc.!appealing, at least in theory. The Wi-Fi universal remote control also has a built-in code library and automatic brand search to smooth setup, and learning functionality helps in cases of unlisted codes.

Complex internals
The 2.2-inch TFT QVGA display is one of the more expensive components, though it's surprisingly inexpensive these days, at $15 or less. The active-matrix display comes from Vista Point Technologies, a spinout from Flextronics' components division, which bought International Display Works.

The circuit boards inside the somewhat oversized remote begin to tell the story of what it takes to build a remote control on steroids. Whereas traditional remotes usually use a single controller chip ASIC on a cheap carbon-overprint phenolic circuit board, the ARRU449 has far more-complex internals. The larger of two multilayer PCBs hosts most of the controller electronics, while a second plug-in daughtercard is used for the Wi-Fi solution.

Starting on the larger main board, a Samsung S3C2410 ARM920T 16/32bit RISC microprocessor hosts peripherals such as LCD controller, NAND flash boot loader, UARTs, timers, real-time clock, eight-channel/10bit ADC, touchscreen interface (unused here), I?C interface and USB. Implemented in 0.18mm CMOS, the big lifter is a fully static design targeted at cost- and power-sensitive applications. Two memories support the Samsung microprocessor, the first a Samsung 64Mbyte mobile SDRAM (K4M511633C) and the other a DiskOnChip NAND device from SanDisk's M-Systems (MD4832-d512).

The ARRU449 is powered by a rechargeable Li-Ion twin-AA cell battery pack. Given our household's lazy tendencies, I have to wonder how often the power-hungry microprocessor and Wi-Fi-enabled design would be found low on juice for lack of discipline in recradling the remote.

Primary power conversion and battery charge management are handled by a Linear Technology LTC3455 dual DC/DC converter and Li-Ion battery charger. An XC9116 step-up converter from Torex drives the four white LEDs for display backlight.

The remote communicates to target devices by way of conventional infrared control, and the ARRU449 uses a second, smaller, dedicated microprocessor from Zilog with its Z8F0811, whose own peripheral set includes an IrDA encoder/decoder.

Audio support comes from National Semiconductor's LM4864 300mW audio power amplifier to drive the internal speaker, while the headphone jack gets driven by a LM4921 DAC and amplifier combo chip, also from National. The DAC output is used as the source for the LM4864.

Wi-Fi boost
Wi-Fi is, of course, a central feature in this design, and Acoustic Research has taken advantage of the growing crop of single-chip solutions, using the Broadcom BCM4318E, which reduces radio, MAC and baseband processor to a single monolithic silicon CMOS device. The only additional components on the daughtercard-based Wi-Fi solution are a Skyworks SKY65206 Wi-Fi front-end module combining an InGaP amplifier and Tx/Rx switch, and an Atmel AT93C66A 512byte EEPROM. A pair of ceramic chip antennas top off the diversity air interface.

The use of a daughtercard for Wi-Fi suggests a possible multisourcing strategy!or at least a path to future upgrades. Flexibility to adapt the design to 802.11a/g may be an additional consideration in the partitioning, but in any case, a pair of coax cables and a board-to-board connecter are used to wire in the separate Wi-Fi assembly.

While I was a bit shocked at the suggested $400 retail price, street prices closer to $200 were the reality when I purchased. Acoustic Research has followed the age-old marketing plan of using an inflated MSRP, which shows up as half price on the street, to soothe sticker shock while retaining a handsome profit.

As I said, I never did get around to trying out the ARRU449. A 50+ page manual and seemingly challenging network setup left me thinking that the very objective of the product!to make entertainment control easy for all!was thwarted by a new set of complexities. When the solution to a problem seems as daunting as the problem itself, I tend to give up, and I'm probably not alone.

- David Carey
President, Portelligent

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