OK, based on very limited testing, it looks like I was wrong. GPS on camera A. Turned on camera, then the GPS unit. Calibrated (calibration OK reported almost immediately, before hardly any camera rotation). Stepped outside; the blue light blinked in "search" mode for a couple of minutes before figuring out where I was. So, no advantage to being mounted continuously on a body with no battery change since the last time used. Turned off the GPS unit, moved it to body B. Turned everything on, again got almost immediate "calibration complete" message. The blinking "searching" light went out in about 5 seconds. So, no loss of memory within the GPS unit if turned off and if moved to a different body. So, my theory is discarded. Back to your regular programs.
stan On Sep 13, 2013, at 7:18 PM, Stan Halpin wrote: > 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 <[email protected]> wrote: >>> On Thu, Sep 12, 2013 at 8:14 PM, Rob Studdert <[email protected]> >>> 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 >>> [email protected] >>> 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 >> [email protected] >> 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 > [email protected] > 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 [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
