News

Your car keys can call your phone. No charge.

Motorola has anticipated the ratification of ZigBee - wireless networking that works like a slow, low-power Bluetooth - with a device that stops you losing your keys.

The company isn't the only outfit to jump the gun. ZigBee won't be ratified till nearly Autumn; but Atmel has also announced a product using the technology - not a consumer gimmick, but a building block for other builders of consumer gimmicks.

The Motorola toy is a concept demonstration only, and the company hasn't yet decided whether to turn it into production. The way it works is that you attach a ZigBee device to anything you don't want to lose, and (if you have a ZigBee phone) whenever it goes out of range, your phone screams at you.

It may be a good idea; but it depends heavily on having a lot of wireless devices around, according to this VNUNet report. Probably, it's not worth trying to turn into a product even next year - unless Motorola unexpectedly floods the market with ZigBee phones. There won't be any devices to talk to.

Atmel's Z-Link ZigBee chipset "will be available in May 2004 and will be priced at $6.75 in quantities of 100,000 for the radio, FFD controller and 802.15.4 and ZigBee protocol stacks," says the company in its press release. The AT86ZL3201 Z-Link controller will be available in 64-lead TQFP and 64-ball LFBGA packages. The AT86RF210 Z-Link 868MHz/902-928MHz 802.15.4 transceiver will be available in a 48-pin QFN package. Development boards will be available in June 2004.

The key difference between Bluetooth and Zigbee is battery life. Zigbee consumption is to Bluetooth what Bluetooth is to WiFi. Atmel is aiming to provide equipment that stays constantly in touch by switching itself off most of the time - aiming for a two-year battery life in typical industrial applications.

With 14.5 mA receive current and 4 mW (6 dBm) transmit current at 1.8 volts, Atmel's Z-Link transceiver consumes 25% less current in receive mode than competing 900 MHz 802.15.4 radios. The Z-Link radio's 1.8V power supply extends battery life beyond that which can be expected from 802.15.4 radios with 2.0V or higher power supplies. Power consumption in sleep mode is 1 uA.

Like Bluetooth and WiFi, ZigBee uses the universal "microwave oven" spectrum around 2.4 GHz and like 802.11b it uses direct sequence spread spectrum (DSSS) wireless. It's still unknown how it will co-exist with other 2.4GHz devices.