Pair GPS receiver per Unleashed versus Pair GPS receiver per Smartphone

[Unfoolishly]

I understand the problem of not having GPS data inside your house, and I understand the use case of needing a GPS receiver sitting by the window, that can relay GPS data to your phone. My question was more about, what is the use case of having some Unleasheds using data from the phone and others using GPS data from a receiver? You said that those GPS receivers wouldn't have data inside anyway.

And why would you want this?

[...] that some Unleasheds use the internal smartphone GPS data and other Unleasheds use the external rerouted GPS data.

Oh, sorry for misunderstanding.

Sometimes you walk in a forest (well, I do sometimes) and the external GPS device losses its GPS satellite fix (due to the trees). Now you can have a problem if you configured the Unleashed to only use the external GPS device as its source (as an accessory). So, better is to have both smartphone and external GPS as source. But, sometimes the opposite is true as well: the external GPS does have a fix, but the smartphone has no fix (no cellphone network in the forest). Still no problem you think, right? But what if there is a certain gap between the two receivers, either the one or the other having a fix for a period of time, not logging the data inside the device? Is it still enough for post-editing the geotag data inside the photo's? The external GPS device does not log GPS data if it has no fix, so "so far for the logging". Logging of the external GPS device is useless if it doesn't contain the logging of the gap-period and you have no backup (smartphone logging).

Concerning the use of the smartphone as the GPS source VERSUS the use of the external GPS receiver as the GPS source:
Simple, sometimes I walk with other people at a location in which the other people do not have a camera themselves (or a smartphone! yes, such people DO exist ;)), so they use one of my camera's. That means one camera moves away from my location (even beyond the 40m distance of the Bluetooth Low Energy range) and thus needs to have the external GPS receiver alongside with it. Otherwise, not geotagging inside the photo's.
Sometimes I let one camera do a timelapse on a fixed location (attic for example) and have that camera/Unleashed paired with the external GPS receiver, while I use other camera(s) for other purposes, thus these camera's are hooked up to my smartphone alone (both of them). Leaving the camera at the attic unattended with the external GPS device next to it.

In the old days (Unleashed'09) each Unleashed had an dedicated external GPS receiver, so this was no 'problem'. But nowadays, this is no longer mandatory due to the smartphones and newer external GPS receivers. Problem is only that when camera's separate each way, outside the Bluetooth range, you have to have a dedicated GPS source. But I don't have 3 separate BT Low Energy GPS receivers nowadays. So what I could do is use an old BT Classic GPS receiver and let it forward its data over the smartphone to two camera's/Unleasheds I am carying along the way into the forest, thus making sure I have best of both worlds: one single external GPS receiver broadcasted over two Unleasheds, through the smartphone and one smartphone as a fallback/backup when the external GPS receiver losses its satellite fix. Then I need to have the Unleasheed App to become a broadcaster of a GPS Provider, thus the GPS Providers should be configured loosly coupled to the smartphone and Unleashed App, meaning: don't pinning the GPS device (either smartphone or external device) to a specific Unleashed, but making it more wider used as in the Publish-Subscribe mechanism. Then you have a "market full of GPS providers" to which anyone can subscribe and unsubscribe (as long as they are in range of the publisher of course.

I hope this answers your question. You are really sharp in questioning today ;-)

Note: this 'problem' was not possible back in the days of the Unleashed'09, but that was because each Unleashed had its own decicated external GPS receiver and there were no smartphones commonly used as remote control and GPS provider. A lot has changed since BT Low Energy became mature enough for better solutions.

Greetings,
Unfoolishly

[Unfoolishly]

Hi Andy,

My own reply rereading, I came up with these thoughts:

If the Unleashed receives no valid GPS data in the input, how much time is waited to switch back to a secondary source, if configured of couse?
In other words: is there a delay in switching from external GPS device to smartphone, and can this delay be configured as well, or is it directly trying to fallback on its secondary source (mostly the smartphone)?

Is it also possible to set the smartphone as the primary source for GPS data and the external GPS device as the secondary source? Sometimes you do have a cellphone network fix but no satellite fix in the location you are shooting photo's (forest vs city).

What happens when the "no valid data" occured for a while and the Unleashed eagerly searches for another source of GPS data? Does the Unleashed starts within a short period of time to try to connect to the smartphone to get the GPS data from that source, or does it wait a while before switching 'channels'?

The reason I am asking is simple: if the Unleashed directly switches back from external GPS receiver towards the smartphone when the former losses its fix, what happens when the smartphone losses its fix? Does it flip 'channels' constantly, or is there a "try-again within a certain period of time"-time setting to prevent switching back and forth between smartphone and external GPS receiver?

Just curious how the Unleashed handels this. I would ASSUME that the Unleashed keeps polling in certain timed moments to detect if the external GPS receiver had gained back its satellite fix. And accepts this source again as its primary source for GPS data.

Greetings,
Unfoolishly

[Andy]

I understand the problem of not having GPS data inside your house, and I understand the use case of needing a GPS receiver sitting by the window, that can relay GPS data to your phone. My question was more about, what is the use case of having some Unleasheds using data from the phone and others using GPS data from a receiver? You said that those GPS receivers wouldn't have data inside anyway.

And why would you want this?

[...] that some Unleasheds use the internal smartphone GPS data and other Unleasheds use the external rerouted GPS data.

Oh, sorry for misunderstanding.

Sometimes you walk in a forest (well, I do sometimes) and the external GPS device losses its GPS satellite fix (due to the trees). Now you can have a problem if you configured the Unleashed to only use the external GPS device as its source (as an accessory). So, better is to have both smartphone and external GPS as source. But, sometimes the opposite is true as well: the external GPS does have a fix, but the smartphone has no fix (no cellphone network in the forest). Still no problem you think, right? But what if there is a certain gap between the two receivers, either the one or the other having a fix for a period of time, not logging the data inside the device? Is it still enough for post-editing the geotag data inside the photo's? The external GPS device does not log GPS data if it has no fix, so "so far for the logging". Logging of the external GPS device is useless if it doesn't contain the logging of the gap-period and you have no backup (smartphone logging).

Concerning the use of the smartphone as the GPS source VERSUS the use of the external GPS receiver as the GPS source:
Simple, sometimes I walk with other people at a location in which the other people do not have a camera themselves (or a smartphone! yes, such people DO exist ;)), so they use one of my camera's. That means one camera moves away from my location (even beyond the 40m distance of the Bluetooth Low Energy range) and thus needs to have the external GPS receiver alongside with it. Otherwise, not geotagging inside the photo's.
Sometimes I let one camera do a timelapse on a fixed location (attic for example) and have that camera/Unleashed paired with the external GPS receiver, while I use other camera(s) for other purposes, thus these camera's are hooked up to my smartphone alone (both of them). Leaving the camera at the attic unattended with the external GPS device next to it.

In the old days (Unleashed'09) each Unleashed had an dedicated external GPS receiver, so this was no 'problem'. But nowadays, this is no longer mandatory due to the smartphones and newer external GPS receivers. Problem is only that when camera's separate each way, outside the Bluetooth range, you have to have a dedicated GPS source. But I don't have 3 separate BT Low Energy GPS receivers nowadays. So what I could do is use an old BT Classic GPS receiver and let it forward its data over the smartphone to two camera's/Unleasheds I am carying along the way into the forest, thus making sure I have best of both worlds: one single external GPS receiver broadcasted over two Unleasheds, through the smartphone and one smartphone as a fallback/backup when the external GPS receiver losses its satellite fix. Then I need to have the Unleasheed App to become a broadcaster of a GPS Provider, thus the GPS Providers should be configured loosly coupled to the smartphone and Unleashed App, meaning: don't pinning the GPS device (either smartphone or external device) to a specific Unleashed, but making it more wider used as in the Publish-Subscribe mechanism. Then you have a "market full of GPS providers" to which anyone can subscribe and unsubscribe (as long as they are in range of the publisher of course.

I hope this answers your question. You are really sharp in questioning today ;-)

Note: this 'problem' was not possible back in the days of the Unleashed'09, but that was because each Unleashed had its own decicated external GPS receiver and there were no smartphones commonly used as remote control and GPS provider. A lot has changed since BT Low Energy became mature enough for better solutions.

Greetings,
Unfoolishly

Sorry, but even after all you've written I still don't think I understand the need for the "separate GPS-to-smartphone internal data rerouting per Unleashed" feature. Your use cases of going to the forest and getting no signal, or lending your camera to people away from you are valid use cases, but they are already addressed by the "External GPS + Smartphone fallback" GPS mode. Even when the fix of either the smartphone or the external receiver is lost, as long as one of them (doesn't matter which one) has a fix, your Unleashed should geotag the photos with data from the one source that does have a fix.

[Andy]

If the Unleashed receives no valid GPS data in the input, how much time is waited to switch back to a secondary source, if configured of couse?
In other words: is there a delay in switching from external GPS device to smartphone, and can this delay be configured as well, or is it directly trying to fallback on its secondary source (mostly the smartphone)?

Is it also possible to set the smartphone as the primary source for GPS data and the external GPS device as the secondary source? Sometimes you do have a cellphone network fix but no satellite fix in the location you are shooting photo's (forest vs city).

What happens when the "no valid data" occured for a while and the Unleashed eagerly searches for another source of GPS data? Does the Unleashed starts within a short period of time to try to connect to the smartphone to get the GPS data from that source, or does it wait a while before switching 'channels'?

The reason I am asking is simple: if the Unleashed directly switches back from external GPS receiver towards the smartphone when the former losses its fix, what happens when the smartphone losses its fix? Does it flip 'channels' constantly, or is there a "try-again within a certain period of time"-time setting to prevent switching back and forth between smartphone and external GPS receiver?

That's a good question, I actually didn't even remember how it works so I had to go look at the code for the GPS handling.

The Unleashed will start requesting GPS data from the app if the GPS mode is set to "External + Smartphone" and there is an error with the GPS data. Possible errors are "no external GPS connected", "GPS data from fallback source (smartphone)", "old GPS data" and "no data at all". So to answer your question, the Unleashed will start requesting GPS data as soon as the last GPS data point is considered old (which is going to be a configurable time with hopefully the next release). When the Unleashed receives valid GPS data again from the external GPS, the previous "GPS data from fallback source" error gets cleared and the Unleashed stops requesting data from the app.

Naturally, in order for the Unleashed to request GPS data from the app, the smartphone needs to be connected in the first place. And if the smartphone loses its fix, the Unleashed will still continue requesting GPS data from the app, even if it's not getting any. The Unleashed will be blinking red until the external GPS is connected again and it gets a fix.

I will add this information to the manual (work in progress) before I forget.

[Unfoolishly]

...
And why would you want this?

...

Sorry, but even after all you've written I still don't think I understand the need for the "separate GPS-to-smartphone internal data rerouting per Unleashed" feature. Your use cases of going to the forest and getting no signal, or lending your camera to people away from you are valid use cases, but they are already addressed by the "External GPS + Smartphone fallback" GPS mode. Even when the fix of either the smartphone or the external receiver is lost, as long as one of them (doesn't matter which one) has a fix, your Unleashed should geotag the photos with data from the one source that does have a fix.

Here is the usecase you are looking for:

Using the smartphone in home (without cellphone network, wifi network and gps satellite fix) to operate multiple Unleasheds. That means, the user controls the camera's by the Unleasheds, but the smartphone is not DIRECTLY used for geotagging! Now the user wants to make sure that all the Unleasheds receive GPS data. The only way to do that is to get outside (outside any concrete building blocking the signals) and catch some network/satellite fix. But the moment you go inside, you will probably loose that fix again due to the concrete walls. Now some cool feature comes into play: place one single external GPS receiver in the garden or on the balcony and let that GPS receiver forward the GPS data towards the smartphone which then can distribute to each and every Unleashed that is subscribed to that GPS Provider within the Unleashed App. That means the following:

Input: 1 single GPS receiver (BT Classic or BT Low Energy)
Intermediator: 1 single smartphone (distributing to all Unleasheds subscribed)
Output: all Unleasheds subscribed to the Unleashed App

That way you can serve many Unleasheds with only ONE external GPS receiver, and not the smartphone. The smartphone in this usecase is NOT the source of the GPS data, but the forwarder of the GPS data! That way the smartphone is in control of controlling the camera's AND is in control for making sure the Unleasheds also receive the GPS data for geotagging.

To me this is a valid usecase...

Somedays I am just on fire ;-)
( see: https://www.youtube.com/watch?v=eqY_Vp-xj4A )

One GPS receiver to supply them all, one smartphone to control them all.
( See: https://www.youtube.com/watch?v=lMSLM33PQDM )

Greetings,
Unfoolishy

[Unfoolishly]

...

That's a good question, I actually didn't even remember how it works so I had to go look at the code for the GPS handling.

The Unleashed will start requesting GPS data from the app if the GPS mode is set to "External + Smartphone" and there is an error with the GPS data. Possible errors are "no external GPS connected", "GPS data from fallback source (smartphone)", "old GPS data" and "no data at all". So to answer your question, the Unleashed will start requesting GPS data as soon as the last GPS data point is considered old (which is going to be a configurable time with hopefully the next release). When the Unleashed receives valid GPS data again from the external GPS, the previous "GPS data from fallback source" error gets cleared and the Unleashed stops requesting data from the app.

Naturally, in order for the Unleashed to request GPS data from the app, the smartphone needs to be connected in the first place. And if the smartphone loses its fix, the Unleashed will still continue requesting GPS data from the app, even if it's not getting any. The Unleashed will be blinking red until the external GPS is connected again and it gets a fix.

Somehow I think it isn't handled for the full 100% yet.

What I am looking for is the scenario in which the smartphone takes over the role of the external GPS receiver (due to lost fix) but suddenly you walk/move/travel towards a location in which the situation is completely reversed (that can happen when, for example, you travel by train going through rural areas versus going through urban areas). What you will get is a "back-and-forth" switching, which can be annoying if it switches so quickly. At least, that is my assumption :-)

"the Unleashed will start requesting GPS data as soon as the last GPS data point is considered old (which is going to be a configurable time with hopefully the next release)".

That means the Unleashed won't contact the smartphone right away when the GPS fix on the external receiver is lost, but only after the "holdtime" is expired the Unleashed starts looking for a different source (= the smartphone). But this brings some thoughts to my attention. What if the external GPS receiver runs dead on battery power? Then the holdtime starts to count down (or up, as you prefer) but it can never reconnect to the external GPS receiver again, until the battery gets charged or replaced. That means that the Unleashed shouldn't wait the entire "holdtime" to start a reconnect to the external GPS receiver or wait for the external GPS receiver get a new fix. Because that won't happen at all.

Sidethought: is it possible for the Unleashed to fetch the battery level information over the BT Low Energy connection with these new BLE GPS receivers nowadays? That would give the Unleashed some advantage in order to determine what it can expect within a certain amount of time: either the GPS fix drops or the Bluetooth LE connection drops.

Now consider the data received to be old (holdtime exceeded, for example, the user set it to 15 minutes). What should the Unleashed do after the holdtime is expired? Connect to the smartphone after those 15 minutes, or before those 15 minutes, but not accept the incoming (valid) GPS data from the smartphone already as the primary source of data. That is: keep the "old GPS data" until the holdtime is expired and after that time update the GPS data within the Unleashed to the "new GPS data" of the smartphone? Or connect to the smartphone after 50% of the holdtime is expired and assume that the external GPS receiver won't make it in time to restore/recover from the "hickup" (either GPS fix lost or disconnection of the BT) BUT keep waiting for a full restore within the full holdtime (100%) and when the external GPS data is back online within this holdtime, continue using this source of information for the GPS data?

Remember that the user, if he/she is not using the smartphone, thus the Unleashed App is not running at all, needs time to turn on his/her smartphone, and this will take a while. Of course it is always better to start the App anyways, but not all users do that when they trust that they have an external GPS receiver as their trusting source or GPS data.

Now you have a holdtime to go after the fallback/backup source (smartphone), but is there also a holdtime to revert back to the original source? That means: after "switchtime" has expired, fall back to the external GPS receiver again? It could be that the battery has not run dead, but the camerabag that had the GPS receiver in it just went out of BT range, and now has come back into BT range and thus the Unleashed can revert back to the external GPS receiver again, switching back from smartphone to GPS receiver. In other words: you have two types of "holdtime", one for the GPS-receiver-to-smartphone-holdtime and one for the Smartphone-to-GPS-receiver-holdtime. If I am correctly informed, that is ;-)

You can give your camera to another person (because you have mounted another lens on the body) but leave the smartphone in your pocket/jacket and the other person walks away, out of range of your smartphone, but back into range with the external GPS receiver. Then you get this "old data"-story of the Unleashed for both devices:

old data in Unleashed from smartphone
old data in Unleashed from external GPS receiver

"The Unleashed will be blinking red until the external GPS is connected again and it gets a fix."

This is somewhat mysterious to me, because you can have a fix, have valid data (not expired data) but are connected to a source you do not expect to be connected to. That is: you THINK you are receiving the GPS data from the external GPS receiver but actually receive it from the smartphone or vise versa. That means there is something wrong with the external GPS receiver reception or Bluetooth connection, and that is not shown directly to the user IF the smartphone is connected and providing the GPS data. At least, that is my assumption. Maybe this is also something for the manual.

I think there needs to be some distinction in the LED coloring or blinking, or both, so that the user can see and know which GPS source is currently the Unleashed's GPS provider: the accessory or the smartphone? Why, because not all users use the smartphone while shooting and holding the camera. They don't look at the smartphone, but they look at the camera screen if the GPS icon is on or off. And also look at the Unleashed LED colorings.

So, somehow, this usecase is not yet fully nailed down.

I will add this information to the manual (work in progress) before I forget.

That is a really good idea, Andy! Keep it up! You're doing great! Give us the holy grail of manuals, soon please ;-)

Greetings,
Unfoolishly

[Andy]

Here is the usecase you are looking for:

Using the smartphone in home (without cellphone network, wifi network and gps satellite fix) to operate multiple Unleasheds. That means, the user controls the camera's by the Unleasheds, but the smartphone is not DIRECTLY used for geotagging! Now the user wants to make sure that all the Unleasheds receive GPS data. The only way to do that is to get outside (outside any concrete building blocking the signals) and catch some network/satellite fix. But the moment you go inside, you will probably loose that fix again due to the concrete walls. Now some cool feature comes into play: place one single external GPS receiver in the garden or on the balcony and let that GPS receiver forward the GPS data towards the smartphone which then can distribute to each and every Unleashed that is subscribed to that GPS Provider within the Unleashed App. That means the following:

Input: 1 single GPS receiver (BT Classic or BT Low Energy)
Intermediator: 1 single smartphone (distributing to all Unleasheds subscribed)
Output: all Unleasheds subscribed to the Unleashed App

That way you can serve many Unleasheds with only ONE external GPS receiver, and not the smartphone. The smartphone in this usecase is NOT the source of the GPS data, but the forwarder of the GPS data! That way the smartphone is in control of controlling the camera's AND is in control for making sure the Unleasheds also receive the GPS data for geotagging.

I think at this point we are repeating ourselves haha. I understand that use case, but as I said before, I think this is already possible by just connecting a GPS receiver directly to the smartphone, which then overrides the GPS data provided by the OS (I believe).

So, I still don't understand the need for the "separate GPS-to-smartphone internal data rerouting per Unleashed" feature. You said before that you would like to have some Unleasheds get data directly from the smartphone, and some others getting forwarded data. Why isn't "forwarded-data for ALL Unleasheds" enough?

[Andy]

Somehow I think it isn't handled for the full 100% yet.

What I am looking for is the scenario in which the smartphone takes over the role of the external GPS receiver (due to lost fix) but suddenly you walk/move/travel towards a location in which the situation is completely reversed (that can happen when, for example, you travel by train going through rural areas versus going through urban areas). What you will get is a "back-and-forth" switching, which can be annoying if it switches so quickly. At least, that is my assumption :-)

It doesn't switch quickly, the data has to become "old" first. You will be able to say how fast this happens.

What if the external GPS receiver runs dead on battery power? Then the holdtime starts to count down (or up, as you prefer) but it can never reconnect to the external GPS receiver again, until the battery gets charged or replaced. That means that the Unleashed shouldn't wait the entire "holdtime" to start a reconnect to the external GPS receiver or wait for the external GPS receiver get a new fix. Because that won't happen at all.

The Unleashed already starts requesting GPS data from the app immediately on disconnection. It doesn't wait for any hold time.

Sidethought: is it possible for the Unleashed to fetch the battery level information over the BT Low Energy connection with these new BLE GPS receivers nowadays? That would give the Unleashed some advantage in order to determine what it can expect within a certain amount of time: either the GPS fix drops or the Bluetooth LE connection drops.

I guess that varies from vendor to vendor. We don't control what information the different GPS receivers give access to. In any case, it is not necessary to prepare for disconnection.

Now consider the data received to be old (holdtime exceeded, for example, the user set it to 15 minutes). What should the Unleashed do after the holdtime is expired? Connect to the smartphone after those 15 minutes, or before those 15 minutes, but not accept the incoming (valid) GPS data from the smartphone already as the primary source of data. That is: keep the "old GPS data" until the holdtime is expired and after that time update the GPS data within the Unleashed to the "new GPS data" of the smartphone? Or connect to the smartphone after 50% of the holdtime is expired and assume that the external GPS receiver won't make it in time to restore/recover from the "hickup" (either GPS fix lost or disconnection of the BT) BUT keep waiting for a full restore within the full holdtime (100%) and when the external GPS data is back online within this holdtime, continue using this source of information for the GPS data?

The Unleashed never drops the connection to the phone. It will try to reconnect to the app regardless of the current GPS mode. It will only drop the connection when going to sleep (time to sleep and whether the connection should be dropped or not will also be user configurable).

Remember that the user, if he/she is not using the smartphone, thus the Unleashed App is not running at all, needs time to turn on his/her smartphone, and this will take a while.

There's nothing we can do about that. The Unleashed can't open the app on your phone for you.

Now you have a holdtime to go after the fallback/backup source (smartphone), but is there also a holdtime to revert back to the original source? That means: after "switchtime" has expired, fall back to the external GPS receiver again? It could be that the battery has not run dead, but the camerabag that had the GPS receiver in it just went out of BT range, and now has come back into BT range and thus the Unleashed can revert back to the external GPS receiver again, switching back from smartphone to GPS receiver. In other words: you have two types of "holdtime", one for the GPS-receiver-to-smartphone-holdtime and one for the Smartphone-to-GPS-receiver-holdtime. If I am correctly informed, that is ;-)

The Unleashed will always try to get GPS data from the receiver, even if when it's already requesting GPS data from the app. As soon as the receiver sends some valid data, the Unleashed will stop requesting data from the app.

This is somewhat mysterious to me, because you can have a fix, have valid data (not expired data) but are connected to a source you do not expect to be connected to. That is: you THINK you are receiving the GPS data from the external GPS receiver but actually receive it from the smartphone or vise versa. That means there is something wrong with the external GPS receiver reception or Bluetooth connection, and that is not shown directly to the user IF the smartphone is connected and providing the GPS data. At least, that is my assumption. Maybe this is also something for the manual.

I think there needs to be some distinction in the LED coloring or blinking, or both, so that the user can see and know which GPS source is currently the Unleashed's GPS provider: the accessory or the smartphone? Why, because not all users use the smartphone while shooting and holding the camera. They don't look at the smartphone, but they look at the camera screen if the GPS icon is on or off. And also look at the Unleashed LED colorings.

It is shown. The Unleashed will be blinking red to let you know that there is an error. If you open the app to check what is going on, the app will tell you that the Unleashed is getting data from the fallback source. If you want to get rid of that error you have to either check what's going on with your GPS receiver or change the GPS mode to smartphone only. You can test that if you want.

[Unfoolishly]

I think at this point we are repeating ourselves haha. I understand that use case, but as I said before, I think this is already possible by just connecting a GPS receiver directly to the smartphone, which then overrides the GPS data provided by the OS (I believe).

So, I still don't understand the need for the "separate GPS-to-smartphone internal data rerouting per Unleashed" feature. You said before that you would like to have some Unleasheds get data directly from the smartphone, and some others getting forwarded data.

Why isn't "forwarded-data for ALL Unleasheds" enough?

Good question! Normally this would be enough to forward a single external GPS signal towards the Unleashed App and to ALL Unleasheds, but there are some circumstances in which you would like to forward a specific external GPS signal to a specific Unleashed while the other Unleasheds receive either the internal GPS data of the smartphone OR the external GPS data of another external GPS receiver.

Here is such circumstance in a single picture:

external-gps-forwarding.png

As you can see, the external GPS receiver on location B is unsupported in terms of being able to hook it up as an accessory directly to the Unleashed of location B. But this external GPS receiver can be used anyhow, by creating a GPS Provider in the Unleashed App so that the external GPS receiver can be hooked up to the App which then forwards the received GPS data towards the Unleashed on location B.

Some situations/circumstances:
- within a (large) building use camera's in different locations
- in nature, having camera's set up in different locations
- on the road: while person 2 is walking with camera 2, person 1 walks with camera 1 (not sharing the SAME location, but external GPS signal of GPS receiver 2 is transmitted over the smartphone of person 1. Making the smartphone of person 1 the Man-in-the-Middle broadcaster. That way both persons have their own location, with a maximum of 40m (due to Bluetooth range limits).

This is what I can think of. By making the Unleashed App able to broadcast several external GPS receivers, as GPS Providers, you are less limited to your physical location in terms of getting the exact geotag in the photo.

You could of course use another smartphone on location B and set up that smartphone as a Man-in-the-middle for the external GPS receiver on location B. But that gives you no longer the oppertunity to control the camera from the smartphone on location A, if that is what you want.

I do see some benefits in handling GPS Providers that can be hooked up to the smartphone, either BT Classic or BT Low Energy:
- BT LE device not yet supported by Unleashed firmware.
- BT Classic device can be used as well.
- Want to control several camera's on different locations, with exact location data from that location and not from the smartphone controlling the camera's.
- Smartphone used as an extender in terms of Bluetooth range extender (sort of BT signal repeater) of the BT LE or BT Classic GPS receiver.
- etc.

I think there are a few usecases to mention that comes to mind. At least you could think of making the Unleashed App more flexible in terms of using accessories, not only GPS devices, but other devices as well, like a Bluetooth remote control, a Bluetooth tag, a Bluetooth sensor, etc. So the term "Provider" can be used for "GPS Provider" but also for other devices you can hook up to your SMART-phone. The Unleashed can be used to hook up other accessories directly, but you can also see the Unleashed App in combination with the Unleashed as an accessory extender, so the productportfolio is enlarged for the Unleashed family using the smartphone as an indirect accessory extender. Example: when a marathon runner (having a ChampionChip on his/her wrist passes along a detectiongate for ChampionChip chips. That signal can be used to trigger an Unleashed to take a photo of that moment!

I can come up with many more ideas.

Greetings,
Unfoolishly

[Oliver]

1) External GPS receivers can be used to provide a smartphone with GPS data for the entire system. For instance the Bad Elf GPS Pro series can do this for iOS, but AFAIK, not for Android. From what i read, there are apps that will take GPS data from an external GPS and forward it to the Android operating system. Any Unleashed set to use the GPS location from the smartphone will then in turn use the one from the external GPS.

2) We're not planning to add any features that apply exclusively to using multiple unleasheds being used in edge-case scenarios. So while you might be able to find these unlikely edge-cases, we won't ever be able to justify putting any effort into handling those.

3) If you're in a situation where some GPS receivers might not have reception, but the smarpthone does still have a position (from its internal or an external smartphone, chances are extremly high that the precision of that GPS position you still have is WAY worse than the maximum range of BLE. In other words, those (maximally) 40m are not going to make a difference.
Nonetheless, for this special case that you drew, you're simply going to have to buy a dedicated GPS receiver for that one Unleashed that's 40m away from the others, and set that Unleashed to only use GPS data from the external source, whereas the others close to the smartphone can be set to external with smartphone fallback.