Eggtimer TRS and Eggfinder LCD Build Thread

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My skills also improve greatly, if I did another I'm confident I could do it in half the time. This was my first SMD. Lots and of fun, I'm glad it's finished though I'm pretty tired at this point.

The more Eggtimers you build the easier they get. Also, the TRS is the most detailed build. With a TRS under your belt you could build a Quark in a hour or so.
 
The instructions provided by the manufacturer are fantastic. They are specially handcrafted so the neophyte solderer will have the best chance of success.

+100 Agreed! Eggtimer Instructions are top notch. :cool:
 
Ok I just finished the LCD Receiver, this was a walk in the park compared to the TRS, almost disappointingly easy 😀😀😀😀.

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Started with the case as recommended, changed it slightly from the plans....hope I don't regret that later.

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The case was harder to cut than I expected. I ended up using a Dremel then detailed with a razor knife.

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Ok I'm not quite finished. I was not sure where to mount the button switch? Does it go in the SW or Button holes. I must have newer model than the online pictures as it appears to only show button. I'm guessing button but waiting on verification from Chris..... building on though as this is easy to access later.

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Getting ready for final assembly and testing as soon as I get the switch mounted.

Again awesome instruction and much easier to assemble than the TRS😀😀
 
Ok I'm not quite finished. I was not sure where to mount the button switch? Does it go in the SW or Button holes. I must have newer model than the online pictures as it appears to only show button. I'm guessing button but waiting on verification from Chris..... building on though as this is easy to access later.



As I recall, SW is for power, button is for programming. You can also add a switch for the backlight. There are a few old threads that show how people mounted these switches and buttons on the case. Here is one example:

https://www.rocketryforum.com/showt...-for-Eggtimer-Eggfinder&p=1473094#post1473094
 
The SW and Button are the same thing. One is for mounting the switch to the pbc, the other is to connect a plug (or soldering wires directly) so that you can wire it to an externally mounted switch. Not sure which is intended for which purpose, but electrically they perform the same function (which you can see from the wire trace).Cris modified this as the new firmware added new functionality to the button.



You can see the traces here wiring the button and SW together.
 
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Looks to me like button is still ment to be soldered into the button area while the SW is for wiring the externally accessible switch.

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SpaceManMat

Thank you, it is rather obvious once you point it out. Not sure why I missed that.
 
Looks to me like button is still ment to be soldered into the button area while the SW is for wiring the externally accessible switch.

You may want to get a push button to mount on the outside of your box with your power switch so you don't have to open the box everything you want to program. If you look at the pictures I posted a link to in Post #36 you will see two black rocker switches and red push button switch on the outside of the box. The rocker switches are power and backlight. The red button is the push button. After you put your rocket on the rail you have to use the push button to get the TRS into flight mode. I didn't want to have to open the box up on the flight line to push the button.
 
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You may want to get a push button to mount on the outside of your box with your power switch so you don't have to open the box everything you want to program. If you look at the pictures I posted a link to in Post #36 you will see two black rocker switches and red push button switch on the outside of the box. The rocker switches are power and backlight. The red button is the push button. After you put your rocket on the rail you have to use the push button to get the TRS into flight mode. I didn't want to have to open the box up on the flight line to push the button.

By golly you need to do that for sure! The red push button on the post I did earlier is just that. The thing I failed to mention earlier is doing the box stock and not vertical with a separate ribbon cable like I show, one is able to get at that all important
serial terminal on the back side of the board. Since the LCD is mounted directly to the lid and the mainboard is plugged into it, just unscrew the lid, flip it over and easy to do programming and plug in the B/T module. Kurt
 
The button is also used to recall the last coordinates in the event you power down the LCD. So even if you don't have a TRS you still want it use it without opening the lid.
 
Here is the finished product!

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I assembled everything and then turned on the TRS and then the LCD Receiver, they synced within a few minutes and then produced coordinates. I hope it works that easy in the field.

I also added the config and back light switches.

Once I finished putting it together, I hooked a 9v up to the TRS, turned on the receiver, grabbed the dog and went for a walk. I know my neighbors if they saw or heard had further confirmation that I must be crazy as I carried a beeping cardboard box at 11:00pm while I walked the dog. When I was about a 1/4 mile away I called home and asked the wife to record the coordinates. When I got home I verified the location and it was easily within a few feet.

Up next AV Bay, the rest of the rocket is complete, less recovery.

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Here is a quick peek, I've been debating about doing a build thread but my pictures are not great and there are so many really nice threads already out there.

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I'm also gonna post the cost to build this rocket. I got everything on sale but I still think I will have close to a grand in this rocket counting the Hakko Soldering station but not counting the RRC2, glue, paint, sand paper, etc.... that I already had on hand.
 

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Did you put a momentary switch on the front panel so you can program the LCD. I hope that button on #38 was a dry fit and not soldered in or you have an external switch in parallel to it. Kinda useless inside the box.

Did you get a B/T module and get it wired into the back? Get a module with a cable so you can plug it in and out as needed in the remote event you have to update the firmware. Plus you can use that serial socket
to program the frequency with a v2 EggFinder tracker if you would like to get one of those in the future.

Now if you had an Android device with the LCD paired to it, your wife could have "seen" were you were directly on a Google map with a GPS Rocket Locator. No futzing with typing in coordinates. Just live mapping.

Where again is the antenna going to reside with the TRS? If you are going to have it poke through a hole in that forward bulkhead into the main chute bay, put a layer of electricians tape around the cardboard tube an AT wired igniter
comes in to stent the wire antenna so it doesn't get squished by the recovery laundry.

If you are going to have it parallel the two all-threads in the ebay, be aware that's very bad ju ju. Very bad. Rocket fly sight unseen and rocket say, "No positions from me mon!" Very bad feeling to you. Me not want that.
Me want see you have fun flight, know where to go, walk right up to rocket! Good feelings! Kurt:wink:

https://www.rocketryforum.com/showt...-for-Eggtimer-Eggfinder&p=1394589#post1394589

Alternative case: https://www.blackaero.com/products/eggfinder-lcd-case
This battery fits in the above case: https://www.hobbyking.com/hobbyking..._20_40C_Lipo_Receiver_Pack_AR_Warehouse_.html
 
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Bravo! That looks great! And 10 days ahead of schedule! For many, design and construction is where the satisfaction lies in this hobby. Don't worry about the cost. I have over a grand into my 2.6" 38mm L2 project and it is still strewn about in pieces. Tools, materials, equipment, parts, failures, tangential purchases from ideas spawned by the build, etc.. Lots of first-time purchases for stuff/tools I never had before getting into this. A hundred here, a hundred there. It will even out in the end. There are many other hobbies out there which are WAY more expensive!
 
Bravo! That looks great! And 10 days ahead of schedule! For many, design and construction is where the satisfaction lies in this hobby. Don't worry about the cost. I have over a grand into my 2.6" 38mm L2 project and it is still strewn about in pieces. Tools, materials, equipment, parts, failures, tangential purchases from ideas spawned by the build, etc.. Lots of first-time purchases for stuff/tools I never had before getting into this. A hundred here, a hundred there. It will even out in the end. There are many other hobbies out there which are WAY more expensive!

Ahhhhhhhh, Once you find you get certain tools and stock a few consumables on hand it generally becomes financially easier.:) Kurt
 
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Initial test was good to go. Now need to solder CPU and other remaining items. Excited!

Had a question though. The TRS assembly guide talks about suitable voltage input ranges, but the LCD does only mentions using either the 4 cell AA, or a 2S lipo. Can one also use a 3S lipo or is that too much for the power system to handle. I just happen to have a 3S that I can use for the moment.


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Stick with the 4 AA for testing and get yourself a 2S lipo the largest capacity you can fit in your case. That will give you a long run time on your LCD so you can fly multiple rockets with multiple EggFinders/TRS units. You'll like the TRS as
you get the live indication that the deployment channels were activated. That baro altitude is a nice touch. If you want to maximize the recovery of the position packets, you can consider a patch antenna. Not necessary but does increase the success of decoding positions. Without a patch antenna, you'll generally get more reliable decoding after the main comes out and the descent velocity decreases. Hence I have a tendency to blow the main at 800 to 1000' feet. Gives more hang time to
get some positions to develop a trend line on the mapping solutions I use.
Am happy to report I've never lost an EggFinder/TRS rocket out of 8 flights so far with two totally sight unseen flights. Kurt
 
When you say patch antenna, is that for the TRS, or the LCD? If on the TRS, for the radio link to the LCD right? There is no way to add a external GPS antenna is there? I did mean to get a second SMA adapter for the TRS but guess I didn't make it super clear in my order e-mail. For now I will use the whip then change it out.
 
When you say patch antenna, is that for the TRS, or the LCD? If on the TRS, for the radio link to the LCD right? There is no way to add a external GPS antenna is there? I did mean to get a second SMA adapter for the TRS but guess I didn't make it super clear in my order e-mail. For now I will use the whip then change it out.

That's on the receive end you plug into the LCD. The picture below the "Patch" is the square antenna. I got it from a link that Cris had posted in the first user guide. Afraid it is not available anymore. Was $18.95 so that's why
I jumped at it. The fiberglass pole is an old 27Mhz fiberglass antenna I had lying around I use to get the antenna up in the air.

It does seem to improve the decoding of positions at altitude but it's not absolutely necessary for sport flying whatsoever. If one were trying to push the range of the system this would certainly help. Once the rocket is down, one can disconnect the patch antenna cable and connect something else. This assumes one uses some kind of SMA connector on their receiver. I had a bunch of plain SMA connectors lying around and not SMA-RP like can be had as an option.
I do have an adapter though if one wanted to "borrow" the patch with their SMA-RP receiver.

Again, if you're sport flying and just interested in getting your rocket back, this could be superfluous and is not absolutely necessary.

One thing that can help for ground recovery is a Yagi antenna of which one can find several on Ebay. It's easy to get one that's easy to carry in one hand. The technique is use your "duck" or vertical antenna to track the rocket in flight and when the rocket is down, you connect the Yagi. The Yagi has too narrow a beamwidth to properly aim at an out of sight rocket. That can lead to loss of position decoding and heaven forbid, a lost rocket with a completely
sight unseen profile. Use a patch, stock, or duck antenna to get some positions "in the can" so you know where to proceed to the last known position "after" the rocket is down.

I've proven to myself that the ground footprint is increased pretty significantly if there are no obstructions or the rocket doesn't land in a depression. If one is paranoid as I am, a Yagi will give peace o' mind once the beeping starts coming back on the LCD receiver. It will start beeping "sooner" rather than later. Absolutely necessary for a sport flier? Nah. But again, it's a little trick that can increase the range.

Ok, you say you see people pointing "Yagi" antennas skyward all the time. What's the deal? Am I full of animal excrement? (Full of garlic tinged excrement but definitely my own) Well, the beamwidth on the radio frequencies
that "those" fliers are using are workable for those bands. 2 meter, 1.25 meter and 70cm one can reasonably be able to point the Yagi in the proper direction and get a signal. You won't find anyone using the 33cm band (900Mhz)
"beeping" RDF tracking systems for in flight tracking for that reason. It works once the rocket is on the ground because the rocket isn't generally moving fast and you know the direction the rocket is at to point your Yagi.

Another modality is to use the Android app "GPS Rocket Locator" so you can get some positions plotted on a map to develop a drift trendline while rocket is coming in. If you get to the last known position and see no rocket
(or a fincan sticking up out of the ground, don't laugh that's how I found one rocket though the EF died an honorable death) you can proceed in the direction suggested until you hear the beeping. By this time, you might be antsy
and that Yagi can get you some peace o' mind here.

I'd say stock you're in pretty good shape for 2 to 3 miles. The key is getting the last position when the rocket is as low to the ground as possible. That will get you close enough if you don't see it, you get a new position.
You have to remember, I'm talking about a completely sight unseen flight. If one gets a visual on descent, that's icing on the cake if using any kind of radio tracking. The sight unseen one is where it really pays off.

Kurt

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Initial test was good to go. Now need to solder CPU and other remaining items. Excited!

Had a question though. The TRS assembly guide talks about suitable voltage input ranges, but the LCD does only mentions using either the 4 cell AA, or a 2S lipo. Can one also use a 3S lipo or is that too much for the power system to handle. I just happen to have a 3S that I can use for the moment.


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You could use a 3S LiPo, but the extra voltage just goes to heat. You're better off with a 2S. The 4xAA's last a long time... I think I've changed them once this year, and that includes being at LDRS for the whole week and a dozen flights.
 
I had a cheap radio shack switch:IMG_20171129_185644.jpg

That's the red button on the black cased LCD. I had a smaller button in there but I didn't like the way it felt on my finger since I was going to be using it more when flying a TRS. Tore the custom logo a bit putting the bigger button in.
The Black Aero case has a small button off to the right. It comes with the case.

Kurt
 
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