Your Light Bulb Is Calling

RF interfaces permeate everything from appliances to light bulbs; even dumb devices can call for help.


By Pallab Chatterjee

The mobility that is best associated with “smart phone” functionality is making its way into most other electronic systems. At ISSCC and even the Strategies in Light conference, systems and products were being shown featuring standard RF interfaces.

The RF is being made available as standalone die for multi-die and 3D packaging, as well as in SoC IP blocks. The functions that were displayed were full radios in the 802.11, WiMax, 3G, Bluetooth, and in the 802.15 (Zigbee) space.

The availability of wireless access to remote systems, such as through the Internet or to local household/office environments, has changed modern SoC architectures. New systems embracing this functionally include medical devices, home automation (lighting, A/V, environment, security), smart appliances and fixtures, automotive, sensors and asset tracking. The standard SoC now being created incorporates the microcontroller(s), program store memory, power management, custom control logic, sensor interface (data converters) and now an RF interface block. On most of the systems, the RF block is replacing the video and standard wired communication block, and is closely integrated with the power management function to ensure the operational life, especially with battery-powered systems.

At Strategies in Light, which focused on new low power, high-brightness LED (light-emitting diode) lighting solutions, Marvell Semiconductor and NEC both displayed wireless control systems for lighting. In addition to dimmer systems that support LEDs in DALI applications (DALI is an international standard for ballast control), NEC was showing new modules based control systems that have a receive module in the lighting unit and a controller based board with RF that features a full software and GUI based control panel. This allows for full programming of lighting banks, color and intensity of LEDs, as well as light output, duty cycle and degradation of the units. It also provides for advance scheduling of maintenance on the lighting modules in industrial applications rather than having to do in-the-field response to a lighting head failure.

Marvell was showing off a control system that fits inside the base of a standard light bulb, which transforms an LED bulb into a smart system. It includes an RF interface – either Zigbee or Bluetooth for home automation application or 802.11 to interface to a home /office network. The company demonstrated the system using an iPhone as a controller, and it has a full SDK for application developers to create their own interface and feature set. With the iPhone users can remotely turn on/off and dim the device, as well as track hours of operation and power use. The same controller ICs can be used in combination systems that have motion sensors, temperature sensors and other function to supplement the lighting function, and send data through the RF channel.

At ISSCC a tutorial on RF integration into SOCs and design of Smart Sensor Systems led off the conference. Following the tutorials, papers were presented on a wireless 32-channel neural recoding SOC, a supply current modulated AFE based neural recording tag. The keynote from Bosch Electronics and TI both discussed the wireless interface to sensor devices and MEMS and the prevalence in current communication and automotive systems. The Emerging Medical Application session, was filled with telemetry based and wireless power based SOC applications.

The extension of this wireless integration is projects such as HP’s CeNSE (Central Nervous System for the Earth) project. CeNSE is a meta-project involving multiple HP Labs focused on enabling a planetary system of a trillion nanoscale sensors and actuators embedded in the environment and the networks to exchange their information among analysis engines, storage systems and end users. It is a system based on building nanoscale sensor nodes to wireless and photonic networks to storage and computation to data visualization, information theory and analysis. It is entering it first phase of delopyment in 2010.