GPS/Bluetooth Solution Makes Location And Navigation Apps A Snap

Consumers on-the-go demand global positioning system (GPS) functionality in multiple products. However, getting GPS into portable and wireless devices can be a tricky process. RF Micro Devices' RF8900 helps overcome the hassle by combining a GPS solution with a wireless interface.

The three-chip set supports GPS access in PCs, laptops, PDAs, automotive telematics, and cell phones through a Bluetooth radio. It's well-suited for "puck-style" devices that provide location information wirelessly. Available in a complete reference design, the chips include the GPS receiver front end, a GPS receiver baseband ASIC, and a single-chip Bluetooth transceiver.

The receiver uses a surface-acoustic-wave filter on the front end with a ceramic patch antenna and an external crystal. The GPS radio, a single-conversion type, features a low IF filter. The receiver sends the demodulated data to the baseband ASIC, which then communicates with the Bluetooth transceiver via a standard UART serial interface.

The Bluetooth chip's ARM processor performs the calculations required by the receiver chips. The processor also handles the Bluetooth stack and other related processing. The Bluetooth antenna resides on the reference design board. Transmission range is approximately 10 meters.

The RF8900's ­155-dBm sensitivity lets the receiver see satellite signals almost anywhere, including light indoor environments and even outdoors around trees, tall buildings, or mountains. The receiver provides the standard L1 and Coarse Acquisition code outputs. Position accuracy is better than five meters.

Data for position (latitude and longitude and altitude), time, and velocity is supplied to the Bluetooth radio. The transceiver complies with the 1.2 version of the Bluetooth special interest group specification. Input power measures 5 V at 100 mA. Also, outputs are provided for LEDs to indicate power on, GPS receive, and Bluetooth transmit.

Shipping now, the reference design includes all software, filtering, memory, reference frequencies, and antennas. Contact RF Micro Devices for pricing.