EggFinder LCD GPS add-on

[ksaves2]

Shots of the GPS add-on on two different built LCD's: (Click for larger pics)


From the upper left to right: The stock case side by side with my Yellow Black Aero case. The GPS modules for navigation are on top and are secured
with double sided servo tape..

Next is the yellow Black Aero with the back off. You can see the HC-05 B/T module I used servo taped to the backside. These are v1 LCD boards so I had to do the wire soldering shown in Cris' instructions.

Next is the black stock case with the front off. I soldered a terminal block to the backside of the GPS module board and used the wire socket connector
Cris provided and cut off the socket/plugs on one end. I plugged the other into the terminals I soldered on the bottom side of the GPS board. Used a dremel router to cut out an elongated hole. It didn't show up so well in the pic. The motherboard in this case is mounted on nylon spacers with screws and nuts and the LCD board is mounted into the face cover. You can see a 4-40 socket head screw on the lower right on the motherboard. The wire interconnect was bought off of Ebay.

Fourth pic from the left is another shot of the case opened. I have mixed feelings about the way I did this mounting in the stock case upright but I like it more and more.

Fifth from the left is both side by side upright. One can appreciate the mounting of the GPS board on servo tape. I want the GPS to have a clean shot of the sky and not be "locked up" inside some stupid case!:wink: Since we rocket folks like fillets, I used a single substantial J&B fillet to keep the
GPS antenna from being "jostled off" the base. Don't ask me how I know how/why to do this.

Sixth from left is an overhead and I just so happened to catch both yellow LED's lighting up. I had both units tuned to an EF mini out in the cold
yard.

The next three shots are side by sides of both units "tracking" the Mini out in the yard with the LCD light on and off.

Bottom left picture is the yellow Black Arrow case with an overhead of the GPS board.

So I open it up for other and perhaps better ideas. Kurt

 

[Eric]

What did you glue the GPS antenna to the pcb? And why only in one side? And do you expect a lot of strain on the ground unit?

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[OverTheTop]

I want the GPS to have a clean shot of the sky and not be "locked up" inside some stupid case!

I suspect you are being a little paranoid keeping this in the open. The GPS units are so good these days with their multiple correlators and crazy smart algorithms they achieve lock in really challenging situations. I would be more concerned about moisture or other contamination on the PCB.

 

[Voyager1]

I suspect you are being a little paranoid keeping this in the open. The GPS units are so good these days with their multiple correlators and crazy smart algorithms they achieve lock in really challenging situations. I would be more concerned about moisture or other contamination on the PCB.

I agree! I would be very concerned about damage to the GPS module by dust, moisture, mechanical damage, etc, with these handheld units. Remember, your rocket GPS unit works just fine from inside the body tube.

 

[tim cubbedge]

I want the GPS to have a clean shot of the sky and not be "locked up" inside some stupid case!

Dude, I drive around with it in my car in a case & it works fine. The module in my rocket is enclosed in FG & works fine.

 

[ksaves2]

What did you glue the GPS antenna to the pcb? And why only in one side? And do you expect a lot of strain on the ground unit?

Sent from my VS988 using Tapatalk

I use a red double-sided servo tape to secure the board assembly to the black or yellow case. The GPS I followed Cris'
soldering instructions and that grey fillet bead is jes' good ol' J&B Weld. Kurt

 

[ksaves2]

I suspect you are being a little paranoid keeping this in the open. The GPS units are so good these days with their multiple correlators and crazy smart algorithms they achieve lock in really challenging situations. I would be more concerned about moisture or other contamination on the PCB.

You are correct but I don't plan to fly in storms. I want to see the yellow LED direct. There's always a large zip lock bag one can bring along for safety against rain. Kurt

 

[ksaves2]

I agree! I would be very concerned about damage to the GPS module by dust, moisture, mechanical damage, etc, with these handheld units. Remember, your rocket GPS unit works just fine from inside the body tube.

Dust? That's a good one. Drop it in a body of water and it's likely a goner no matter where it's mounted.
Drop the case, either one, and something is going to break inside. If the case hits on the bottom, the GPS will
likely be unharmed but something else inside the case will break. Don't ask me how I know. Kurt

 

[ksaves2]

What did you glue the GPS antenna to the pcb? And why only in one side? And do you expect a lot of strain on the ground unit?

Sent from my VS988 using Tapatalk

Oooops, forgot to answer for why on one side. The mounting of the GPS on the board is asymmetric so one side has plenty of room/surface area for a substantial fillet. I think since this arrangement is not flying "in" a rocket, one fillet on the side that has the most surface area is enough for security. People will see what I mean when they get the upgrade if they can't appreciate it in my humble photos. Kurt

 

[Eric]

Oooops, forgot to answer for why on one side. The mounting of the GPS on the board is asymmetric so one side has plenty of room/surface area for a substantial fillet. I think since this arrangement is not flying "in" a rocket, one fillet on the side that has the most surface area is enough for security. People will see what I mean when they get the upgrade if they can't appreciate it in my humble photos. Kurt

Yes. I can see the offset. Makes sense to me. I always thought JB-weld was metallic and would effect the GPS antenna. But I just read that its not.

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[ksaves2]

Yes. I can see the offset. Makes sense to me. I always thought JB-weld was metallic and would effect the GPS antenna. But I just read that its not.

Good point but I always try to look up the conductivity of whatever glue I'm using if I want it to act as an insulator. There is conductive stuff out there if one wants it and looks for it. Kurt

 

[Crazyrocket]

Interesting using the JB weld. The instructions for the mini assembly specifically recommend NOT using it. Not sure if it will really make any difference given that it is on the base unit and not the rocket.

 

[OverTheTop]

Yes. I can see the offset. Makes sense to me. I always thought JB-weld was metallic and would effect the GPS antenna.

I have read that the ceramic GPS antenna is stuck onto the GPS PCB by conductive tape anyway. If the fillet is small it is likely to be of little consequence to antenna performance.

 

[Eric]

It works just like Cris said it would... Really happy with ground testing... Snow Ranch test this weekend.

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[ksaves2]

I have read that the ceramic GPS antenna is stuck onto the GPS PCB by conductive tape anyway. If the fillet is small it is likely to be of little consequence.

No it's not. Break yours off and see if you can fix it. Cris reports he couldn't come up with a fix for it. For in flight use, fillets on both sides will add a degree of robustness for jostling around on a normal landing.
For ground use a large single fillet will likely help fixate the antenna for minor trauma. I dropped a newly built EF 2 feet and the "unfilleted" antenna snapped off the base. The base of the EF hit the floor. That's
how I acquired an EF with an outboard Ublox chipset. I salvaged the busted one to do something different.

In flight units I agree, two fillets would likely be better than one. You also need to keep in mind there is a space on two sides of the base you don't want to slop solder or epoxy inside.

A ballistic hit and the unit is going to die no matter what. At least you have a better chance finding the remains than RDF. Kurt

 

[patelldp]

It works just like Cris said it would... Really happy with ground testing... Snow Ranch test this weekend.View attachment 333207

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Mind if I ask where you got the stubby antenna?

 

[Eric]

Mind if I ask where you got the stubby antenna?

From Cris. With egg finder mini purchase. It is an upgrade option.

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[OverTheTop]

No it's not. Break yours off and see if you can fix it.

My comment on it being of little consequence was in relation to the RF performance. Mechanically it will be an improvement.

 

[cerving]

I have read that the ceramic GPS antenna is stuck onto the GPS PCB by conductive tape anyway. If the fillet is small it is likely to be of little consequence to antenna performance.

Even if if the fillet is large it won't matter... it's looking at the TOP of the antenna, not the sides, so the fillet has no effect on antenna performance. It has a great deal of effect on durability, however...

 

[ksaves2]

From Cris. With egg finder mini purchase. It is an upgrade option.

Sent from my VS988 using Tapatalk

Mine came with it stock. Kurt

 

[ksaves2]

My comment on it being of little consequence was in relation to the RF performance. Mechanically it will be an improvement.

My sincere apologies then. Like Cris points out it shouldn't have an effect as long as the fillet is along the side of the antenna and not slathered all over the top.

That said, I was messing with some 3DR radios with Ublox chipsets and using the UCenter program to monitor the incoming GPS signals from the radio sitting next to my computer indoors.

By golly I could get a multi-satellite lock and this chipset could use both the U.S GPS and Russian Glonass together. If I put my hand over the GPS antenna, I could see a little attenuation with just my hand over the antenna of the Ublox GPS.
The signal was certainly very usable but there was a slight reproducible drop and recovery with my hand.

I don't think 3DR is too terribly viable and a poster reported they had success with it. I believe the radios need a lock at both ends to reliably transfer data. This cuts down on range. There is a setting to use the base station as "receive" only but I haven't
tried it yet as far as testing for range improvement.

The other thing is the Chinese suppliers lie about the power output. I've seen one reliable report that a user saw 270mW output on an alleged 500mW rig. It is said it takes a certain power metering setup to reliably measure a spread spectrum radio output.
My take is I had fun playing with it but do not count on it to be an el cheapo tracking means.

Stick to what's commercially available. I may get a chance to flight test but I'd do it in a disposable rocket. Kurt

 

[Eric]

Mine came with it stock. Kurt

You are correct. The mini did come with the 1/4 wave. It was an option on the TRS.

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[BradMilkomeda]

O, is that blue and white cable labeled “reset sw” from a computer case?

I just ordered all this stuff from the sale this weekend. It going to take a while to solder it all up, test it, and figure out how it works.

Thanks for sharing your set up!

 

[Voyager1]

Dust? That's a good one. Drop it in a body of water and it's likely a goner no matter where it's mounted.
Drop the case, either one, and something is going to break inside. If the case hits on the bottom, the GPS will
likely be unharmed but something else inside the case will break. Don't ask me how I know. Kurt

I was actually considering your best interests with regard to protecting your investment, that is all! The examples you use are rather extreme and not what I was referring to. There is always a risk with exposed electronics. I say this from 40 years in electronics engineering.

Cheers

 

[BLKKROW]

Just a heads up for those who are interested, I am currently redesigning the LCD case to accommodate the GPS add on and the Bluetooth option.

This plus a lot more will be available soon.

 

[ksaves2]

O, is that blue and white cable labeled “reset sw” from a computer case?

I just ordered all this stuff from the sale this weekend. It going to take a while to solder it all up, test it, and figure out how it works.

Thanks for sharing your set up!

Yup, I had some friends with a local computer concern and they let me tear the wires out of cases that were going to the recyclers. Kurt

 

[ksaves2]

I was actually considering your best interests with regard to protecting your investment, that is all! The examples you use are rather extreme and not what I was referring to. There is always a risk with exposed electronics. I say this from 40 years in electronics engineering.

Cheers

That's a valid response. I made the add on so I could slice it off with a hobby knife and install a replacement easily.
Also my units are probably not going to be exposed to the elements for long periods of time. Kurt

 

[rharshberger]

If anyone is having issues updating thier LCD software, make sure to re-boot Windows after installing WinAvr the Prolific driver, or the LCD will fail to sync and not update.

 

[CORZERO]

You know, I became a member of this site just a couple of years ago after having renewed my childhood interest in Estes kits by building a Black Brant II I found on Ebay. Through research on the site and in general, there wasn't much to speak of in terms of inexpensive, commercially available compact tracking systems, and now there seems to an solution for just about every experience level and bank account size. It's been interesting to see the evolution and development of this stuff (and application specific electronics in general) within the hobby. It's nice to see vendors and the commercial folks interacting with fellow hobbyists so closely as they develop their products, as well as individual member contributions through garage work bench experimentation and development. All lending nicely to the sentiment of small community comradeship.

 

[PiperCPO]

Here here Corzero! Being a BAR as well and having gone through several hobbies, overall I can say that the involvement of the manufacturers and interface with those that buy and fly their products is very impressive. I also realize that the majority of them are Rocket Junkies like the rest of us. Which is a big part of it.

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