# Problem programming the frequency on Eggfinder Mini

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#### SoCalChris

##### Well-Known Member
I recently finished an Eggfinder Mini, and went to program it.

I followed the instruction to remove the solder bridge on RUN, and create a bridge on PGM. I hook up the programming cable from the LCD receiver to the Eggfinder Mini. I go into programming mode, and can successfully set the frequency. However, after the following step when setting the ID, the LCD freezes, and both the red and yellow LEDs on the receiver board illuminate solid until I turn it off. Additionally, the screen freezes. If I try this with my regular Egggfinder, it has no problem and tells me to reset the receiver for changes to take effect.

On the EggFinder Mini:
• When I initially turn it on, the two LEDs on the radio board illuminate briefly
• The large amber LED is dark for a few minutes. After a few minutes, it begins flashing amber.
• The receiver never connects with the transmitter, it just stays stuck at "Waiting for fix"

Any suggestions what I might have done wrong, or where to start looking would be greatly appreciated.

Thanks

#### Voyager1

##### Well-Known Member
TRF Supporter
After you power up the Eggfinder Mini (without it connected by the programming cable to the LCD receiver), does the red LED on the RF module continue flashing about once per second? If this is not happening, then I would possibly suspect a soldering problem with the RF module. The amber LED will begin flashing after the GPS module has sufficient satellite signals to have a fix, but if the red LED on the RF module is not flashing too, then your GPS data is not being transferred to the Mini's RF module. The fact that the 2 LEDs on the Mini RF module flash briefly when you power up the Mini is just indicating that the RF module is being powered up, it does not necessarily mean that the GPS data is getting to it. Check your soldering around the RF module carefully. Check for solder bridges between RF module pads, and while you're at it, check around the GPS module too.

If you're having difficulty programming the Mini from the LCD receiver while connected with the cable, a program hangup could suggest that the data line to/from the RF module is behaving intermittently and should be checked.

Talk to Cris.

All the best.

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
Voyager1 pretty much said what I would have said. It's most likely a solder joint somewhere, probably on the RF module. The lines that are used to program it aren't used during normal operation, so you'd notice that there was an issue when you went to program it.

#### SoCalChris

##### Well-Known Member
Thank you guys for the suggestion, I will take a look at that today and see if that takes care of it.

#### SoCalChris

##### Well-Known Member
So I finally had a chance to look over the solder joints, and didn't see any broken connections or bridges. I reflowed all of the joints between the GPS and board, and the board and RF module and am having the same issue. I've attached pictures, and a video of what it's doing when I try to program it. You can also see the solder joints a little better in the video than the pictures.

Does anyone have any other suggestions? Does Egg Timer have an "I screwed this one up, I need to buy another" discount?

Thanks again!

#### Voyager1

##### Well-Known Member
TRF Supporter
Just a couple of things. I assume that you insulated the underside of the RF module PCB with masking tape before soldering it into place. Also, with the link in the RUN position, you didn't confirm whether the red LED on the RF module flashes when the amber GPS LED flashes once acquisition is achieved. Both LEDs should be flashing. If this is not happening then you probably have a break in the connection between the GPS module and the RF module, or the RF module is faulty.

#### SoCalChris

##### Well-Known Member
Yes, there is tape between the modules as per the instructions. No, the red led does not flash.

Thanks

Sent from my Pixel XL using Tapatalk

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
Any issues with solder joints would be on the RF module side, not the GPS. Specifically, it would be the last three pins on the right side of the module. When you pair the LCD receiver with the Mini, do the red and green LED's on the Mini come on at the same time that they do on the LCD's RF module? If not, then you're either not getting a good connection between the LCD and the Mini, or there's a bad solder joint on those RF module pads.

#### Voyager1

##### Well-Known Member
TRF Supporter
From the video you don't appear to have either of the green and red LEDs on the RF module ON while connected to the LCD unit while in program mode. As Cris said, you need to see both of these ON when in program mode and paired with LCD unit.

Also, if you are not seeing the red LED flashing when in RUN mode, then you do seem to have a problem with the connections to the RF module.

Both these symptoms appear to point to the solder connections to the RF module. You may have track separation or open circuit, short circuit (solder bridge) or damage to the RF module IC. I suggest you get a copy of the HopeRF module data sheet and investigate the voltages/signals on the relevant pins on the right hand side of the RF module in your 3rd image.

#### ksaves2

Don't feel bad. I whacked a Quantum with solder under the wifi chip (likely), dropped a perfectly good EggFinder on the floor 30 minutes after completing and test proven to work breaking the GPS antenna off the base and toasting a wireless Rf switch on an ematch test. I don't know what went wrong there but the kit was so cheap I wrote it off. Yeah, hard to swallow dorking a Mini but look at it this way, it's not a  Beeline GPS!! I ballistically tested an EggFinder and sorry to say it failed the test!:shock::eyeroll::wink:.

But I "DID" find the rocket to dig out, replace the nosecone, Eggfinder and it still flies. Would have been turned over into the ground by a plow this year if I didn't have the EF onboard.

If it's the GPS, the base can be a bear to get off without the proper equipment as is the Hope module. The GPS base if you look close has a slot that I think I discovered if one sloshes solder in there can dork the GPS.

#### SoCalChris

##### Well-Known Member
Any issues with solder joints would be on the RF module side, not the GPS. Specifically, it would be the last three pins on the right side of the module. When you pair the LCD receiver with the Mini, do the red and green LED's on the Mini come on at the same time that they do on the LCD's RF module? If not, then you're either not getting a good connection between the LCD and the Mini, or there's a bad solder joint on those RF module pads.
Just to verify, these are the pins you're referencing?

From the video you don't appear to have either of the green and red LEDs on the RF module ON while connected to the LCD unit while in program mode. As Cris said, you need to see both of these ON when in program mode and paired with LCD unit.

Also, if you are not seeing the red LED flashing when in RUN mode, then you do seem to have a problem with the connections to the RF module.

Both these symptoms appear to point to the solder connections to the RF module. You may have track separation or open circuit, short circuit (solder bridge) or damage to the RF module IC. I suggest you get a copy of the HopeRF module data sheet and investigate the voltages/signals on the relevant pins on the right hand side of the RF module in your 3rd image.
That's correct with the lights, you've described the behavior that I'm seeing. Do you have any suggestions on where I should be checking for issues with the soldering? Or mainly focus on the three pins going to the RF module that Cris mentioned?

Don't feel bad. I whacked a Quantum with solder under the wifi chip (likely), dropped a perfectly good EggFinder on the floor 30 minutes after completing and test proven to work breaking the GPS antenna off the base and toasting a wireless Rf switch on an ematch test. I don't know what went wrong there but the kit was so cheap I wrote it off. Yeah, hard to swallow dorking a Mini but look at it this way, it's not a  Beeline GPS!! I ballistically tested an EggFinder and sorry to say it failed the test!:shock::eyeroll::wink:.

But I "DID" find the rocket to dig out, replace the nosecone, Eggfinder and it still flies. Would have been turned over into the ground by a plow this year if I didn't have the EF onboard.

If it's the GPS, the base can be a bear to get off without the proper equipment as is the Hope module. The GPS base if you look close has a slot that I think I discovered if one sloshes solder in there can dork the GPS.

This is actually my fifth Eggtimer product that I've attempted. The first was a Quark, it was going along fine until I accidentally dumped the parts on the floor, most of which were never seen again. I successfully built another Quark after that mishap, then a successful EggFinder and EggFinder Receiver. Now I'm trying to get this Mini working.....

Thanks for the help everyone.

#### RocketDestroyer

##### Well-Known Member
What are you using for a soldering iron?

Terry

#### cerving

##### Owner, Eggtimer Rocketry
TRF Supporter
Looking at the pictures, I see some issues with the solder joints. It looks like they're overheated, and there's too much solder too. You got solder splatter all over the board. I recommend that you get a smaller tip and/or turn down the heat, cover the RF module with some masking tape, then get out some desoldering wick and remove the excess solder on the RF module pads. Get an old toothbrush and brush the splatter away from the board (one direction only, towards the outside, and don't spray any "component cleaner" on them!) Then, resolder them. Take a look at the pictures on the Eggtimer Rocketry web site, if your solder joints don't look like that then they're not right.

#### SoCalChris

##### Well-Known Member
Thanks for the suggestions. I had picked up a much smaller iron tip yesterday, so I will wick the excess solder off, clean it as you suggested, and try again.

Thanks again for the help.

#### Voyager1

##### Well-Known Member
TRF Supporter
Personally, I use a range of tips for my soldering from 0.3 mm to 2-3 mm (various profiles: conic, bevel, chisel, etc), depending on the thermal load at the particular joint. For all the Eggtimer boards I have made, I generally used 0.3 - 0.5 mm conic tip, particularly for the SMT components, sometimes a 1 mm tip.

Preferably use an iron that's not too bulky, and use a good magnifying system with good lighting. I use a stereo microscope with an integrated lamp for all SMT soldering because my eyes are no good for unaided close work these days. Get yourself a range of solder wick sizes too. A flux pen is useful to aid de-soldering by applying a little to the wick before applying heat - but not too much.

Always keep the tip clean after every joint to remove the fried flux and excess solder. It may help to pre-tin the tip with a small coating of fresh solder, but be careful not to have a blob of it hanging there. Also, I find that briefly pre-heating the joint area before applying the solder to it helps the solder to flow more evenly. The operation should only last a couple of seconds to minimise the risk of overheating, and leave it for up to 30 seconds to cool. The joint should look shiny, not dull or crystalline.

I totally agree with the advice Cris has given you, particularly about the amount of solder you use on a joint. If you use too much, there is more chance of bridges and heat damage to tracks and adjacent components.

#### Voyager1

##### Well-Known Member
TRF Supporter
If you wish to attempt some fault-finding then download a copy of the HopeRF HM-TRP series data sheet from

https://www.hoperf.de/rf/fsk/HM-TRP.htm

I think that this is the correct one. Cris may need to confirm this.

However, if you're not confident with a data sheet, multimeter and/or oscilloscope, or don't have a reasonable grounding in electronics, and a reasonable understanding of how the Mini circuit works, then don't attempt it. The damage is probably done and you are better off buying a new kit and putting it down to experience.

All the best

#### RocketDestroyer

##### Well-Known Member
I highly recommend buying and using a good, temperature controlled, and grounded iron. Yes they cost more but it is worth it to have a quality finished product.

Terry

#### SoCalChris

##### Well-Known Member
Personally, I use a range of tips for my soldering from 0.3 mm to 2-3 mm (various profiles: conic, bevel, chisel, etc), depending on the thermal load at the particular joint. For all the Eggtimer boards I have made, I generally used 0.3 - 0.5 mm conic tip, particularly for the SMT components, sometimes a 1 mm tip.

Preferably use an iron that's not too bulky, and use a good magnifying system with good lighting. I use a stereo microscope with an integrated lamp for all SMT soldering because my eyes are no good for unaided close work these days. Get yourself a range of solder wick sizes too. A flux pen is useful to aid de-soldering by applying a little to the wick before applying heat - but not too much.

Always keep the tip clean after every joint to remove the fried flux and excess solder. It may help to pre-tin the tip with a small coating of fresh solder, but be careful not to have a blob of it hanging there. Also, I find that briefly pre-heating the joint area before applying the solder to it helps the solder to flow more evenly. The operation should only last a couple of seconds to minimise the risk of overheating, and leave it for up to 30 seconds to cool. The joint should look shiny, not dull or crystalline.

I totally agree with the advice Cris has given you, particularly about the amount of solder you use on a joint. If you use too much, there is more chance of bridges and heat damage to tracks and adjacent components.
I have a reasonable soldering iron, it's an entry level adjustable Weller station. I have a feeling a lot of my problem is that I used the tip that it came with, which is probably way too big for this project. I think that between that and possibly having it set too high was my main issue.

If you wish to attempt some fault-finding then download a copy of the HopeRF HM-TRP series data sheet from

https://www.hoperf.de/rf/fsk/HM-TRP.htm

I think that this is the correct one. Cris may need to confirm this.

However, if you're not confident with a data sheet, multimeter and/or oscilloscope, or don't have a reasonable grounding in electronics, and a reasonable understanding of how the Mini circuit works, then don't attempt it. The damage is probably done and you are better off buying a new kit and putting it down to experience.

All the best
Thanks for the link, I will check that out. I will try cleaning this up the way you guys have mentioned, if I can't get it straightened out I'll probably try another with the conical tip.

Thanks again everyone for the help.

#### ksaves2

The smaller the better. The nice soldering stations are great but I've got all my stuff together with an el cheapo 15 watt pen with very fine tips. I have to replace the tips as they eventually fall apart but that's it. If they develop a concavity at the tip that's
a plus as I can exploit that to carry a bit of solder to tack a part down. Once "tacked" I can use two hands, one for the pen and one for the solder to complete the process and have good two-handed control. Kurt

#### SoCalChris

##### Well-Known Member
Ok, follow up question for Cris or anyone else who may know. I purchased a replacement Eggfinder Mini kit. In the parts, I don't have any resistors marked 331 as noted in the instructions, but have two marked 3300 which I can't find referenced anywhere. Are these equivalent?

Thanks!

#### OverTheTop

##### Well-Known Member
TRF Supporter
331 is a code showing 3 + 3 + one extra zero. It is effectively the same as the old 3-band resistors, without the color stripes. 330 ohm.

3300 is 3 + 3 + 0 + zero extra zeros. 330 ohm. Same same.

The origin of this is the higher tolerance resistors that need more resistors in each decade of resistance to get the required spacing between adjacent values. The third digit is needed for the resistance value:
https://www.logwell.com/tech/components/resistor_values.html

#### SoCalChris

##### Well-Known Member
Thanks, I spoke to Cris and he confirmed that as well.

#### ksaves2

Go get them! Call Kurt

#### Jamieson

##### Member
I had a very similar programming my eggfinder Mini RX I fought it a long time. Turns out there was a break in the middle wire of my 3 wire cable. Replaced it and all is well.

#### conman13

##### Well-Known Member
If you weren’t able to get the old mini working I’d be willing to take a look at it for you if you’d like. I’ve been assembling Cris’s kits for people for a couple years now so I’ve assembled quite a few of the minis. Shoot me a message.

Edit: whoops didn’t even look at the date of thread as the thread popped up in the new posts! Offer still stands but disregard otherwise