Eggfinder B6 version

I just finished building the new version B6 Eggfinder TX GPS Transmitter. This was the easiest of all of Cris's kits. Cris removed a few components and added some cool features. All of the passive components like resistors and capacitors are surface mount. Although they are small they are easy to solder after a little practice. The unit self starts on power up and is polarity protected. You can hook up your battery either way and it does not matter. Biggest feature, up to 72 channels can be programmed. All you have to do is use a patch cord to the LCD receiver and change the frequency. The TX is automatically changed. The pads on the GPS are enlarged so it is easier to solder.
Thanks Cris

Are there fewer LEDs? I only see 1!

I agree. I just built mine yesterday, and, found it much easier than a Quark altimeter that I built a few days ago. In building the two kits, I've also found the surface mount parts easier to install than the through hole parts. The instructions were very precise, and easy to follow.

timbucktoo said:

Are there fewer LEDs? I only see 1!

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There is only one LED to install, the amber GPS lock indicator. The others are included on the RF board.

That's right, only one LED. The switch, 2 LEDs, Small processor, one resistor and capacitor are all not needed. This is a very clean board with minimal components. More capability with fewer components. A real Home Run for Cris. Only downside is that it does not run on a 1s 3.7 v Lipo. I can live with that.

The older version technically wouldn't run on a 1S LiPo either, but it DOES work. So would this one, but you'd have to bypass the bridge and voltage regulator, and if you hook it up backwards, poof! I put the bridge in because I heard way too many stories of people frying their transmitters with reversed LiPo's (you CAN hook up those cheap Chinese-clone JST connectors backwards...), and since the regulator's Vout+Vdo voltage was technically just outside a 1S LiPo the extra 1V dual-diode drop wasn't a factor.

What's the "RUN" jumper, on/off?

Chris you are right about the voltage drop. On one of my older GPS units I added a diode and that's exactly what it did. I really like the safety factor of the diode or the rectifier but on some of my tiny Rockets I need the ability to use a single cell lipo. Nice to know that I can make the modifications to the B6 if I have to use it for a small rocket. F

timbucktoo said:

What's the "RUN" jumper, on/off?

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That's for programming the frequency with the EF LCD receiver. This transmitter is frequency agile and needs to be able to plug-in to the programming header on the
back of the EF LCD board. You put the EF LCD in programming mode, go to frequency and the frequency you set for the EF LCD is the frequency you get on the EF GPS. I believe the 0-7 sub channel can be programmed also. The jumper on the EF GPS is set to allow programming.

The original EF GPS was fixed frequency and no sub channels. This will allow for a lot of folks to fly and track at the same time. Only issue is one might want to try to make that header "field" accessible or buy a second EF receiver that is "packaged" to allow for easy re-programming of the EF GPS. The header is what one also plugs the B/T module into so you have to disconnect it to be able to program an EF GPS.


Kurt Savegnago

Assuming that one does NOT have the LCD receiver, can this new TX still be programed?

Banzai88 said:

Assuming that one does NOT have the LCD receiver, can this new TX still be programed?

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Cris? Me suspects not easily. But why would it be necessary to program a newer EF GPS if you have an older style receiver? That unit would be fixed frequency at ID 0 anyways and the older style EF GPS transmitter was fixed frequency anyways.

If you were ordering a new EF GPS, you would just have to tell Cris what frequency you wanted it on so he could program it for your older receiver. I'd get an EF LCD if I were you so there would be the programming ability for any newer EF GPS transmitter. Kurt Savegnago

Banzai88 said:

Assuming that one does NOT have the LCD receiver, can this new TX still be programed?

Click to expand...

It would be harder to do, but it should be possible with something like the Prolific serial adapter Cris provides or an FTDI adapter you can buy from elsewhere. You'd have to know the exact commands to send via a PC/Mac, it's definitely harder and riskier (if you send the wrong command to the RF module I believe you can brick it, or at least make it much harder to get working again).

Note that the power received on the B6 board's 3-pin header goes directly to the Hope module (the GPS also I think), so it needs to be 3.3V. The Prolific adapter (I believe) and some FTDIs provide 5V, so it would very likely destroy things to make that connection instead of the expected 3.3V. But if you fed the 5V in where the battery goes instead I believe it would work (no guarantees however, the GPS might draw more power than the USB-to-serial things are designed to provide), or if you used a USB-to-serial adapter that provided 3.3V instead of 5V it should definitely work, you should also be able to connect the normal TX battery and only make the GND and TX connections to the B6 board.

I actually built an RX to do basically this, I made a few hacks during soldering and added a 2-position switch so that my RX can either be in "run" mode or "program" mode, and I could just send the right serial stream from a script to change the RX's frequency in program mode. I did this since I like to have an LCD in my hand for walking to the rocket, and an RX connected to my laptop back at camp to record the full path of the rocket. The RX is built and works as expected, I still need to clean up my script so that I can feel more safe using it, at my last launch I just bounced between this one and my original non-hacked RX when I wanted to change frequencies to avoid having to reprogram the RX at the launch.

I should note that if you run Windows (so I'd stop reading right here ) I'm pretty sure there is software that can reprogram the Hope module, so that part would be a bit easier, just connect the cable with the proper power and use the program to change the settings. The only setting to change in this case is the RF frequency, and each ID step is another 250kHz (so "909 ID 5" is actually 910.250MHz).

This is what my external programming pigtail looks like.

Nice unit Steve. Is that a digital voltmeter in the upper right? Do you have a B/T board installed and how do you share the header if you do?

Kurt Savegnago

ksaves2 said:

Nice unit Steve. Is that a digital voltmeter in the upper right? Do you have a B/T board installed and how do you share the header if you do?

Kurt Savegnago

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Yes Kurt it's a volt meter(hate making square holes). No Bluetooth so I just cut the cable in half and soldered it to a surplus jack.

Very nice job Steve!!!

I'm interested in the the din/mic/multi-pin connector you used. Part numbers?

n27sb said:

This is what my external programming pigtail looks like.
View attachment 273501View attachment 273502

Click to expand...

scsager said:

Very nice job Steve!!!

I'm interested in the the din/mic/multi-pin connector you used. Part numbers?

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I got it from the local surplus store here in Orlando. They have thousands of the panel mount side but just a handful of the cord end. Every now and then you get lucky and find one that matches. This one was a dollar 50. It has five pins. Just about anything with three pins would work but they tend to be expensive. Sorry I can't be any more help.

Radio Shack carries 5-pin DIN plugs and sockets, if you can still find one...

scsager said:

Very nice job Steve!!!

I'm interested in the the din/mic/multi-pin connector you used. Part numbers?

Click to expand...

You can get those both sides panel mount and cord connector
at either Digi Key or Mouser.....

Teddy

I wonder if there is a Quad pole double pole switch one could install so they could switch from a bluetooth module to a programming socket/outlet? Any ideas? Would be amenable for reprogramming on the field as opposed to opening up the
LCD unit, disconnecting the B/T module cable and manually attaching the B6. Kurt Savegnago

Actually, you only need to disconnect the TX & RX lines... you could leave the power on if you want. That makes it a DPDT switch, easy to find. Even easier would be if you got a DPST switch and just disconnect the Bluetooth TX/RX lines when you flash the receiver.

n27sb said:

I just finished building the new version B6 Eggfinder TX GPS Transmitter. This was the easiest of all of Cris's kits. Cris removed a few components and added some cool features. All of the passive components like resistors and capacitors are surface mount. Although they are small they are easy to solder after a little practice. The unit self starts on power up and is polarity protected. You can hook up your battery either way and it does not matter. Biggest feature, up to 72 channels can be programmed. All you have to do is use a patch cord to the LCD receiver and change the frequency. The TX is automatically changed. The pads on the GPS are enlarged so it is easier to solder.
Thanks Cris

View attachment 273458

Click to expand...

"The TX is automatically changed" Really??? I hooked up the 3 wire jumper and my LCD Rx wont go any further than "Waiting for fix" Is it not syncing with the new TX or what? When turned on, It says the freq is 909 0 which is the freq of my RX but it never gets a fix. And when I hear someone talk about their Rx making a beeping noise Im really confused cause mine NEVER has beeped. Im no electronics OR computer wiz like most of you guys so please explain in simple terms. And if I cant get this freq set can I send it to one of you Wiz kids to set for me?

The TX is automatically changed to the same frequency as the LCD receiver when you connect the two of them and go into the programming mode on the LCD receiver. There's a page on it in the TX B6 manual.

You have to have a fix to get a beep, you don't have a fix so no beep. You'll know when you do, believe me.

Check the red LED on the TX's RF module and the green LED on the LCD's RF module, they should be blinking in-sync about once per second. If they are not, then you don't have communication between them... either they're not on the same frequency/ID, or you're not putting out good data on the TX. Also, you should test outdoors... GPS is very sketchy indoors.

cerving said:

The TX is automatically changed to the same frequency as the LCD receiver when you connect the two of them and go into the programming mode on the LCD receiver. There's a page on it in the TX B6 manual.

You have to have a fix to get a beep, you don't have a fix so no beep. You'll know when you do, believe me.

Check the red LED on the TX's RF module and the green LED on the LCD's RF module, they should be blinking in-sync about once per second. If they are not, then you don't have communication between them... either they're not on the same frequency/ID, or you're not putting out good data on the TX. Also, you should test outdoors... GPS is very sketchy indoors.

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I AM outdoors. I told you when I purchased it what freq I wanted but you said that I could do it. Ive been trying for a week and Im about at my wits end trying to figure it out.

bill2654 said:

I AM outdoors. I told you when I purchased it what freq I wanted but you said that I could do it. Ive been trying for a week and Im about at my wits end trying to figure it out.

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Bill,

Read the manual and make sure you have the connections correct on the EggFinder LCD to the B6. Make sure the jumper setting is correct on the B6. If I recall correctly, the B6 will get its power from the EF LCD.
You need to get the EF LCD in programming mode. Get the the frequency and set it. Get to the mode and set it (0-7). Both units should be ready to go then. You do have an EggFinder LCD receiver right?
If not, you'll have to get access to someone who does have one.

Also, if you don't know the frequency your B6 is on. Reprogram your EF LCD for each frequency until the receiver "hears" the frequency your transmitter module is on. Once that's done. You can reprogram the units to the frequency you want.
I would suspect that Cris would ship the Hope module on some frequency and mode 0.

As an aside, some of these cheap DTV dongles can be turned into a basic spectrum monitor: https://www.gearbest.com/tv-box-mini-pc/pp_188367.html?currency=USD&gclid=CMyl7bCIscgCFUc7gQode9IFiw

Using software like this: https://www.rtl-sdr.com/big-list-rtl-sdr-supported-software/

If it was me and I didn't know what the module was on and was lazy, I'd fire up Gqrx on my linux laptop: https://gqrx.dk/ and look for the peak on the spectrum to get the frequency. But......... It's probably easier for you to set a frequency on your EF LCD and see if the led flashes on the Hope module that indicates a lock. Kurt

Now I know why I was having all my troubles. I didn't see the step that says "move the jumper from Run to PGM. It makes all the difference. Got a fix now!

bill2654 said:

Now I know why I was having all my troubles. I didn't see the step that says "move the jumper from Run to PGM. It makes all the difference. Got a fix now!

Click to expand...

:bangpan:

Kurt, the "mode" thing is something Im still confused on. I have 2 systems. I have a complete TRF system and I also have the new B6 Tx. Both are on Freq 909 0. Is this right or should my extra Tx be set on 909 1?

bill2654 said:

Kurt, the "mode" thing is something Im still confused on. I have 2 systems. I have a complete TRF system and I also have the new B6 Tx. Both are on Freq 909 0. Is this right or should my extra Tx be set on 909 1?

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That mode tag is so with the available frequencies and modes, 72 units can be in use at the same time. You can be on 909 mode 0 and someone else can be on 909 mode 1-7 and the frequency can be shared if I understand Cris correctly.
The bottom line is the transmitter and receiver have to be on the same frequency and mode number for the transmitter to be heard at the receiver. The mode option was available for the EggTimer TRS so many units could fly without
interference. Cris changed the B6 EggFinder GPS to this for greater utility

The 1st generation EF GPS was on a fixed frequency and mode 0. If you use one with the EF LCD you have to set the frequency that the EF GPS is transmitting in the EF LCD and leave the mode to 0 on the EF LCD. Kurt Savegnago
(If I'm incorrect perhaps Cris will chime in. I'm only a user of the product and live 1/2 a continent away from him)

Thanks for the reply Kurt, you explained a lot. First I used to have one of the first generation Tx's and I used both it AND my TRS on the same frequency 909 0 without changing the mode number. I finally figured out (after messing with it for 4 hrs) that the new generation Tx has to have a different mode number or the LCD receiver wont fix on it. I read the instructions and I'll be damned if I could find that info anywhere. Correct me if I over looked it.