David Samblas Martinez wrote: > Ok I will auto-answer to this question based on you > answer with more accuracy data > based on > http://www.eoss.org/pubs/nmeafaq.htm > NMEA 0183 sentences= up to 82 Ascii chars-->one > sentence per second-->82 bytes per second > so 60*60*24*82=7084800
It's (probably) better than that, as long as you're not in constant motion. If you sit in one place for an hour, you don't need to store 3600 NMEA sentences that say the same thing. It shouldn't be too hard to write an algorithm that can tell the difference between "moving" and "stationary", and store data accordingly. Depending on the degree of precision you desire, you can potentially reduce the storage requirements drastically. And if you're moving in an approximately constant speed and direction, you can throw away all the data points along any straight line segment, and only keep the beginning and the end. I believe that this is what Garmin devices do (based on the docs for my Garmin cycle computer). However, this all may be moot, because GPS sucks up no small amount of power. I don't know that the Freerunner will have the juice to run GPS all day long. My Garmin gets 10-11 hours out of an 800 mAh battery (it does some other bike-computer stuff, but that draws *very* little power, given that non-GPS cycle computers can run for months on a couple button batteries). The Freerunner has a 1200 mAh battery, and its also running a GSM modem, and doing other PDA-like stuff. Heck, if you're trying to store GPS data, you're going to have to have the processor awake the whole time, which is another drain. Hmm, then again, looking here: http://wiki.openmoko.org/wiki/Neo1973_GTA01_Power_Management It says: "This would imply that with the CPU constantly on in low power mode, GPS and GSM blipping on and off, and display off, the worst case power consumption is probably around 70mW, leading to a battery life of 2 days." So I guess we'll see when the hardware gets here... -- -------------------------------------- Dirk Bergstrom [EMAIL PROTECTED] http://otisbean.com/ _______________________________________________ OpenMoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
