Location Detection Solution for ZigBee Wireless Sensor Network - CC2431 and Z-Stack - Texas Instruments

Texas Instruments introduced the System-on-Chip (SoC) solution with a hardware location finder engine targeting ZigBee/IEEE 802.15.4 wireless sensor networking applications. The CC2431 (Chipcon product line), supported by supported by TI's Z-Stack protocol stack,  targets applications such as inventory control, patient monitoring, security, remote controls, and commissioning networks.

Key features of the Location Engine:

• A blind node can use from three to eight reference nodes for the location estimation algorithm
• Location estimate with resolution of 0.5 meters
• Time to estimate node location less than 40 µs
• Location range 64 x 64 meters
• Location accuray of 3 meters or less
• Location estimation with minimum CPU usage and no esternal hardware or connections required

Chipcon CC2431 ZigBee with Location Engine SoC

This radio location feature is also suitable for active RFID applications such as asset tracking, inventory control, container/pallet tracking, and access-control systems.

Art George, TI, said:

Combined with the Z-Stack, the CC2431 provides the market's most competitive ZigBee solution and illustrates the innovation and market leadership of the Chipcon product line…

Customers will now be able to develop reliable and robust wireless networks, while reducing time-to-market and minimizing production costs…

The CC2431 combine the CC2420 RF transceiver core with an enhanced 8051 microcontroller, featuring up to 128 KB flash memory, 8 KB of RAM and many additional features. The CC2431 is pin to pin compatible with CC2430 and is identical to the CC2430 (128k version) in all aspects – the only difference is the addition of a radio location hardware core.

The CC2431 calculates the node's position based on the receive signal strength from RF Transceiver reference nodes with known locations and can then send the location information to a the user’s computer, mobile phone or PDA. This capability reduces network traffic and communication delays compared to centralized location detection systems. In typical applications, accuracy of 3-5 meters can be achieved.

TI's Z-Stack protocol software is designed to the ZigBee 2006 specification and supports multiple platforms, including the CC2431, CC2430 and CC2420+MSP430 platform. The Z-Stack has been awarded the ZigBee Alliance's golden unit status by the ZigBee test house TUV Rheinland and is used by thousands of ZigBee developers worldwide.

Features Summary of TI’s ZigBee with Location Engine SoC:

• Location Engine calculates the location of a node in a network
• High performance and low power 8051 microcontroller core.
• ZigBee® protocol stack (Z-Stack™) from Texas Instruments includes support for CC2431’s location engine.
• 2.4 GHz IEEE 802.15.4 compliant RF transceiver (industry leading CC2420 radio core.
• 128 KB in-system programmable flash
• 8 KB RAM, 4 KB with data retention in all power modes
• Powerful DMA functionality
• Excellent receiver sensitivity and robustness to interferers
• Very few external components
• Only a single crystal needed for mesh network systems
• Low current consumption (RX: 27mA, TX: 27mA, microcontroller running at 32 MHz)
• 0.3µA current consumption in power-down mode, where external interrupts can wake up the system
• Only 0.5µA current consumption in power-down mode, where external interrupts or the RTC can wake up the system
• Very fast transition times from low-power modes to active mode enables ultra low average power consumption in low duty-cycle systems
• CSMA/CA hardware support
• Digital RSSI / LQI support
• 128-bit AES security coprocessor
• ADC with up to eight inputs and configurable resolution
• Two powerful USARTs with support for several serial protocols.
• Hardware debug support
• Watchdog timer
• One IEEE 802.15.4 MAC Timer, one general 16-bit timer and two 8-bit timers
• RoHS compliant 7×7mm QLP48 package
• 21 general I/O pins, two with 20mA sink/source capability
• Powerful and flexible development tools available
• Wide supply voltage range (2.0V - 3.6V)
• Battery monitor and temperature sensor

TI also offers the CC2431ZDK ZigBee development kit to speed-up development cycle. The CC2431ZDK is designed to deliver the most powerful elements for ZigBee development with the location engine in the market today. The kit is based on the CC2431 System-on-Chip, which includes the core of the CC2420 transceiver, an 8051 controller, 128 kByte flash memory and lots of useful peripherals.

The CC2431ZDK ZigBee development kit includes:

• Z-Stack, TI’s ZigBee stack
• 2 CC2430EM Evaluation Modules
• 2 SmartRF04EB Evaluation Boards
• 5 CC2430DB Demonstration Boards
• 10 Battery Boards for use with the CC2431EMs
• 10 CC2431EM Evaluation Modules
• Antennas and cables
• IAR EW8051 C-compiler with C-SPY debugger (30+60 days evaluation license.)

The hardware includes the content of the CC2430ZDK and the CC2431DK. The dedicated CC2431 hardware can easily be used for testing the location engine in ZigBee networks. Totally the kit includes 7 CC2430 boards that can be used for reference nodes in a network and 10 CC2431 boards that are able to calculate their own position as well as act as reference nodes.

The hardware included in the kit contains necessary support to evaluate, demonstrate, prototype and develop software targeting various ZigBee applications with location capabilities. The SmartRF04 EB provides the user with functionality such as joystick, buttons, USB port, RS-232 port and an LCD display. This board also includes hardware support for programming CC2430EMs, CC2431EMs and custom made boards. The CC2430DB demonstration board will make it possible to implement true low power applications that can last on batteries for years.

The CC2431ZDK ZigBee development kit is supported by IAR Embedded Workbench for 8051, which is used with the MAC, the Z-Stack and location engine application examples. C-SPY Debugger is used as emulator interface. Both the IAR C/C++ Compiler and C-SPY Debugger are included in the development kit as 30-day evaluation licenses.

A flash programmer for CC2430 and CC2431 is included in the SmartRF Studio software package available from TI website.

Volume production of CC2431 is scheduled for 3Q this year. The device is available in QLP-48 package (7mm x 7mm) and is priced at $6.45 each in 1K qty.

Source:

• Location Finder for ZigBee Wireless Sensor Networking
• ZigBee/IEEE 802.15.4 solution with location estimation capability