As a summer project I designed a GPS logger device. An early prototype of the device was completed late July. Since then I’ve been taking it along on bike rides, walks, fishing trips, and much more.
The image on the left is a path recorded from my bicycle ride in Itasca State Park. The path starts from the headwaters of the Mississippi River and follows the wilderness drive & bike route to the visitor center. I also road from the visitors center to the headwaters but the GPS reception was blocked by the ice pack for my lunch.
The GPS logger takes data from a Linx GPS module and saves it to a SD/MMC card. The data is formated in a KML flie which can be opened with Google Earth or uploaded to Google Maps. The GPS module outputs NMEA sentences at a 1Hz rate. The GPS logger uses the GGA sentence for longitude, latitude, and altitude.
The GPS logger is powered off of a rechargeable 3.6V Lithium ion polymer battery. The battery is charged using a USB power supply and a lithium ion polymer charger integrated circuit.
The source code for the AVR microcontroller can be found on github under the name GPS-Wolf. The PCB board layout is also uploaded to github.