Location via WiFi on Mobile?

[Scott Rossi]

I'm still trying to fathom Location Services on mobile, if this helps
anyone.

Apparently under iOS 5.1.1 (using wifi), the locationChanged message is
not sent at all when querying location "loosely" (nor is any location data
provided by the sensor).  But location data is detected when
mobileStartTrackingSensor is started using "detailed" readings

There's a quirk in this however, in that location tracking will work as
expected for a bit after the sensor tracking is turned off and then
restarted using loose readings.  There seems to be some time threshold of
the sensor being available which has been hard to pin down (maybe
variable), and appears to be the cause of the inconsistent results I've
been getting.

Frustratingly, all works as expected under iOS 5.1 (loose or detailed).

So from what I can tell, if you need your mobile app to get location data
reliably across system versions, used detailed sensor tracking.  Until
somebody else figures this out better than I.  Or until the asteroid due
Feb 15 wipes out Earth's geolocation services.

Regards,

Scott Rossi
Creative Director
Tactile Media, UX Design




On 2/5/13 10:35 PM, "Scott Rossi" <scott at tactilemedia.com> wrote:

>Answering my own question...
>
>After messing around with this for several hours (and some gracious
>off-list suggestions from John Dixon), it seems that a delay is indeed
>necessary between first calling mobileStartTrackingSensor and actually
>trying to get the location.  I wound up essentially doing this:
>
>mobileStartTrackingSensor "location", false
>      wait 1000 millisecs with messages -- IMPORTANT
>get mobileSensorReading("location", false)
>
>
>
>It seems that AT LEAST a 1 second delay is required.  It may be that a
>longer delay may be necessary "out in the field".
>
>Boring testing details follow -- feel free to ignore...
>
>I was testing on 3 devices: an iPad 2, and iPhone 4, and an iPod touch,
>all via wifi -- and discovered an odd behavior.  The iPad and iPhone
>repeatedly failed at attempts to retrieve location, while the iPod worked
>consistently.  All were running the same block of code from the same LC
>stack.  For the life of me, I could not figure out what the difference
>was, until checking the iOS versions: the iPod was running an older
>system 
>version (all are using a flavor of iOS 5).  Perhaps Apple added
>additional 
>"goodness" to more recent versions of iOS, so location services take
>longer to start.  And I haven't even tested on iOS 6 yet.  I don't know
>how one would ever be able to track this down, much less troubleshoot it,
>without having access to multiple devices.
>
>Anyway, the lesson learned here: when in doubt, delay.
>
>Regards,
>
>Scott Rossi
>Creative Director
>Tactile Media, UX Design
>
>
>
>
>On 2/4/13 10:40 PM, "Scott Rossi" <scott at tactilemedia.com> wrote:
>
>>Hmm, maybe spoke too soon.  Still getting odd, inconsistent results.
>>
>>I thought maybe if mobileStartTrackingSensor was started using 'true'
>>(non-accurate sources) that mobileSensorReading should be used with
>>'false' (not detailed). But trying each combination of booleans I still
>>don't get a reliable result.
>>
>>This is weird.  On a few occasions, the expected values were answered,
>>but
>>most of the time, I either get empty or the boolean used with
>>mobileSensorReading in the answer dialog.
>>
>>Does it take time to start up location services?  Is it possible that the
>>device needs a few seconds of "warm up" time before it can return a
>>meaningful result?
>>
>>Regards,
>>
>>Scott Rossi
>>Creative Director
>>Tactile Media, UX Design
>>
>>
>>
>>
>>On 2/4/13 9:56 PM, "Scott Rossi" <scott at tactilemedia.com> wrote:
>>
>>>[ forehead slap ]
>>>
>>>Doh.  Thanks Jacque -- guess I wasn't reading the docs closely enough.
>>>
>>>Regards,
>>>
>>>Scott Rossi
>>>Creative Director
>>>Tactile Media, UX Design
>>>
>>>
>>>
>>>
>>>On 2/4/13 9:52 PM, "J. Landman Gay" <jacque at hyperactivesw.com> wrote:
>>>
>>>>On 2/4/13 11:43 PM, Scott Rossi wrote:
>>>>> Anyone know if the mobileSensorReading function works for "location"
>>>>>on
>>>>>iOS
>>>>> devices through WiFi?  I can't seem to get any data from the function
>>>>>when
>>>>> testing a simple stack on an iPad2 and iPod.
>>>>>
>>>>> Using this script:
>>>>>
>>>>>       get mobileSensorAvailable("location")
>>>>>
>>>>>        if it is false then
>>>>>
>>>>>           answer "Unable to use location."
>>>>>
>>>>>           exit mouseUp
>>>>>
>>>>>        end if
>>>>>
>>>>>        --
>>>>>
>>>>>        mobileStartTrackingSensor "location", true
>>>>>
>>>>>        put mobileSensorReading("location", true) into geoData
>>>>>
>>>>>        mobileStopTrackingSensor "location"
>>>>>
>>>>>        answer geoData
>>>>>
>>>>>
>>>>> Playing around with variations of this script, I either get "true" or
>>>>>empty
>>>>> in the geoData variable.  Am I missing something?
>>>>
>>>>It looks like the detailed location (what you get when you specify
>>>>"true" in the second param) will be an array, so after getting the
>>>>geoData you'd need to parse out something like geoData["latitude"] or
>>>>geoData["timestamp"].
>>>>
>>>>-- 
>>>>Jacqueline Landman Gay         |     jacque at hyperactivesw.com
>>>>HyperActive Software           |     http://www.hyperactivesw.com
>>>>
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>>>
>>>
>>>
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>>
>>
>>
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