Thursday, February 28, 2013

Where am I .... all the time

Okay lets start by clearly stating the futility of position, every defintion of position requires a reference frame. It would be pretty messy to define where I am relative to the centre of our galaxy at all times, the super-massive blackhole makes measuring time there pretty messy as well. I could define my position better in ECEF or ENU or in most cases Platte Carre. I set out to build a project which could define where I am at all times for the posterity and essentially keep a track of my spime. My spime is the only thing I have absolute natural rights to, everything else can be taken away and be subject to argument with sufficient legal juggling. Come to think of it even the personal spime is not inviolate, meh reading to much Hannu Rajaniemi. Android My Tracks is pretty good, but a phone sometimes feels like too many eggs in one basket, I don't want to leave it lying around in the car dash gathering sunlight.

The project is mainly based on a Seeeduino stalker board with a convenient Bee socket. I plugged the UBlox Neo-6M based GPS Bee there. Data logs go to a 2GB SD card and Lipo power is backed by a 1w solar cell. The GPS constantly spits out NMEA strings which get logged to the SD card as long as power and space is available. A log with 2 days worth of data took up 45Mb, so I can hold about 3 months of data. Unfortunately the 2000mAh battery died after 2 days of continous use, with some solar recharge while in use. Since the battery death, in order to prevent melt down in harsh sunlight and continuous use, I have added a USB charger option as a stop gap. This should hold the fort till I plug in the quartz/heat powered charger for use while hiking and the mini windmill for use while wind surfing. Eventually the SD card will blow off into star dust after I have had my fun and extracted and time and location of said fun, but hey SD cards are more expensive per-ounce than gold.

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