>From my limited use of the O-GPS1, I suspect that the approximate current >location is stored in camera, enabling a faster "warm start" as long as the >O-GPS1 remains mounted. If you take it off the camera to change battery, to >use the flash, whatever, then you are starting cold. It may even remain stored >in the camera until the next time you use the O-GPS1, even if the unit is >dismounted and reinstalled, which works out if you haven't moved very far. But >I'll bet that if you move it to a different camera body, you are back to a >cold start. I'll dig mine out and play with it later.
stan On Sep 13, 2013, at 6:47 PM, Rob Studdert wrote: > I forgot about that :) I reset my phones "A-GPS XTRA" data and it did > take a lot longer to lock from a "cold start", probably not much > quicker than the O-GPS1. I don't have cell location turned on on my > phone but a couple of my apps that use GPS download the AGPS data on > start up if Internet services are available so I guess that's a > disadvantage with standalone non-networked devices like the O-GPS1. It > would be nice to know if the AGPS data is retained with the batteries > out or not, using rechargables I could tolerate leaving the thing with > a battery inside I guess. > > From http://www.pentax2u.com/webshaper/store/viewProd.asp?pkProductItem=108 > > "Pentax's O-GPS1 GPS unit draws power from one AAA-sized battery, and > is capable of a cold start in around 40 seconds, while a warm start > takes just 5 seconds. It can determine location information at one > second intervals, save GPS track information, and has a battery life > of around 5-7 hours from a rechargeable NiMH battery. Maximum battery > life is around 12 hours with a lithium disposable cell at around 23°C > / 73°F." > > I will attempt to measure the on and off state currents at some stage. > > Cheers, > > > > On 13 September 2013 22:51, Matthew Hunt <m...@pobox.com> wrote: >> On Thu, Sep 12, 2013 at 8:14 PM, Rob Studdert <distudio.p...@gmail.com> >> wrote: >> >>> When it works it seems pretty good but it does take an extraordinarily >>> long time to lock sometimes (noticeable when the phone takes seconds) >>> and it's really touch on batteries too. >> >> Getting a fast GPS lock depends on having up-to-date ephemeris data, >> which is broadcast by the satellites. A phone is on pretty much all >> the time, so it should always have up-to-date ephemeris data. (Also, a >> phone could "cheat" by getting ephemeris data from cell towers or the >> Internet; I'm not sure if they do that or not.) The O-GPS1 is probably >> used less frequently, so it's likely not to have recent ephemeris data >> at startup. It might also forget its ephemeris data when the batteries >> are removed. Getting an initial fix without ephemeris data can take a >> lot longer. >> >> -- >> PDML Pentax-Discuss Mail List >> PDML@pdml.net >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> to UNSUBSCRIBE from the PDML, please visit the link directly above and >> follow the directions. > > > > -- > Rob Studdert (Digital Image Studio) > Tel: +61-418-166-870 UTC +10 Hours > Gmail, eBay, Skype, Twitter, Facebook, Picasa: distudio > > -- > PDML Pentax-Discuss Mail List > PDML@pdml.net > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
