If you don't need the complexity that ZigBee or Bluetooth offers, but wireless capability is still a design requirement, then check out Texas Instruments' eZ430-RF2500 (Fig. 1). This device combines TI's 16-MHz 16-bit MSP430F2274 microcontroller with Chipcon's CC2500 RF transceiver chip on a removable target board (Fig. 2).
This low-cost development tool is designed for low-cost, low-power, and low-speed sensor and control applications. The CC2500's packet handling support is limited to cyclic redundancy code (CRC) checking, which is more than adequate for many applications, as are the 64-byte FIFOs. This radio chip also has a range of configuration options, including different operating frequencies in the 2.4-GHz band.
Designers will need to trade off transfer rate with distance and power consumption. Typical operating ranges include 450 feet at 10 kbits/s to 300 feet at 250 kbits/s. The chip uses a serial peripheral interface (SPI), making it a nice match for most microcontrollers, including the MSP430.
LOW-COST DEVELOPMENT The MSP430 and CC2500 target board plug into the same USB-based debug platform as other eZ430 systems (see "$1 Arms And $20 Development Kits" at www.electronicdesign.com, ED Online 14133) that support target boards like QuickFilter's SavFIRe (see "Mid-Range Micro Kits" at ED Online 12991).
The target board also includes a pushbutton and a pair of status LEDs. The 18-pin header provides access to the MSP430's analog and digital peripheral interfaces. The target board can be powered from a USB stick, via an AAA battery pack, or via the 18-pin header.
The development kit includes IAR's Embedded Workbench Kickstart edition and the Eclipse-based Code Composer Essentials. An application note covers the SimpliciTI Network Protocol. Two target boards are included with the system.
Comparable microcontrollers and wireless chips have been available for years, but this combination conveniently delivers them at a new price point. For a hands-on review, see "eZ430 Goes Wireless" at ED Online 16532.
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