GPS Locator System

ProtoLink built the prototype of a satellite-assisted pet location device for a client needing to reduce intellectual property to practice during the patenting process.  The purpose of the device is to notify a pet owner whenever their pet wanders from a predetermined region.

ProtoLink performed a variety of services while transforming the client's idea into a working prototype, including:

• the identification and procurement of suitable hardware
• packaging design
• embedded software development

The resulting location device consists of a GPS receiver, a microprocessor board, and a two-way paging device.

The microprocessor and GPS boards communicate with one another over an RS232 channel using the NMEA 0183 Version 2.0 ASCII protocol, while the microprocessor and pager boards communicate over a second RS232 channel using the Communication Linking Protocol (CLP) native to the pager.

ProtoLink devised the distance computation algorithms used to check for boundary transgressions.  These algorithms account for uncertainties associated with the GPS system, including Selective Availability (SA) and Horizontal Position Error (HPE).  Whenever the pet transgresses the boundary, the device sends a page to the host identifying its location along with an indication that the pet has traveled out of the region.  The page format adheres to a protocol designed by ProtoLink for communication between the location device and a host system.  Additional messages include status request/response, boundary request/response, and get/set boundary properties.