This is a story of a good product gone bad--namely my own global- positioning system terminal, which suffered an untimely death to serve as the subject for this teardown analysis.
Call it an excuse to upgrade.
GPS has been around for years, starting with government-driven development throughout the 1970s and 1980s. By the 1990s, the commercial application of GPS was in full swing, and companies like Trimble Navigation and Magellan began selling receivers to both public-sector customers and private-sector consumers.
Like any electronics-driven device, GPS receivers have undergone the cost reductions that the silicon technology juggernaut continues to deliver. Core GPS receiver chip sets are now available from a host of semiconductor vendors, with power consumption reduced to levels that allow GPS to be embedded in nearly any mobile product.
So what makes a relatively modern receiver tick? The story, as it turns out, is largely about the elements that surround the GPS devices, and the software and data platforms that come along for the ride. Receivers may have shrunk to a handful of components, but the quality of the user experience rests on the efficacy of tying longitude and latitude coordinates to real-world maps and consumer-friendly applications.
The Navman iCN510 dissected here is a standalone GPS receiver and navigation product, fit into a PDA form factor and sporting a 3.5-inch color touchscreen LCD. Running for several hours or more between charges on the 1,350-milliamp-hour, 3.7-volt lithium-ion battery, the iCN510 won me over with its go-wherever design.
Featuring an outstanding holster with suction-cup mount, the device moves (or used to move) freely among the cars in our family and even a motorcycle windscreen. I didn't have the scratch for a dedicated in-car navigation system, but the sub-$400 iCN510 did the trick with more flexibility than--and arguably equivalent functionality to--any OEM automotive GPS solution. Using the somewhat dated but good-enough set of mapping CDs included with the product, I was able to buy a 1-Gbyte Secure Digital memory card and preload details for virtually all of the United States. A quick reallocation of storage for any missing map data covers me in cases where something new is required.
The internal design spreads electronics across two printed-circuit assemblies--one for the GPS receiver and the other for all of the associated processing and user interface. As can be seen, the receiver board represents a small fraction of electronics content, supporting a two-chip solution from SiRF Technology Inc. that splits RF reception (GRF2i/LP) and digital processing (GSP2e/LP). A 512-kbyte nonvolatile memory from Silicon Storage Technology Inc. provides local code store to run the GPS engine.
Adding only a pair of clock oscillators, a surface acoustic-wave filter and a smattering of discrete components, the receiver itself is complete.
