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xArtx
Aug 6, 2012, 08:27 PM
Hi Guys,
Particularly the iPad...
The version with the cellular radio has a real hardware GPS,
The wifi only version does not.
Is there some easy way to tell whether or not the idevice has real GPS hardware?

It appears the wifi only version of iPad will not tell you the speed it is doing
(speed is constantly 0 no matter what the actual speed is).

Cheers, Art.



Duncan C
Aug 6, 2012, 08:44 PM
Hi Guys,
Particularly the iPad...
The version with the cellular radio has a real hardware GPS,
The wifi only version does not.
Is there some easy way to tell whether or not the idevice has real GPS hardware?

It appears the wifi only version of iPad will not tell you the speed it is doing
(speed is constantly 0 no matter what the actual speed is).

Cheers, Art.

You can add the gps key to your app's UIRequiredDeviceCapabilities array/dictionary in your app's plist. That will make the app require the GPS. Finding out if the device has a GPS at runtime is harder. I'll have to do some digging for that.

xArtx
Aug 7, 2012, 07:00 PM
You can add the gps key to your app's UIRequiredDeviceCapabilities array/dictionary in your app's plist. That will make the app require the GPS. Finding out if the device has a GPS at runtime is harder. I'll have to do some digging for that.

Hi,
I do want the app to run on all iPads, but want to ignore the speed reading
if the unit has no GPS.
I can think of a dodgy way.. if the location changes significantly, but the speed stays zero, the unit does not have GPS hardware... but I think there would be a better way..

Duncan C
Aug 7, 2012, 07:22 PM
Hi,
I do want the app to run on all iPads, but want to ignore the speed reading
if the unit has no GPS.
I can think of a dodgy way.. if the location changes significantly, but the speed stays zero, the unit does not have GPS hardware... but I think there would be a better way..

A slightly less "dodgy" way would be to check the vertical accuracy reading on location updates. If it is -1 (invalid) then the reading did not come from a GPS. You only get vertical location data from an actual GPS.

Richdmoore
Aug 7, 2012, 07:28 PM
Hi Guys,
Particularly the iPad...
The version with the cellular radio has a real hardware GPS,
The wifi only version does not.
Is there some easy way to tell whether or not the idevice has real GPS hardware?

It appears the wifi only version of iPad will not tell you the speed it is doing
(speed is constantly 0 no matter what the actual speed is).

Cheers, Art.

You may want to include a toggle or some other override method for those who have hardware like the iPad wifi, but use a 30 pin or bluetooth GPS (Dual xgps150, bad elf gps, Garmin GLO) for example.

Duncan C
Aug 7, 2012, 08:51 PM
You may want to include a toggle or some other override method for those who have hardware like the iPad wifi, but use a 30 pin or bluetooth GPS (Dual xgps150, bad elf gps, Garmin GLO) for example.

But the location manager won't work with an external GPS, will it?

Richdmoore
Aug 7, 2012, 10:11 PM
But the location manager won't work with an external GPS, will it?

All I know is that you have to use either a 30 pin or bluetooth receiver made for iOS devices. Once hooked up, it is just like using the native GPS on those devices that have it, and it adds GPS to those devices that don't have them. The GPS works with all apps, the apps don't know that an external GPS position is being used vs the internal system.

Links to some of the units:

http://bad-elf.com/products/be-gps-1000/
http://xgps150.dualav.com
https://buy.garmin.com/shop/shop.do?pID=109827
http://www.gns-gmbh.com/index.php?id=194&L=1

xArtx
Aug 8, 2012, 10:03 AM
I'm getting vertical accuracy 10m returned, and the unit has no GPS.

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Links to some of the units:

http://bad-elf.com/products/be-gps-1000/
http://xgps150.dualav.com
https://buy.garmin.com/shop/shop.do?pID=109827
http://www.gns-gmbh.com/index.php?id=194&L=1

Thanks, any better than the idevice GPS?
I've used it once to summit a 1300m mountain, and it was unreliable compared to a purpose built hiking GPS (regarding location).

Richdmoore
Aug 8, 2012, 12:03 PM
I'm getting vertical accuracy 10m returned, and the unit has no GPS.

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Thanks, any better than the idevice GPS?
I've used it once to summit a 1300m mountain, and it was unreliable compared to a purpose built hiking GPS (regarding location).

The external GPS units have WAAS to increase the accuracy, and work places that the internal units gps does not, such as a jet aircraft in flight above 18,000' (which is why I have one.)

My understanding is that they are also popular with boaters.

Only downside it that an external unit doesn't use the cell network to help with the initial position fix, so the initial position can take slightly longer than the built in GPS.

Duncan C
Aug 8, 2012, 01:16 PM
I'm getting vertical accuracy 10m returned, and the unit has no GPS.




Really? That's very odd. Which specific device, (e.g. second generation WiFi only iPad) and what OS version & subversion?

xArtx
Aug 9, 2012, 09:26 AM
Really? That's very odd. Which specific device, (e.g. second generation WiFi only iPad) and what OS version & subversion?

16Gb new ipad wifi only iOS 5.1.1, dev kit in the late 5s.

The vertical accuracy seems to settle on 10m, but I have seen it jump to 12 and back.
Don't know if this could be reliable though.