Pre-testing a "no data" situation

[Derring Do]

Will,

I've read your old post, and the new wiki on using GPSL w/o a data plan, but would like to take it for a test drive, as you recommend. Any hints for those of us fairly clueless on how to do that?

I'm still struggling to figure out how to go to Canada and turn off the 3G ability, yet leave on wifi. Somehow I doubt AT&T is going to be uniquely helpful with that information, either. Last thing I need is an expensive phone bill after this big trip.

Thanks as always for the help. As we found on the last 2 trips, I'm REALLY looking forward to sharing spikes, we kept forgetting randomly, and having to email and re-enter missed ones.

[Derring Do]

Update: Turned on airplane mode, wifi is working, went outside and tried to create new spike. Found me within about half a mile, but didn't improve even with several iterations. I'm clearly challenged trying to sort this out, so assistance very much appreciated. I seriously don't want some huge data bill later this summer from this trip.

[divzero]

Hey Erika,

Sorry for the delay, taking a break at the moment for a few days.

I updated the wiki with some testing advice: http://wiki.gpslog.cc/page/No_Data#Testing_this_Feature

When you travel, you generally cannot even use data unless you enable "Data Roaming" from your settings. So no risk of excess charges (just make sure Data Roaming is in fact disabled!). Data Roaming is normally incredibly expensive.

Airplane mode will completely disable the GPS antenna so you can't use it with GPS Log! That's why there is a message when GPS Log starts in this mode. Alas I cannot actually query the iPhone SDK to see if this mode is enabled, so I can't customise the error message to something more specific.

Best thing you can do to test is eject the SIM card. See the wiki for more info

Hope it works for you. Let me know how you go.

Cheers,
Will

[Derring Do]

Will, getting closer to the travel date, and had another ques. Sorry, haven't tried all of this before.

Airplane mode will work in a wifi situation, to enable me to send email and upload photos to MobileMe or wherever... pulling the SIM will let me use GPS Log.

Can I still use a wifi if the SIM is out? Should one pull the SIM as soon as you leave the country of origin? Sorry, definitely not clear on the capability, and even searching various places this must be too basic for people to answer.

One final ques. If I don't have data on, and take photos, do they still contain geotag data? Just in case someone I know eventually adds the ability to spike via a phot0graph?

Definitely still not clear on how I should be doing the little I plan on doing. Thanks as always for your help.

[divzero]

Here's some info that might help

NB. I have to state that this info is just from my own experiences, you should double check with your carrier if you are concerned about charges

Data Roaming
When you roam, by default "Data Roaming" is OFF. Don't turn it on, as it's hideously expensive. But if you leave it safely off, you should be fine! Of course, if your phone rings and you answer it, you will pay.

So don't worry too much from a data point of view, just don't turn on Data Roaming. If you don't want to pay for calls, don't answer your phone or make calls. Personally I never use Data Roaming, and only make calls for an emergency (or when trying to meet up with someone!).

Airplane Mode
Airplane Mode + Wifi, turns your iPhone into an iPod Touch. The GPS hardware will not work (just like an iPod touch which has none). This is a useful operating mode, but NOT useful at all with GPS Log

Testing before you go
The SIM card removal was the old way I recommended to test how GPS Log can operate in a data-less environment. Now there is a better way (in iOS 4). Settings -> General -> Network, turn 'Cellular Data' OFF. Then you can try GPS Log out in such an environment without removing the SIM. Your choice if you yank the SIM card when you travel…


No SIM
You can definitely use Wifi without a SIM card.

Photo GeoTagging

Photos probably won't get geotagged by the iPhone's Camera App without a data plan. This is because it takes longer to get a fix, and probably won't have a location in the time it takes you to press the shutter.

You *can* however do this in GPS Log. Because GPS Log actually tells you when you get a fix. In Advanced Settings (http://wiki.gpslog.cc/page/Advanced_Settings#Photos) you can enable "Also save a full-sized copy to the App directory" then download the photos via FTP. You can do this instead of, or as well as saving to the iPhone camera roll (doing both adds to the saving time). Photos you share to Flickr, or by Mail, etc will have the correct Meta Data.


Note
Getting the first location fix in a new location can take some time. Just be patient, put it on a table or even in your pocket and leave it running Use the 'Lock' feature in GPS Log to prevent the iPhone going to sleep.

Hope this helps

Enjoy your trip.

Will

[Derring Do]

Super information, Will, thanks so much for taking the time. I'm really hoping to be able to enjoy bits of the phone, we didn't have them the last time we really traveled.