The Eggfinder - A Low-Cost GPS/RF Tracking System

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Kurt, didn't you find a magnetic base omni-directional antenna that had about 25 db of gain? I thought you posted a link to it.
I have the 5 db rubber duckie antenna on both my transmitters, and use the same on the RX unit. The unit Cris gave me has the same. I have two receivers, one linked by bluetooth to my Android, and the second one has the LCD screen. I just got another HC-06 but am wondering if I should use both in close proximity to each other. The second unit could pair up with my laptop if they don't interfere with each other. I could use the Android to hunt down the rocket, and keep the LCD receiver as a base station in the truck with the laptop.

No,

Not 25db gain. It's a Chinese mag mount which btw doesn't have a strong enough magnet to drive around with.
It does seem to have decent range over the ground though. https://www.ebay.com/itm/HIGH-GAIN-..._Mobile_Broadband_Devices&hash=item233917e921

They say 9Dbi gain but take Chinese specs with a grain of salt. I believe this is more suited for a laptop base station
for flight recording. Having the antenna mounted to the roof of a vehicle might give it a little edge as the rocket descends closer to the ground. A patch antenna would take someone to point it at the rocket so if this or any
other Omni directional antenna gives good performance, would eliminate that task.

I plan to do exactly as you are doing and have to build a second B/T enabled receiver. Once the two devices are paired (say computer and EF receiver) one should be able to pair second receiver to an Android device nearby.

I unfortunately live in a lousy geographical area for launching high and am limited in being able to flight test when I want to. I look forward to other folks reports as I think Cris EF's would be just as good as the currently available
APRS trackers. The cost difference is astounding.

I believe someone reported flying to 13k with a duck on the transmitter and a wire on the receiver. That's impressive if true.

Kurt
 
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I believe someone reported flying to 13k with a duck on the transmitter and a wire on the receiver. That's impressive if true.
Close. :)

Raven reported 14881', wire on the Tx and duck on the Rx. I posted a pic in the liftoff gallery thread if you're interested. I should point out that I don't know if it had GPS lock all the way up, or if I received all packets. When I was trying to track it on the way down, it said max altitude was 4580m(~15026'), so it seems to have regained lock quickly if it lost it (launch site was at 266m/825'), and the discrepancy points to a brief loss of either data or lock. Off topic for this thread, I guess, but does anyone know how to get the Rocket Locator log off Android for external analysis?

Also, I also bought a cheap patch antenna but didn't use it. In hindsight I don't think I ever will. I lost sight of my rocket and would have had no idea where to point the patch, and possibly could have made things worse by pointing in the wrong direction. My gut feel going forward is a high gain omni is most likely safest for out of sight flights.
 
I have two receivers, one linked by bluetooth to my Android, and the second one has the LCD screen. I just got another HC-06 but am wondering if I should use both in close proximity to each other.

Has anyone used the HC-06 with the LCD receiver yet?
 
Has anyone used the HC-06 with the LCD receiver yet?

Just got mine in the mail yesterday, so I guess I will be the first. Hoping to pair it with my laptop, but not sure how that will go. Also not sure what program I can use to access the data if it does come in via bluetooth....

Thanks Kurt, I just ordered that antenna to use with the LCD RX that Cris gave me at ROCstock. Hoping to get all this stuff working together for some of the higher flights I have planned later this year.
I have an Eggfinder in the N/C of a 54mm MD Blackhawk that sims to 17,000 ft. on an L935 Imax, and just bought a MD CF 75mm Mongoose from Gary Tortora with Proline Rocketry. It could bust 20k with the right motor, and has a profusion N/C which will let me use the Eggfinder without loosing signal in the carbon fiber body.

Matthew has inspired me with his flight to 15,000 ft. Who knows what we might get with the right antennas....

As most of you know, I'm not the most "teckie" guy here, and any help with software/hardware suggestions will be much appreciated.
 
I certainly understand the need to keep the antenna away from all-thread. If the eBay doesn't have any (i.e. it's integrated into a 3D-printed nose cone) is it ok to put an altimeter right next to thee eggfinder circuit board?
 
On my Eggfinder build, I installed the RP-SMA connector to use a rubber duck antenna.
Is there a way to retrofit the wire whip antenna so that I could screw it onto the RP-SMA connector if I want to change back and forth between antenna types?
 
You can get a RP-SMA MALE connector (inside threads, socket in the middle) and solder an 80mm piece of 1/32" brass wire to the socket pin. I've done that, it works exactly the same as the wire antenna.
 
Whats the word on interference with the antenna being near other altimeters or batteries?


TA
 
Whats the word on interference with the antenna being near other altimeters or batteries?


TA

One should avoid having the antenna paralleling metal all-thread or batteries due to attenuation of range. I believe putting the battery on the opposite side
from the EggFinder is acceptable. Just keep the antenna in free space and avoid metallic paint finishes. Non-metallic paint is fine. See also this informative post by John Coker. He knows more than me on the subject: https://www.rocketryforum.com/showt...l-newb-with-no-smartphone&p=734191#post734191

With really tight space, I had a wire antenna poke through a form fit hole through the forward bulkhead into a main chute bay. Wrapped the cardboard tube that AT first fire igniters come in with duct tape and used clay to secure the tube to the bulkhead. It acted as a stiff conduit for the antenna so it didn't get squished or flammed by the charge. Worked fine for a 6500' flight that landed .85mi away with a low powered BeelineGPS tracker. Alternatively, one could get a cable extender like this:

https://www.ebay.com/itm/cable-RP-S...0097&clkid=8453447401075933979&_qi=RTM1562569

In that way, one could put an antenna on the bulkhead. Could put some non-metallic flame protection around it and all should be good. I have a 3" Wildman rocket I stretched with a longer upper bay because I like longneck rockets. Had the BeelingGPS antenna project into the upper main chute bay from the ebay with the MAWD riding below. The entire rocket was painted with Dutch Boy rattle can metallic. Great reception at short range but ol' stupidhead here didn't do even a 2 block range test. First flight was an L1400 to 10k'. Received one lousy packet from 8000'. Fortunately, the rocket landed within sight. Was the stupid metallic paint! Launched a second rocket that day with a tracker that was metallic painted and same thing. Lesson learned.
Soooooo, I didn't want to strip the paint from the rocket but I was very lucky that my 10" long ebay/sled was completely symmetric. I just switched the tracker to ride aft with a connector like the one above and put the MAWD forward. The bulkhead antenna comes out the aft bulkhead so once the apogee charge blows the rocket apart, the antenna will be in free space and packets should come in. Kurt
 
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ksaves2 is correct, you may mount the battery on the back side of the sled if it's mounted opposite the Eggfinder PC board, NOT the antenna. Keep the antenna clear of metallic obstructions if at all possible. Again, this isn't an Eggfinder thing... it goes for just about any RF tracker, including beacons. For best range, you want the radio waves to have as clear a path as possible to your receiver, and metal near the antenna can cause attenuation and/or reflections that will affect your range.
 
ksaves2 is correct, you may mount the battery on the back side of the sled if it's mounted opposite the Eggfinder PC board, NOT the antenna. Keep the antenna clear of metallic obstructions if at all possible. Again, this isn't an Eggfinder thing... it goes for just about any RF tracker, including beacons. For best range, you want the radio waves to have as clear a path as possible to your receiver, and metal near the antenna can cause attenuation and/or reflections that will affect your range.

OK thanks, I guess I need to rethink some battery placement.


TA
 
Well after a great week vacation with the family, I finally was able to finish my Eggfinder LCD. The red button is the the programming button and the small hole you see to the right is a small low profile reset button, and a power switch on the top. Its a nice unit I cant wait to get out and put it to a real flight test.


TA

20140720_133711.jpg


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I use a 2c, 7.4v 300mah Lipo Pack.
https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=28646

I'm pretty sure I've run it for a least four hours as a test.

All very interesting and I will probably be buying one very soon. Searching for hours at LDRS in knee and chest high grass is not my idea of fun!

New to the Lipo batteries - thanks to the specific link. May be an easy question, but can you provide a link to the proper device to charge the battery?

Thanks in advance.

Tom
 
All very interesting and I will probably be buying one very soon. Searching for hours at LDRS in knee and chest high grass is not my idea of fun!

New to the Lipo batteries - thanks to the specific link. May be an easy question, but can you provide a link to the proper device to charge the battery?

Thanks in advance.

Tom

Yes I Can!
https://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18066

And you'll need this too.
https://www.hobbyking.com/hobbyking/store/__33326__Charging_harness_USA_Warehouse_.html
 
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I noticed that the charger states - "Note: Power supply not included." Really?

Oh yea. I had forgotten about that. I work in IT and we have plenty of 12v wall wart power supplies laying around. I just snagged one of them, cut off the end and spliced it to the cable that came with the charger.
 
I noticed that the charger states - "Note: Power supply not included." Really?

That is correct, you can use the supplied alligator clips to attach it to a 12 vdc battery, or buy a small power supply (inverter) that converts 120 vac to 12 vdc.

https://www.hobbyking.com/hobbyking...ng_105W_15V_7A_Switching_DC_Power_Supply.html

https://www.amazon.com/dp/B007ME2HMQ/?tag=skimlinks_replacement-20

Depending on your power usage, that second one from Amazon might not be sufficient.
 
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Also dig through your old electronics bin. Look at the output rating on some of your old cell phone charges, portable CD player, etc....
 
Anyone have links to a couple rubber ducky antennas? I'm looking on amazon and can't seem to find much. I'm new in this area.
 
OK. I have downloaded all of the drivers, (downloaded from Eggtimer rocketry's website), and I still cannot get my Rx to connect to Mapsphere. It does not recognize the device. Any help?
 
OK. I have downloaded all of the drivers, (downloaded from Eggtimer rocketry's website), and I still cannot get my Rx to connect to Mapsphere. It does not recognize the device. Any help?

It worked fine on my laptop and I'm running windows 7. Maybe it's time for a new laptop... Didn't you also have problems with your RRC3 and connecting it to our laptop? Also I think that you need to have the RX and TX connected to get it up on mapsphere but I'm not sure.


Edit: I cannot connect my RX to mapsphere by itself.
 
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What COM port did it assign to the USB-Serial cable? I recommend that you go into Device Manager and change it to a low number (COM1-COM4) from the "Advanced" button under Ports/Properties/Port Settings. Some software does not like higher port numbers, I don't know if MapSphere is one of them because I've always used low numbered ports on basic principle.

OK. I have downloaded all of the drivers, (downloaded from Eggtimer rocketry's website), and I still cannot get my Rx to connect to Mapsphere. It does not recognize the device. Any help?
 
Check the driver version number in Device Manager, it should be 3.3.2.102. If it's later (and I suspect that it is...) uninstall the device including the driver, reinstall the Vista driver, then plug in the cable again. It should pick up a low COM port, but if you check the driver version in Device Manager it may still have the high (incorrect) version. If it does, tell it to revert to the previous version, and it should work. I just talked through this with someone else on the phone, so I'm pretty confident that it will work.

Stupid Windows tricks... :)

Windows 8.1 running Windows 7 compatibility mode.
 
Check the driver version number in Device Manager, it should be 3.3.2.102. If it's later (and I suspect that it is...) uninstall the device including the driver, reinstall the Vista driver, then plug in the cable again. It should pick up a low COM port, but if you check the driver version in Device Manager it may still have the high (incorrect) version. If it does, tell it to revert to the previous version, and it should work. I just talked through this with someone else on the phone, so I'm pretty confident that it will work.

Stupid Windows tricks... :)


Ehhh... it actually didn't work. Correct driver, same error. :p
 
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