# Eggfinder RX LCD PRO

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#### Wayco

##### Desert Rat Rocketeer
I've built a bunch of Eggtimer products, mostly Eggfinder TX units, and a few Eggfinder RX's, and some Eggtimer Quantums, Wifi switches, and a scattering of most of his other products. I'm always pleasantly surprised when they work. Not all of them did without some help from Cris. This thread is about one of those builds.
This build included a new Voice module, a GPS module and an older version (Rev B2) of the RX LCD. I managed to put all this stuff into the new Black Aero "Pro" case. I'm not gonna do a step by step build thread, but I will talk about some of the decisions I made and problems I had while building it.

First, I didn't add the bluetooth module (HC-06) because my old Android phone quit supporting bluetooth, and I prefer to input the GPS coordinates into the "Gaia GPS" mapping program, it has better satellite maps anyway, and is an app on my iPhone, which I prefer to the Android. There is a spot for the bluetooth module in the new Pro case, and I'm really impressed with the way everything fits in there. It's still the most challenging build I have done with Eggtimer products.

So, last week I warmed up by building another Eggfinder TX, tested it and everything worked fine. Then I got in the Voice module and built it and the GPS module. It had been quite a while since my last RX LCD build, but I still have two that are fully operational, one is in an earlier version of the Black Aero case, and another I didn't build, it was a gift from Cris back when I was a beta tester for his original Eggfinder.
Building Eggtimer products requires you to be able to understand the instructions and perform soldering skills at a fairly high level, at least in my opinion. My soldering skills were developed in the Marine corps, back in 1970 or so, and I really can't remember a lot about that time in my life, so skill wise, I'm probably somewhere between mediocre and average. After I had built a couple dozen Eggfinder transmitters, I started thinking I was good enough to shortcut some of the excellent instructions Cris has written, and that's when I started having problems. Now I'm back to following them exactly as they are written. Still occasionally have a problem, but it's usually my lack of understanding that causes it.

When I built the Voice module, one of the options was to mount the phono plug receptacle on the board or on the case, I decided that case mounting would make it easier to plug an earbud or phono cable to the PA system into it if it was accessible outside the case. I used a JST-XH plug to connect the module to the plug, so that I could separate the top of the case from the bottom, where all of the boards were mounted.
This is the bottom half of the Pro case, with the RX LCD board, Voice module and GPS module below it.

In the above pic, the voice module is partially under the GPS module, with a red JST connector over it, and the JST-XH plug above it connected to the phono plug mounted in the upper part of the case. At the bottom of the case (on the left) is a 3-way switch that turns the RX on or switches the unit to the charge position, allowing you to charge the battery without opening the case. On the right is the button that you use to program the RX and select different functions. Here is a picture of the other side of the case, where the molex plug and backlight switch are located:

I modified the case to hold the phono plug outlet and filed out a slot next to the backlight switch so I could run another set of wires out to program frequencies into the EF TX. On several occasions, I have had to change my operating frequency at a launch, and this allows me to do that easily.
I also modified the top of the case so I could see the lcd on the GPS module that indicates acquisition of GPS signal.
The position of this hole was marked on the inside of the case when it was printed.

I melted this hole with a soldering iron and covered it with a piece of scotch tape.

The main problem I had with this build was updating the RX with the latest software, and the details of that ordeal were worked out between Cris and Sharon, my wife. I think it had something to do with an old cable we were using and a driver that needed to be added to make everything work, but software and programming are NOT part of my skill set. Hopefully, Cris will add some more notes to his LCD Eggfinder flash update instructions to help others get past that problem.

The other issue I had was discovered when I did the final assembly. I had everything working, it was talking and receiving from the TX, getting good data, and I could reprogram my frequencies for both the RX and TX. When I put it all together, the backlight switch connectors broke the ground wire connection to the RX, which was located right below the backlight switch connections. I disconnected the switch and removed the wires to the backlight, now everything works but the backlight. I'm OK with that, but I'm sure that if I fiddled with it a bit more, I could re-attach that switch and make the backlight work too.

Hope this thread helps someone with their build, I'm really looking forward to using this at my next launch.

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#### kenstarr

##### Well-Known Member
What a timely thread! I just got to doing almost the same project. I glassed a large tube then I've spent the last two hours soldering. I have a pile of eggtimer products and I haven't assembled anything from Chris in a few years so I figured I'd start with the easier ones. Just finished the RX LCD and GPS add-on about 30 minutes ago. Thanks for the tips and tricks! On a side note, I'm going to pick up some reading glasses really soon...

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#### Jmhepworth

##### Well-Known Member
Good luck, Ken. I’ve had a run of good luck building Eggtimer products. When I brick one, it’s generally because I wasn’t being careful, either by installing something backward or by rushing a difficult soldering connection. Overall, I really like Eggtimer products. Cris provides excellent customer support.

#### KevinT

##### Active Member
Just finished building 3 of the LCDs in the black area pro cases. I did what you did and wired the phono jack with wires and attached the phono jack to the outside of the case, the top of the case in my version. With the phono jack hard soldered to the PCB there is no way to secure it to the case. The only additional thing I will be doing is mounting the GPS LED to the case. Right now I just have a hole in the case so I can see the status. I would like it more visible.

The only other issue I had was fitting the battery. It is the same one that is on the black aero video. With the voice module in place the battery does not fit well. I used wire cutters to trim the bottom section of the case to make some more room for the battery, and now the battery fits nicely.

All and all everything went together pretty well.

##### Member
Thanks for the write up. I have been planning on ordering this same setup and almost did when he had the sale for Christmas. So far I have built 2 quantum’s and a WiFi switch.

#### drgarymartinez

##### TRA 19960 - LEVEL 2
Isn’t there someone who will build them for me for a few? Please send me a link if there is, thanks.

#### ozwald

##### Well-Known Member
Cris can ship directly to Eric Hamilton or others for assembly for a minimum charge

#### Wayco

##### Desert Rat Rocketeer
Just finished building 3 of the LCDs in the black area pro cases. I did what you did and wired the phono jack with wires and attached the phono jack to the outside of the case, the top of the case in my version. With the phono jack hard soldered to the PCB there is no way to secure it to the case. The only additional thing I will be doing is mounting the GPS LED to the case. Right now I just have a hole in the case so I can see the status. I would like it more visible.

The only other issue I had was fitting the battery. It is the same one that is on the black aero video. With the voice module in place the battery does not fit well. I used wire cutters to trim the bottom section of the case to make some more room for the battery, and now the battery fits nicely.

All and all everything went together pretty well.
I ordered the 2S 2 ah Nano-Tech battery and also didn't like the way it fit. I use a similar Nano-Tech 1.3 ah 2S in my other (older) Black aero case, and had an extra in stock. It fits much better, leaving room for the voice module and pigtails. https://hobbyking.com/en_us/turnigy...D=85967&indexName=hbk_live_products_analytics
When Sharon and I are both making multiple high altitude flights in one day, I have been able to discharge the 1.3 ah battery, but kept a spare fully charged to replace it with. Of course, with the new Molex connector and three way switch, I could just recharge it in the case, but the larger battery does have some appeal. Thanks to Kevin for the tip on how to modify the case. I might be getting back in there and fiddle with the back light switch and battery enclosure.

Please feel free to post up any ideas or questions you have regarding this build.

#### John Kemker

##### Well-Known Member
Anybody have the STL files for the cases being displayed, here? Or, are they proprietary/have to buy them?

#### TSMILLER

##### Well-Known Member
I assembled mine today. I didn’t realize the case was marked for the GPS LED until I read this thread.
I like being able to see if the GPS chip was active, but did not like the open hole. I figured to get a clear button lens and install it. Looking on line I found several that would work. I then realized I had something on hand that would fit the bill perfectly.
Since the 7YO has a box of LEGOS weighing in the neighborhood of 1000lbs I knew I had a single clear round peg.
10 minutes of rooting I found one. I reamed the hole to .250, snapped the Lego in place 4 spot welds with the hot soldering iron and it is perfect. Clearly visible that the GPS is active.

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#### Wayco

##### Desert Rat Rocketeer
I'm really liking the LEGO modification, where do I get one of those? I did a search and came up with this:
clear LEGO part
Don't need 100 of these, but can't find them in smaller amounts.
Really glad I started this thread, all kinds of good ideas popping up here!

#### Jmhepworth

##### Well-Known Member
I'm really liking the LEGO modification, where do I get one of those? I did a search and came up with this:
clear LEGO part
Don't need 100 of these, but can't find them in smaller amounts.
Really glad I started this thread, all kinds of good ideas popping up here!
Wayne, You might want to try the nearest Lego Store. There’s one in Glendale and one in Chandler. They let you buy Lego bricks by the brick. They might have the clear ones.

Or try this. https://www.lego.com/en-us/page/sta...s.attributes.colourId&filters.i0.values.i0=40

#### Brian Ditmer

##### Well-Known Member
I'm really liking the LEGO modification, where do I get one of those? I did a search and came up with this:
clear LEGO part
Don't need 100 of these, but can't find them in smaller amounts.
Really glad I started this thread, all kinds of good ideas popping up here!
I assembled mine today. I didn’t realize the case was marked for the GPS LCD until I read this thread.
I like being able to see if the GPS chip was active, but did not like the open hole. I figured to get a clear button lens and install it. Looking on line I found several that would work. I then realized I had something on hand that would fit the bill perfectly.
Since the 7YO has a box of LEGOS weighing in the neighborhood of 1000lbs I knew I had a single clear round peg.
10 minutes of rooting I found one. I reamed the hole to .250, snapped the Lego in place 4 spot welds with the hot soldering iron and it is perfect. Clearly visible that the GPS is active.View attachment 497612
is that a new style of case? Or something you printed? I got the TX/RX set and it came with a black box

#### TSMILLER

##### Well-Known Member
is that a new style of case? Or something you printed? I got the TX/RX set and it came with a black box
Blackaero, he’s been making them for a few years, this is the latest.

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#### John Kemker

##### Well-Known Member
Blackaero, he’s been making them for a few years, this is the latest incarnatio.
Thanks! I might just have to replace my previous BlackAero case with one of those!

#### Wayco

##### Desert Rat Rocketeer
Wayne, You might want to try the nearest Lego Store. There’s one in Glendale and one in Chandler. They let you buy Lego bricks by the brick. They might have the clear ones.

Or try this. https://www.lego.com/en-us/page/sta...s.attributes.colourId&filters.i0.values.i0=40

Thanks Joe, obviously this is an area that I have very little knowledge about. I tried the link, there are 16 clear thingy's, none of which look like they would work.
There is a store nearby, called "Bricks & Minifigs", might be my next move.
Never stepped on a LEGO brick, didn't even know that they have stores specifically for this stuff.

#### TSMILLER

##### Well-Known Member
This is the part I used.
I looked for it in the Lego store (on line) and didn’t find a transparent one listed. It is included in more than 100 kits, so it has to be available somewhere.
Bricks and minifigs would be a good staring place.

#### Wayco

##### Desert Rat Rocketeer
Thanks guys!
Brick owl lists one through AZ Bricksource for just 1 cent, minimum order $3, shipping$3.80. I'm thinking that "Brick's & Minifigs" might be my first stop.
Now that we have derailed another of my threads.....
Maybe someone should start another thread about using LEGO's in model rocketry.

But I do appreciate all the help.

#### kjs

##### Well-Known Member
But I do appreciate all the help.
Funny that Wayne talked to Sharon and Sharon knows my wife Tracy has built some of the larger Lego projects. Sharon contacts us, Tracy roots around in her spare parts bag - and now there will be clear and amber lego 'lenses' going out with the mail on Monday... It takes a village...

#### kenstarr

##### Well-Known Member
Got mine all ready for final assembly. Upon powering on, everything seems to work fine except when it comes to getting a GPS fix. I let it run about 30 minutes outside and it was still waiting. I've yet to inspect extremely closely all my soldering. Well see. I've got a stellar track record on eggtimer products up to now. I may just pick up another GPS. I feel like having 2 of things makes troubleshooting easier... Assuming one doesn't screw up the same thing twice!

#### Wayco

##### Desert Rat Rocketeer
Did you match the frequency on the RX to your TX. It is set at 915 Mhz. I usually make this mistake at first....

Big thank you to Kevin and Tracy!

kjs

#### kenstarr

##### Well-Known Member
Oh heavens. This is hilariously embarrassing. I failed to properly read and understand the instructions. As a result, I was under the impression the LCD receiver would pop up with some GPS coordinates without the transmitter. I see now everything is working as it should and until I get the transmitter soldered up and powered on I can't further test. Thanks.

#### kenstarr

##### Well-Known Member

Well, I really like the Lego LED combo. So far so good except the molex connector really kicked my butt and I gave up on that part. Thus far this project has been a fantastic learning opportunity and has stretched my abilities.

#### cerving

##### Owner, Eggtimer Rocketry
I haven't put the Molex connector on mine either, but that's mainly because I don't need it. My Turnigy P606 charger only uses the balance connector, so I just have the battery's balance connector hanging out the side. It makes wiring a lot easier, too.

#### TSMILLER

##### Well-Known Member
View attachment 497957
Well, I really like the Lego LED combo. So far so good except the molex connector really kicked my butt and I gave up on that part. Thus far this project has been a fantastic learning opportunity and has stretched my abilities.
That molex was the same issue with mine. I couldn’t get a good wire end that was acceptable to my satisfaction. Workable, not pretty, but once it’s hidden….if it works I guess it’s ok!
I also think with the “Lego Lens“ in place the LED visibility is greatly enhanced.

#### pbahorich

##### Well-Known Member
The Molex is giving me trouble as well.
I haven't had issues crimping pins and sockets for D38999 connectors on aircraft (I'm an aerospace engineer) or terminal lugs for other applications. And I've built 9 boards from Eggtimer so far and they've all worked at first power up.

But I haven't worked with Molex before and these small ones that came with the v3 pro are giving me some issues. I bought a crimping tool on Amazon (IWS-1424A do not use) that was advertised to work with Molex, but it's too thick and the pin retainers get deformed when I use it. I could have bought the $457 Molex crimp tool to build my$35 case, but I guess I'm too cheap: Crimp Tool, Hand, Molex Micro-Fit 3.0 43030, 43031, 44372 & 45773 30-20AWG Terminals - Audio Video Cables And Connectors - Amazon.com

Apparently, Molex is a brand name which provides many different styles of connectors. After some research on the Molex website, it looks like the Micro-fit 3.0 type Molex connector is provided with v3 Pro kit. 987650-5984.pdf (molex.com)

The 4302006XX is used on the case side (which is compatible with 43031 series male pins) and the 4302506XX (which is compatible with 43030 series "female pins" aka sockets) is used on the charger cable side (XX is material type which shouldn't matter for our application, 08,10, 00). Note that the Black Aero video shows the male pins are used on the cable side, which is opposite.

Anyway, I've ordered this crimper which is supposed to work with the Micro-fit series:
IWISS SN-28B Dupont Terminal Ratchet Crimper 0.1-1.0mm ²(AWG28-18) for 2.54mm 3.96mm KF2510 connector - - Amazon.com

I'll let you know how it turns out.