Just for fun: Eggfinder to iPhone via Bluetooth

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Amateur Propulsionist
TRF Supporter
Jan 11, 2012
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Central Virginia
Just sharing for those that might be interested.

It's been mentioned elsewhere that the HC-06 bluetooth module often used with the Eggfinder LCD doesn't play nice with IOS (iPhones, etc.) In another thread someone mentioned the newer HM-10 modules ARE supported on IOS, so I thought I've play with one.

Here's a snippet of my Eggfinder LCD receiver streaming data to my iPhone in real time.


At this point it only proves connectivity and that data can be received. It needs an app to actually be useful.
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Did you verify that something like the Maps app didn't just start using the EF's GPS location instead of the phone's? There are several sites on the web suggesting that this is what happens once a Bluetooth NMEA stream starts coming in (as there are 3rd party external GPS receivers that claim to work in all iOS apps without any jailbreaking, etc). So it sounded like it should 'just work', though a few things mentioned needing to disable the internal GPS (going to Airplane mode and then re-enabling Bluetooth was the 'easy way', though other sites said this step was unnecessary). Of course Maps gets pretty unhappy without a network connection, if you have Motion-X it should work fine without one (at least I've never had trouble at Black Rock where I've never had cellular data).
You might be able to set your current location as a "home" waypoint, then start your GPS feed and when it stops set a waypoint there, and have it track from "home" to the end waypoint. It would depend on the software...
From what I've learned thus far, you don't pair and connect to the BLE module via the iPhone Bluetooth setup screen (as you would for a bluetooth headset for example.) Instead, within an app that's designed to do it, you select an available BLE device, and then connect to it. I probably installed a dozen apps before I found one that recognized the BLE device and knew what to do with the data it received.

This particular app, "BLE Serial" simply connects to the module, then receives whatever data the module sends. It doesn't know what NMEA strings are - it's just ASCII data. I next downloaded another dozen or so apps that were designed to read NMEA strings or BLE GPS devices, and have not yet found one that recognizes the data or the device. An app would need to be designed to connect to the BLE device, know how to parse the data, and do something with it. There may be one out there that I just have not yet found.
Great for iPhone users. The trick is search for an app you can pipe the NMEA to and get it plotted on a map. I don't know if iPhone allows "mock locations" like Android. There is an app called Bluetooth GPS that when "allow mock GPS locations" is selected
can have the device "use" the incoming datastream from the Eggfinder as the "local" GPS source. You can see where this is going. Call up a mapping program and it uses that to plot "your" location which is actually the rocket. Of course this isn't
any good for navigating "to" the rocket per se because you aren't able to show your local position.

I do like this program as I can check the rocket on the pad and see how many satellites it has a lock on. I then cancel "allow mock GPS locations" and fire up the GPS Rocket Locator app and use it for navigation.

Sorry for the hijack Bill but nice to see you've made the progress to get the datastream decoded on the iPhone. That could make rocket people happy. If the stream could be piped to an already available iPhone tracking app, it might
prove helpful at least visualizing a rockets location. Kurt
Agreed Kurt - I'm still searching for an existing iphone app that can make the BLE connection *and* know what to do with the data. I came close with some drone software, but still no dice. I'm guessing there's one out there, either in the UAV, aeronautics, or mapping space that can connect and read NMEA sentences.

Big haystack, small needle. Still searching...
Have you tried
NMEA Talker by Aman Enterprises Inc

They have a web video showing serial to Bluetooth to iPad replacing the iPad's gps location. They make the iPad think it's in different locations by feeding it simulated NMEA strings.
Yeah, The gold standard is having a device automatically track and compute a navigation solution while the rocket is in flight. That's been around since the 70cm APRS Beeline GPS for I believe 8 or 9 years. Only problem was the cost factor and requirement of a Ham license back then:


Nonetheless, it ain't rocket science to make two icons come together on a map. In fact, only thing one needs in simplest terms is a lat/long and a device to manually plug it in to. As long as the units are correct one can be in good shape. Other permutations like to two dots on a screen with a navigation line is workable as long as one knows which was is North! I did that one time without a map and won't do it again. If I had seen the roads I would have
realized I could have driven on road to the recovery site and had a short walk to pick it up as opposed to fording streams and creeks in straight line fashion.

The APRS option above one can scroll from map to a navigation screen and back again. If walking, it will tell you how much time it will take you to get to the position! Talk about easy.

I hope an iPhone solution can be had for those that use the Apple devices. Kurt
Have you tried
NMEA Talker by Aman Enterprises Inc

They have a web video showing serial to Bluetooth to iPad replacing the iPad's gps location. They make the iPad think it's in different locations by feeding it simulated NMEA strings.

Yes, it wants to connect to their proprietary Bluetooth device. I see another that's very similar. It's possible they are using unique RSSID's or other device identifiers to discriminate their device from others. Without one to reverse engineer, I don't know how they are connecting.