Arduino + GPS + SD Card -> GPSLogger

Tonight I tested out a pretty good version of a GPS datalogger. As mentioned in my previous post Arduino Storage + GPS, I have these components:

• Arduino Uno Rev 3
• Dexter Industries GPS Shield
• Seeedstudio SD Card Shield
• Polaroid 512 MB SD Card, formatted DOS_FAT_16.
• Sistema Klip It 6.7-Ounce Container - similar to this user's idea: jeffbookspace.blogspot.com, but I cut a whole in the site for the plug and a whole in the top for the GPS (triple stack does not fit, and I've learned from a burnt out strobe box that you don't force electronics into slightly smaller containers than they need).
• Romoss Ph40-s 10400mah Portable Rechargeable Charger

It checks the GPS on a 1 second delay, and if there is a change in latitude or longitude, it plots a new datapoint to the CSV file. Here is the latest source code for the project: GPSLogger.ino

For some reason the first few datapoints were messed up, but then it was pretty stable. Still not sure if that is the SD card warming up or the GPS. I ran the cleaned output through this site, gpsvisualizer.com which has a nice csv to google map plot, and came up with this for a quick walk tonight. Some of the datapoints were up to 5m off, but on the whole the vector and the trail were pretty accurate.

From a coding perspective the trickiest parts were fiddling with the conversion of output from DDMMYY to YYYYMMDD, extending the float or char arrays to Strings for simple output, and the use of the F() function to properly Serial-ize the labels, a question I learned the answer to from stackoverflow.com.

There are only 300b left however, so I'm not sure what data I can log with the remainder.