The Eggfinder Mini - A Very Small GPS Tracker

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Both will be available. The Eggfinder TX has the capability for an external antenna connector, the Mini has a permanent screw-mount antenna. The TX may still be a better choice for some applications.
 
Cris, does the transmitter sit underneath the GPS? Just wondering if there might be an impact on GPS ability to lock in marginal circumstances. A photo of the other side will be nice. Also those screw holes, will they be open in final version?
 
Cris, does the transmitter sit underneath the GPS? Just wondering if there might be an impact on GPS ability to lock in marginal circumstances. A photo of the other side will be nice. Also those screw holes, will they be open in final version?

Where the Rf module sits has no bearing on the GPS receiver. One just wants the GPS antenna "pointing out". The Rf modules energy is routed out the
antenna so where it sits on the board is irrelevant.

The screw hole thing could be of concern for someone who would plan to mount this in a larger tube. If in a minimum diameter project, would just need fore and aft
thrust blocks as the tube would keep the unit in place. Choose the EF according to what it is going to be used for. Kurt
 
The RF module is indeed underneath the GPS, however the ground plane for the GPS patch antenna is actually the metal can on top of the GPS module. There's a ground plane on the PC board immediately underneath the module. In my flight tests, it does take a little bit longer to get the initial fix, but once it gets it there's no difference.

Also, on the production board, the mounting holes are closed up.
 
I have to ask- I know there are Android apps for this. Are there apps for iOS that would allow me to use my iPhone to identify the rocket on a a map as well as where I am?
 
I have to ask- I know there are Android apps for this. Are there apps for iOS that would allow me to use my iPhone to identify the rocket on a a map as well as where I am?

I use MotionX on my iPhone, it has a map function if you have Internet access but I don't use it. It's not very useful on a dry lakebed and some of the sites I fly at have no Internet so the maps wouldn't work anyway. Some programs will allow you to pre-cache the maps so you can use them offline, but I don't know which ones those are... Kurt, are you out there! :)
 
I use MotionX on my iPhone, it has a map function if you have Internet access but I don't use it. It's not very useful on a dry lakebed and some of the sites I fly at have no Internet so the maps wouldn't work anyway. Some programs will allow you to pre-cache the maps so you can use them offline, but I don't know which ones those are... Kurt, are you out there! :)

So, the receiver with either output to a computer, or the receiver with display. From there, manual entry into gps app like Motion X.
 
Or manual entry to a range x bearing compass app. We use one of those.

Given that JL Alt3 talk directly to an iPhone, it seems like using a Bluetooth serial adapter on the EggReceiver to send data to an iPhone ought to be -theoretically- possible. But I bet it would have to be a custom built app. I seem to recall that John Beans had a bit of a challenge to get that all working.
 
From a hardware point of view, yes, Bluetooth to an iPhone is certainly possible. Unfortunately, Apple does not support either serial Bluetooth devices nor external GPS devices in iOS, so you can't do it. Android does, which is why a lot of people use cheap Android tablets with Rocket Locator with their Eggfinder. Personally, I'm OK with manually entering the coordinates into MotionX.

Either the Eggfinder RX "dongle" or the Eggfinder LCD display receiver can be used with an HC06 Bluetooth module to provide a wireless feed to an Android running Rocket Locator. With the LCD, you also get the coordinates on the display as a backup... good to have in case you lose the Bluetooth feed.
 
..................Or hack ham radio software to navigate on a map: https://www.rocketryforum.com/showthread.php?137555-Eggfinder-Map-tracks

GPS Rocket Locator is the simplest though. It was advertised as being able to cache Google maps for offline use but I believe that is no longer the case.
I emailed the author and he said he will look into it. I noticed it when I tried to cache with a $49.00 Teclast X80a Christmas special. Might have been
my device though. On the flip side, the Open Source maps downloaded and cached properly. It's easy to simply walk toward the last known position and
of course when a new final position comes in, you have it made. Kurt
 
From a hardware point of view, yes, Bluetooth to an iPhone is certainly possible. Unfortunately, Apple does not support either serial Bluetooth devices nor external GPS devices in iOS, so you can't do it.

Actually, it's my (unverified so far) understanding that neither of these statements is actually true. The HC06 isn't supported because it's an older Bluetooth flavor, anything that does BTLE (Bluetooth 4.0) is supposed to be supported without any extra magic (pretty sure that's what Jolly Logic is doing). I played with one of the Nordic nRF parts and had it sending canned BT serial data to my iPhone without any extra effort. Problem is I couldn't find any code online that would basically turn the Nordic part into a HC06 clone (i.e. just shuffle bytes between a UART and BT), and it wasn't intuitively obvious how to do this myself so that's where I'm stalled on that effort, otherwise I'd have one wired to my EF LCD already. :)

On the external GPS part, what I've heard (again, unverified) says that once you have the NMEA stream coming in over a (BT) UART, iOS simply starts using it. Though it sounds like it'll start using it as if it was the phone's GPS, so it likely gets in the way of giving you distance and heading, it sounds like it would plot the rocket's position on a map as if the phone was in the rocket (and not have any idea where the *phone* actually is at that point). So that might not be bad for mapping/tracking, but obviously no good for navigating to the rocket. It sounded like this was just how iOS's location services works, so there might not be any way to prevent it such that you could intercept the serial stream and use it as a second set of coordinates while still having access to the phone's coordinates as well (though I guess so long as you made the NMEA stream not-quite-NMEA the OS wouldn't recognize it and you could do your own thing to decode the rocket's location (this would obviously take a custom app however).
 
Maybe I'll snag a BTLE module and see if I can get iOS to do anything useful with it. I'm not gonna reinvent the wheel, though... unless it's an easy hack, something like Rocket Locator for iOS isn't in the cards.
 
Ordered! Been waiting for this to be released! Nice work Cris!
 
Oh, a bit more on-topic than my last post, first off love the smaller EF. My rockets generally have large enough noses that I don't really need a smaller one, but I can see how that would help a lot of smaller rockets. Now I'll have to decide which one to order next time I need more Eggfinders. :)

I assume it's the same Maestro GPS unit? I do wish something better was available here, like a u-blox unit, but I guess they're not as friendly towards hand-soldering? Or is it just a price thing? I'm sure it wouldn't be pin-compatible, but it would be nice if there could be a more expensive option with a GPS receiver that is better at reporting altitude and more likely to remain locked during flight.

And thanks for the Quantum air-start work also!
 
Looks like the Maestro and I think it's a price thing. More than adequate to find the rocket. I hope people read the instructions on air-starting very carefully. AKS
 
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I have yet to see any real reason to change from the Maestro GPS. Other than people accidentally knocking the antenna off (which can be fixed with a little RocketPoxy) it works very well for finding your rocket, which is the ultimate goal of the Eggfinder. For real-time altitude, the TRS which sends baro altitude data is much better, and I bet it works better than a uBlox too up to its limit (about 70K).
 
I second that. The time to apply the epoxy is before the device is flown. I apply a bead along the sides of the GPS assembly not over the contact area fore and aft. Plenty strong to
hold it on. AKS
 
I second that. The time to apply the epoxy is before the device is flown. I apply a bead along the sides of the GPS assembly not over the contact area fore and aft. Plenty strong to
hold it on. AKS

I think I understand what you are saying here, but can you please post a picture that illustrates?
 
I think I understand what you are saying here, but can you please post a picture that illustrates?

Be glad to when I get home tonight. I've wrecked two EF's by dropping them. Was able to convert to off-board Ublox Chipsets but I find that the altitude reporting on to the LCD
to be a bit squirrelly. I sometimes get funny characters instead of something that looks like a legitimate GPS altitude. The altitude is accurately displayed in the strings.
With software decoding, timing I believe is the key but using other GPS chipsets, Ublox or otherwise might lead to differences in altitude reporting. The lat/long of any of the
GPS's I've tried on the ground are fine. I haven't flown a Ublox hacked EggFinder yet as ostensibly it takes more room for the device.

I had a Ublox evaluation unit with a Sarantel circularly polarized antenna but I'll be darned it stopped working. Can't find a replacement for the same type of unit. Kurt
 
I think I understand what you are saying here, but can you please post a picture that illustrates?

Here it is: IMG_20170324_074606.jpg

I use whatever epoxy I have mixed up at the time. Grey is J&B, black is Proline 4500.

Kurt
 
Ordered! :)

Cris, I'm guessing that antenna is a little heavier than the wire antenna from the original EF. Is there anything I need to do to make it ready for a 75G launch? I was already planning on putting some epoxy on anything that sticks up. The antenna mount looks fairly beefy though.

Thanks!
-Bryan
 
Ordered! :)

Cris, I'm guessing that antenna is a little heavier than the wire antenna from the original EF. Is there anything I need to do to make it ready for a 75G launch? I was already planning on putting some epoxy on anything that sticks up. The antenna mount looks fairly beefy though.

Thanks!
-Bryan

The antenna isn't going anywhere, everything else on the board will come off before the antenna does. I would probably hold it down with a zip tie, but that and the two screws should be enough. I prefer nylon screws, but metal is OK too... just use some nylon washers to insulate the screw head and as standoffs.
 
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