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ZigBee network device delivers location information

From Texas Instruments’ Chipcon product line, the CC2431 is a lowpower ZigBee wireless-sensor device that includes a hardware-location engine. In applications such as asset and equipment tracking, inventory control, patient monitoring, remote controls, security and commissioning networks, the device calculates the position of a mobile sensor that is within a mesh network of fixed sensors. Its location engine uses RSSI (received-signal- strength indication) from multiple fixed node points to make its estimate. In typical applications, accuracy of 3 to 5m is possible, TI says. The device employs TI’s ZigBee protocol stack, Z-Stack. The CC2431 is a development of the company’s existing SoC (System-on-Chip) solution for low-power RF applications, the CC2430: like that chip, it combines the CC2420 RF transceiver core with an 8051 microcontroller, up to 128 kbytes flash memory, and 8 kbytes of RAM. It is sampling now, with volume production scheduled for the third quarter of 2007 and aprice of $6.45 (1000).

In a further low-power 2.4-GHz wireless announcement, TI has said that it will develop products for the PAN (personal area network) wireless standard Bluetooth ULP (ultra low power)—formerly known as Wibree. Wibree was conceived by Nokia and NordicSemiconductorasaverylow-power wireless standard for low-data-rate, short-rangeapplications such as humaninterfacedevices and bio sensors(Reference 1). Accordingto the Forum that the two companiesset up, Wibree deviceswould typically run for extendedperiods—years—from smallbatteries, with low duty cyclesof data transmission. Recently,the Wibree Forum mergedwith the Bluetooth SIG: theWibree name will disappearand the standard will becomeBluetooth ULP. Both partiesprofessed themselves delightedwith the move, Bluetoothgaining another new mode,and Nordic/Nokia buildingcredibility for the concept withwider recognition.

Nevertheless, the standard still lacked the support of other semiconductor manufacturers until the TI announcement, which increases the likelihood that it will gain wider acceptance. Building on its existing instruments. The Capricorn–A chip is a cost-reduced version of the company’s previous Capricorn chip and saves system cost by use of embedded DRAM. The chip carries a 64-bit RISC core, camera interface, hardware graphics engine, CAN-bus interface, and 4 Mbytes of e-DRAM. The core is the MIPS-based TX49/L4 64-bit CPU core, which operates at 120MHz. The graphics engine can deliver up to 32-bit RGBA colours. The graphics accelerators enhance the display output through several handling functions, offering high-quality anti-aliasing that ensures smooth display of changing graphics. A frame grabber capable of working with a wide variety of inputdata formats is available for the capture and processing of video images, supporting applications such as rear-view monitoring. —by Graham Prophet
Toshiba, www. toshiba-components.com. 2.4-GHz experience, TI is developing solutions for both types of ULP Bluetooth implementations: a single-mode implementation for watches, sensors and other small devices; and a dual-mode implementation for communication with both single-mode and traditional Bluetooth devicessuch as handsets.

• Texas Instruments, www.ti.com.
• Nordic Semiconductor, www.nordicsemi.com.
• Nokia, www.nokia.com.
• Bluetooth, www.bluetooth.org.

REFERENCES

Prophet, Graham, “Wibree— wireless PAN with long battery life,” EDNE, January 2007, pg 12, www.edneurope. com/wibreewireless panwithlongbatterylife+artic le+405+Europe.html.