Is GPS over Bluetooth Low Energy LE (BT 4.0) supported?

Falco shared this question 3 months ago
Answered

I know that many BLE sensors are supportet. What about GPS? Currelty I know only one BLE device: GL-770.


Could I use something like this:

http://www.xdappfactory.com/wp/?page_id=222

This is based on https://github.com/RomainQuidet/LELocation-framework-iOS/blob/master/CHANGELOG.md which does support GL-770 and other Nordic nRF51822 devices


Or could locus use BT4.0?


I do ask because BT4.0 got announced with faster reconnect behaivor and I have trouble with reconnection: http://help.locusmap.eu/topic/bt-gps-reconnection-time-take-some-minutes


I would expect that this bug is based on BT limitations, even if I do consider the manual reconnecting workarround as automated solution it would be still take half a minute instead of 3 minutes.


Maybe the correct solution is the new BT protocol?


Kind Regards

Falco

Best Answer
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The actual topic, hidden behind the key word BT4.0 was: fast reconnection and power saving (save weight). First part was actually a bug and secound part does not make sense based on the only available device GL-770


If we get lightweight BT4.0 devices with less features, then we should reevalute this topic.


And logging with Android to save the weight of an external GPS device is still a waste of weight because there is to much overhead with android and even if we just look at hardware level, a wakeup of a high performance CPU every second is still more expensive then dedicated GPS logging hardware.


GPS watches and very small GPS bicycle computers are to bad as well because it's to difficult to develop a GPS antenna which is not blocked by the display and which is strong enoght to keep up with my 14g solution.

Comments (10)

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Good day Falco once more,

GPS over BT4.0 protocol is currently not yet supported by Locus Map app. I'm aware that there exists some BT4 based GPS receivers, but interest is still quite low and because quality of GPS in devices is increasing and price of Power banks is lower and lower ...

Anyway seems that mentioned app ( https://play.google.com/store/apps/details?id=com.xdappfactory.legpsrec ), should be able to connect to these devices and also forward received location to Locus Map, so give it a try.

Menion

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Thank you for your fast response.


That is bad, my usecase "GPS recording with occasionally map checks as lightwight as possible" isn't that usual. And as long as GPS recording does prevent the huge smartphone CPUs from sleeping it is always a waste of power (weight) to record with android.

If an BT4.0 external app does prevent android from entering sleep states, than it wouldn't have any benefit for my usecase.

@Menion would it may be possible based on android API to implement an external GPS app with doesn't prevent android from sleeping? If you say no then I don't even need to spend time searching for it.


Kind Regards

Falco

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Hello, sure you are welcome.

If you really care so much about battery, isn't better solution


  • use internal GPS + some alternative power source to re-charge during trip (power bank)
  • or directly use this external BT GPS as track logger and Locus Map use with internal GPS only for a quick check of position on the map?

After a trip, it should be probably possible to get data from BT GPS and import them into Locus or any other software.

And about sleep ... simply say, worst for a battery is screen on, then internal GPS and then BT 3.0 (and far away BT 4.0). Anyway when you will use Locus Map for a recording track, then no matter if source of location will be external GPS or internal, Locus Map will keep device awake because it have to every second handle new location. So, then really best should be to use BT GPS as only logger. On second side, I have quite possitive experience with full day logging with internal GPS and aeroplane mode. It depends ...

Not sure I help you. Just info: support for BT4.0 GPS currently do not have high priority, sorry.

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I thought about internal GPS for occasionally map checks.

But my S4 mini can't get an fix in the forrest. Sometimes it get it but only after 3-5minutes.

I would like to have a new one anyway, but there is no new Smartphone with less or equal 110g. Only some entry level ones with 512mb or 1024mb RAM.

I will have a look at Phicomm Energy 4S if it does realy weight only 85g.

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As expected Phicomm Energy 4S doesn't weight 85g, it does weight 143g. Which means, there is nothing better then a S4 mini if you want to have less then 110g or more power energy with 110g.

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I found a solution for my equipment weight problem, a stripped Q1300:

2261402-y8693jysdpid-20180420_02048l_-medium


+9g will double the runtime. And without case the small antena got nearly same signal strength as the big one of the old 64g device.

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Good day Falco,

seems you care about every gram, nice toy :).

I'm anyway little lost now ... this topic was mainly about a possibility to use external BT4.0 GPS device. As I wrote, Locus Map does not support it in this moment. Were you success with any 3rd party application like mentioned LE GPS Rec? Such information may be useful for other users interested in the same use-case. Thanks.

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The point is, you can't use BT4.0. The only advantage is reconnection time and power saving. As long as there are is only one heavy device available you wouldn't get any benefit from it. Because if you reduce your battery weight you will still carry more weight.

It's more easy to stay at BT 2 and add just some gramm for battery.

I did not try to test LE GPS Rec because if there is any wakelock cased by the third party app you will drain your battery with android system idle instead of using BT 2 and proper system sleep.


The main thing is, I can't test LE GPS Rec without wasting 90$ for a GL-770


If anybody care about battery drain, just add some battery weight to your system instead of spending weight in an expensiv and heavy GL-770.

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Good evening Falco,

useful information, thanks!

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1

The actual topic, hidden behind the key word BT4.0 was: fast reconnection and power saving (save weight). First part was actually a bug and secound part does not make sense based on the only available device GL-770


If we get lightweight BT4.0 devices with less features, then we should reevalute this topic.


And logging with Android to save the weight of an external GPS device is still a waste of weight because there is to much overhead with android and even if we just look at hardware level, a wakeup of a high performance CPU every second is still more expensive then dedicated GPS logging hardware.


GPS watches and very small GPS bicycle computers are to bad as well because it's to difficult to develop a GPS antenna which is not blocked by the display and which is strong enoght to keep up with my 14g solution.