Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Can a Tablet get GPS location from WIFI hotspot?

Discussion in 'Pro/Adv Discussion' started by Vitruvius, Aug 10, 2016.

  1. Vitruvius

    Joined:
    Oct 27, 2015
    Messages:
    4
    Likes Received:
    0
    Can someone confirm please - I ordered a tablet without GPS or cell. I have an iPhone 5s with data. When I connect the tablet to the iPhone over WIFI hotspot, will the tablet get a GPS location? I have unlimited data (work phone) so I can stream maps but not sure it eh tablet will get the GPS from the phone. Thanks.
    Note I added thin copper shielding behind the tablet and keep the iPhone in my front pocket to seperate the WIFI signals and works good. Just that my Samsung Galaxy S2 is really laggy and needed a more powerful tablet.
     
  2. fastfed

    Joined:
    Jul 5, 2016
    Messages:
    544
    Likes Received:
    161
    no, you won't get "gps" location you're get "accurate location" within 100 or so feet maybe more.

    what tablet did you get?
     
  3. Meta4

    Meta4 Moderator
    Staff Member

    Joined:
    Jan 8, 2014
    Messages:
    7,729
    Likes Received:
    3,450
    The tablet may get a rough location from the wifi network if it is in wifi range but it won't get a GPS location.
    Your Phantom has a perfectly good GPS which is all it needs for flight.
    You only need GPS in the tablet for follow-me and resetting the home point to the controller location (used when you are moving a lot such as flying from a moving car or boat)
     
    flyNfrank likes this.
  4. GadgetGuy

    Joined:
    Jun 18, 2015
    Messages:
    4,452
    Likes Received:
    1,294
    You can also buy an external BT GPS ($100+, depending upon features) to pair with any tablet, and Follow Me and manually resetting the Home Point to the tablet/RC location will both use it, even if no GPS is natively available on the tablet.
     
  5. matti

    Joined:
    Mar 15, 2016
    Messages:
    400
    Likes Received:
    62
    Tethering your phone to a wifi only iPad does not share the phone's GPS.

    I bought a cellular iPad so I have a possibility for follow me mode or setting the home point to the RC instead of the AC. ...but I have never really used those features... So a non-GPS tablet is usually just fine with the Phantom. If you really need those features, then connect an external GPS device to the iPad (I have heard about brands like Bad Elf, Dual and the Garmin GLO).

    I often tether the phone to the tablet to update the DJI GO or Litchi maps via wifi.
     
  6. flyNfrank

    Joined:
    Feb 1, 2014
    Messages:
    4,216
    Likes Received:
    912
    Location:
    Indy, USA
    In other words Vitruvius, you DO NOT necessarily need gps in your device.

    With your new tablet you can walk out to the middle of a field and once the app displays the green P-gps box on the screen you are safe and ready for launch. You then fly whatever distance away and select RTH the aircraft will return to the original launch point.
     
  7. Wolfiesden

    Joined:
    Jan 12, 2016
    Messages:
    1,187
    Likes Received:
    400
    Location:
    Milwaukee, WI, Ft Walton Beach, FL
    True, however any function that needs to know the location of the RC (you), will not work. Or at best will not work correctly nor accurately.

    You also won't know accurate bearing and distance from YOU to the bird. From Home, yes, but from you no.

    Also dynamic home point will also be incorrect or non-functional so situations where you are moving (boat, car, etc), you will not know where YOU are on the map and that RTH may well drop your phantom in the water where your boat WAS but is not now.

    If none of that applies, then fly.

    With the price of tablets with GPS now, I just see it senseless to not own one with a GPS receiver. Even an apple fanboy can own an android tablet and tether it to his apple device's WiFi. From what I understand no Apple device without data has a GPS (at least none that I have heard of). On the other side, most Android devices have GPS, even without data plan. You can pick up a suitable Android tablet in the sub $200 range with GPS and dedicate it to your Phantom and have the best of both worlds, live in your Apple realm for your phone and data, and have a cheap tablet with GPS and not have to pay any data connection fees.
     
  8. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,530
    Likes Received:
    1,478
    Location:
    Sacramento CA
    This is not entirely true. Yes it's definitely true that most Android devices have GPS natively enabled, but it's not at all true that iPads need a data plan to get GPS.

    If you choose an iPad and want to use the optional features that require having GPS at the RC location, you'll need one of two things:
    1. A cellular version iPad. The cellular versions have GPS, even without a data plan. The WIFI only versions do not have GPS. It's that simple. No data plan is required nor has a data plan ever been required to get GPS data on a cellular iPad. Just having the cellular version is enough. If you ever read here that a data plan is required to get GPS with a cellular iPad, just ignore it and know that is not correct.
    2. An external GPS device as @GadgetGuy noted above. The most often mentioned here are from Bad Elf, Dual, and Garmin. Many people, myself included, use an external device in the rare times that we need to use any of the optional features that require GPS at the RC. Note: Buying the external GPS device one time means that you don't then need to buy the cellular iPad version each time you upgrade your iPad. You spend that money once. The cost of a WIFI only iPad + External GPS roughly equals the cost of a cellular iPad.

    Note again that I am only talking above about GPS and the optional GPS at RC features. I'm not talking above about internet access in the field or about the standard features that use the AC's own GPS.

    Internet access in the field (for example - to use optional maps or for GEO) is a different but important topic. Anyone considering a device for flying in a GEO enabled country who plans to use GEO enabled software should also consider if they want internet access in the field (via tethering or directly) for ease of use when unlocking zones. Zones can be unlocked in advance of course, but as part of your decision making process, consider if you want to do that in advance or do it in the field. Same for the optional maps - ease of access should be considered if you choose to use maps. You can cache them in advance, but do you want to do that or have them available directly from the internet while in the field?

    Just a few things to think about when making a decision about devices. Your choices will help you determine if you would prefer a cellular enabled tablet or not - be it Android or Apple - and if you prefer to have a data plan or not.

    Cheers and good luck!
     
    #8 Oso, Aug 11, 2016
    Last edited: Aug 11, 2016
    JoBe and GadgetGuy like this.
  9. Wolfiesden

    Joined:
    Jan 12, 2016
    Messages:
    1,187
    Likes Received:
    400
    Location:
    Milwaukee, WI, Ft Walton Beach, FL
    Yea @Oso, thats kinda what I meant but worded it wrong but you are very correct. What I meant, and that you correctly pointed out, is that Apple devices that are non-cellular generally have no GPS hardware. Poorly worded on my first post, sorry. A cellular version of an Apple device that does have GPS hardware does not need an actual cellular connection or data plan to use the GPS hardware. But it must have the hardware. And to get the hardware, you must buy a cellular version, activated or not.

    So from what I see you can get a WiFi only ipad (suitable for the phantom) for ~$130-$220 range depending on model and age. Then you go and buy a $100 GPS dongle for it. Why not just go buy a WiFi only Android for $150-$200 that has GPS and call it a day? Less screwing around and you can put it in airplane mode and still have GPS. Its less battery drain (no BT radio) and fewer things that can go wrong in flight to distract you.

    Yes, I too was not referring to needing internet access during flight which you don't. If you have cached the maps ahead of time, no need for it in the field. And even without cached maps, with GPS hardware you have a relative bearing and distance from you to the bird, just not what terrain you are flying over. However I too tether my tablet to my phone (both android in my case) when I need it. For example to sync Litchi hub missions or to cache maps on a spur of the moment flight I hadn't planned ahead for (driving along and see a "ooh thats a cool area" moment). I also need internet for Litchi's leash mode (where it follows another device) because it needs the internet connection to relay the GPS coordinates of the leash device back to the RC to then control the bird's location relative to that.

    Is GPS absolutely needed? No. But its a very valuable asset. Can you get it with a BT dongle? Yes. But it adds another device to maintain (batteries, etc) and further complicates your field hardware in addition to adding another failure point and will restrict your ability to turn on airplane mode.

    I try to take the path that has the least screwing around and the fewest failure points. I chose to get a Shield K1. Sub $200. Has GPS. Has fast CPU and graphics and screen recording, yadda yadda. Has way more than I will ever need for a phantom. Stick a sun shield on it and go fly is about the only setup I need to do in the field.
     
  10. bluer101

    Joined:
    Dec 1, 2015
    Messages:
    149
    Likes Received:
    51
    I use my wifi only iPad Air 2 with my iPhone 6+ hotspot. I use the hotspot until I get home point set and my map loaded. Then turn on airplane mode for the iPad. Works perfectly.
     
  11. flyNfrank

    Joined:
    Feb 1, 2014
    Messages:
    4,216
    Likes Received:
    912
    Location:
    Indy, USA
    Good to see you guy lay out the details on why it's beneficial for gps. I just let the OP know it wasn't a deal breaker that he could get by without gps. My opinion is he should cancel the order and hook up with a gps unit.
     
  12. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,530
    Likes Received:
    1,478
    Location:
    Sacramento CA
    Sure, that certainly works for maps and it's a common use case. However, the tethering from your phone does not send GPS data to your wifi only Air 2. Your initial home point is set with the GPS in the AC itself. You probably knew this already. I'm just clarifying for any future readers who may not yet understand the basics. Cheers!
     
    JoBe and GadgetGuy like this.
  13. GadgetGuy

    Joined:
    Jun 18, 2015
    Messages:
    4,452
    Likes Received:
    1,294
    The initial setting of the Home Point is always based upon the GPS in the aircraft at launch. The assumption throughout the flight of the telemetry is that the RC is still at that location. Should that change, and you wish to change the Home Point, a GPS that the tablet can use is required. The tablet then relays its GPS location data to the RC, which assumes that the tablet and the RC are in the same location. An Inspire RC already has GPS built into the RC, so it needs no tablet GPS, or external BT GPS, connected to a tablet without GPS. It also comes with a built in HDMI out. So an Inspire remote, with any tablet, is yet another option, to keep things really simple.
     
    JoBe likes this.
  14. Oso

    Oso

    Joined:
    May 19, 2015
    Messages:
    2,530
    Likes Received:
    1,478
    Location:
    Sacramento CA
    Excellent reminder. I always forget to mention the Inspire RC.
     
  15. GadgetGuy

    Joined:
    Jun 18, 2015
    Messages:
    4,452
    Likes Received:
    1,294
    It's also substantially more powerful, and might not even need any transmitter mod to get the desired control range. :cool:
     
  16. skipilot1

    Joined:
    Apr 14, 2016
    Messages:
    109
    Likes Received:
    24
    If you have a wi-fi connection, such as a hotspot connection on your phone, doesn't the map still show where you are? While this may not help RTH, as long as you have a connection with the quad, you should still be able to fly it back to your location based on the map.
     
  17. impilot51

    Joined:
    Dec 3, 2015
    Messages:
    405
    Likes Received:
    147
    It shows where the aircraft is, as well as previous flight path. But if ou have moved, it does not show your current location.


    Sent from my iPad using PhantomPilots mobile app
     
  18. GadgetGuy

    Joined:
    Jun 18, 2015
    Messages:
    4,452
    Likes Received:
    1,294
    You might be able to switch to another map app that uses your wifi location, if you have no cell reception to tether to, but DJI GO only uses the aircraft launch location until you can reset the Home Point properly. However, the telemetry of which direction the aircraft is facing relative to your current location might still be accurate. Not sure about that. Certainly, you can try rotating until the signal is strongest and pull back on the stick until it comes into view. However, you need a very good grasp of your location on the map, if you are going to move away from the Home Point, and have no means to reset it. Use VLOS only in those situations, and you should be fine! That's for following a moving boat or car containing you and the RC. Also be sure to turn Smart Go Home to OFF, or you will regret it! :eek:
     
  19. Wolfiesden

    Joined:
    Jan 12, 2016
    Messages:
    1,187
    Likes Received:
    400
    Location:
    Milwaukee, WI, Ft Walton Beach, FL
    Yes. And no.

    WiFi location is very very inaccurate to say the least. IF the WiFi has location data in the first place.

    The "Home" location, in therms of the Phantom, is initially set using the GPS coordinates received by the Phantom's own GPS receiver. It is not the GPS received by the tablet (assuming tablet has GPS).

    RTH will attempt to return to that "home" position unless the "home" position is updated in some way.

    The "home" position is NOT your position. Its where the Phantom was powered up and took off from. While this is typically the same place as "your" position, the two are not the same in the overall scheme of things. Your position can move and differ from the "home" position depending on what transpires during the flight. If you stay at the takeoff location, all is good. Its when you move from there during flight that things go wrong really quick.

    Take this scenario: You are on a boat in a lake. You fire up and take off from the foredeck. With the phantom in the air your boat begins towing a skier behind and you do some nice follow shots of the action. Battery gets low and the phantom goes into RTH mode. Where is it going to go?
    1. Back to the foredeck of your boat in front of you?
    2. Back to where the foredeck was when it took off?

    Answer: 2. And the Phantom takes a swim unless you stop it and manually land or get your boat back to where you started this adventure before the Phantom gets there.

    That happens unless you update the home location with your current location (dynamic home point in terms of Litchi) as the boat moves about the lake. This requires GPS coordinates be available to your tablet. This means it needs GPS hardware or access to it via BT for example. The GPS position is read, sent to the RC and is relayed to the Phantom to store as its new "home" position. No GPS on your tablet, then this can't happen.

    The critical thing to consider is that the "home" point is just a point in space (longitude, latitude and altitude or x,y,z) to the Phantom. The phantom doesn't know what it took off from, be that hard ground, the bed of your pickup, the front of a swamp buggy or the deck of a boat. It simply knows where it took off from. If the home point stops being a viable surface to land on, the Phantom has no cognitive way to discern that. It simply knows it needs to return to (x,y,z) before the battery goes dead. If that (x,y,z) is no longer a boat deck but is open ocean now because the boat moved, the phantom is still going to attempt to land there.

    Now, consider scenario #2: You are on a boat offshore but this time you have a device with no GPS. You again take off from the foredeck. This time you are out shooting video of a boat race (sail or power, doesn't matter). Your boat is drifting along in the current but you don't really notice that as you are focused on keeping the phantom aimed at the action of the other boats. You have also lost sight of your phantom by using goggles or being too focused on the FPV or simply flying too far to actually see it. Phantom battery gets low and goes into RTH mode. Now what is going to happen?
    1. Phantom comes back to the foredeck of your boat in front of you?
    2. Phantom goes back to where the foredeck was when it took off?

    Answer: 2. Again. But this time you are pretty screwed. You only know on the map where home was and where the phantom is. You have no clue where you are because you have no GPS and as such have no way to guide the phantom to you, which is where its only hope of landing on anything solid is. If it can reach shore on low battery being manually flown and guided by the cached maps you have, then maybe there is hope. If shore is too far from home or where phantom is, well, its getting wet.

    If you never move from the "home" point, then there is little need for GPS in your device because your position and the home position are, for all practical purposes, the same place. RTH will bring it back to you (or precisely, the home point). You can guide it back to you using the map and bearing indicators because you and home are the same.

    If you ever wish to move from where the phantom took off from, I very seriously recommend you get a device with GPS or get a GPS addon, otherwise you will have very diminished chances of getting your phantom to you rather than its home..
     
    GadgetGuy and Oso like this.
  20. GadgetGuy

    Joined:
    Jun 18, 2015
    Messages:
    4,452
    Likes Received:
    1,294
    Well said! :cool: I will add to this the importance of turning Smart Go Home "OFF", if you have ever moved from your Home Point. Smart Go Home alone is the biggest cause of problems in this scenario! Turn it OFF! :eek: