Electronic Design

Remote Controls Go From IR To IF

An essential piece of our everyday technology is about to change. At its Technology Forum in June, Freescale Semiconductor announced its EC-net entertainment control platform, which will dispose of the typical infrared (IR) remote control that we all know and love and replace it with IEEE 802.14.4 technology (see the figure).

Despite more than 30 years of service and billions in daily use, the IR remote control has its limits, with an upper range of about 15 ft and a need for direct line of sight (LOS) and a ±15° cone of acceptance to operate. Today's growing TV screens and complex home entertainment systems with DVD players, PVRs, sound systems, set-top boxes, and other items—demand more flexibility.

Freescale's true point-to-point solution is based on the IEEE 802.15.4 wireless standard for personal-area networks (PANs) in the 2.4-GHz band, which is now widely adopted in home and building/industrial monitoring and control applications. Additionally, the standard is the basis for ZigBee wireless mesh networks.

By adding a networking layer to 802.15.4's media-access controller (MAC) and physical layers (PHYs), the result is a comprehensive platform that enables advanced control capabilities such as two-way communications between the controller and/or between the different devices being controlled. This opens up a whole new world of control options and features.

Current IR remotes are unidirectional. They're also proprietary designs, as each manufacturer has its own control protocol. Large memories are needed to store tables. In addition, the protocols call for multiple redundant transmissions to ensure that each command is received. This uses excessive power. Interference from plasma and LCD screens decreases reliability as well.

An RF remote has no LOS limitation, and the range is considerably longer. With RF, you get truly "remote" control. Furthermore, RF protocols can verify successful packet reception, eliminating the need for redundant transmissions. With bi-directional communications, a remote also can download program guides and other information for display on a remote LCD. And, device capabilities can be transmitted to the remote for automatic device configuration.

Freescale's EC-net control platform network is a stack built on the 802.15.4 PHY and MAC layers. Consumer electronics manufacturers can add an applications layer above that. The EC-net also can co-exist with a ZigBee stack, making the remote useful for controlling other home devices like lights and ceiling fans.

It features 65,535 (64k) potential commands, 16k public commands, 16k manufacturer-specific commands, and another 32k for internetworking commands and identifiers. Some commands may also have a payload. It additionally features device pairing via the remote. With such a flexible system, designers will have lots of opportunities for creative control scenarios.

Freescale is working with several leading consumer electronics manufacturers to drive the RF remote system to become a global industry standard that will be publicly available in 2008.

Freescale Semiconductor

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