Eggfinder "waiting for fix" indications

[jrkennedy2]

I have a couple Eggfinders and one of them recently developed a problem getting a GPS fix. It synchs OK but then remains in Waiting for fix indefinitely (OK it was there for 90 minutes trying...). The 1S LED does flash at 1 second intervals after a few minutes. Where should I start looking to debug? It's sister synchs and gets fix in a couple minutes. It used to work fine so I reckon it got jarred on landing or some hanger-rash-like damage.

If there is a good prior post, I apologize for not finding it. The search didn't seem to turn up much.

 

[woferry]

You mentioned the 1S LED, what about the LEDs on the EF's Hope RF module? There's a red LED that should blink in rapid bursts once every second (not necessarily in time with the 1S LED) from the moment the board powers-up. Every 5th pulse is more like a double-pulse, it lasts longer than the 4 in-between. There's a green LED right next to the red LED that should not be lit.

On the receiver, it's green LED should match the red LED on the Eggfinder, at least assuming they're set to the same frequency/ID.

What generation EF TX do you have? Is it the newer one with the RUN/PGM jumpers? Or no jumpers at all?

Do you have one of the Prolific cables used to program the EF LCD? If so is it the 4-wire flavor or does it only have 3 leads on the non-USB end (and if there are only 3 what colors are they)?

These extra details may help determine what the next debug steps would be. You can also email [email protected], I've always gotten a quick and helpful response.

The fact that the 1S LED is blinking suggests that the GPS is working, so it seems to me like the GPS and Hope RF modules aren't "talking" to each other. If it's the newer board you may just not have the RUN jumper stuffed, otherwise something may be broken, but if you have the (proper) Prolific cable it might help confirm the state of the GPS module.

 

[cerving]

Did you ever get a fix with it? Usually if you get the 1S light that means that the GPS radio is OK, so it's the interface to the RF module that's the problem. That usually means one or more of the solder joints on the GPS module around those two 2.2K resistors and the 10K resistor, they control the data format going to the RF module. Check everything with a 10x jeweler's loupe, be especially careful to check that solder actually wicked up to the pads to the "half moon" cutouts on the GPS module... it's easy to cover the pad but actually miss the GPS module.

If that looks OK and the red LED on the RF module is blinking with the 1S light, try re-programming the RF module with the pairing cable and the LCD receiver (if it's a B6 board).

 

[jrkennedy2]

I'll get this info to ya'll this evening. Much thank for you guidance!

 

[jrkennedy2]

https://www.dropbox.com/sh/mlg1aqiubolqwft/AAAcuytKtpkdhnkV_abOCVZ9a?dl=0

Above is the link to a couple pictures and a video. I'll go hunt-up my cable to try and reprogram the unit since it was running last launch and so I "think" the solder connections were ok.

In the vid you can see S1 and the red transmit led also blinking.

 

[jrkennedy2]

Hummm. Does the B6 TX use the USB cable to the PC? If so, what is the pin-out, green, white, black? The instructions indicate you plug it into the RX? My RX is the TRS design and does not have a USB that I have noticed. So I don't waste your time, is the a link to documents that discuss B6 TX to PC via USB cable?

 

[ksaves2]

Hummm. Does the B6 TX use the USB cable to the PC? If so, what is the pin-out, green, white, black? The instructions indicate you plug it into the RX? My RX is the TRS design and does not have a USB that I have noticed. So I don't waste your time, is the a link to documents that discuss B6 TX to PC via USB cable?

I don't think there is a programmer for the computer/laptop. Read page 24 in the user quide: https://www.eggtimerrocketry.com/attachments/File/Eggfinder_Users_Guide_RevB6.pdf
Kurt

 

[cerving]

You don't use the USB-Serial cable to program the TX, you use the 3-pin jumper cable that comes in the package. It connects to the 4-pin connector on the Eggfinder LCD receiver's board (yes, you have to open up the case), and when you program the LCD receiver it also programs the TX to the same frequency/ID. See Page 24 of the Eggfinder User's Guide, https://www.eggtimerrocketry.com/attachments/File/Eggfinder_Users_Guide_RevB6.pdf

 

[jrkennedy2]

Yeah, I took it out of the case. :wink: I'll have to verify my LCD pin-out vs the B6 pin-out. I sorta think my LCD and B6 won't pin-out right even rotating one end 180 degrees. My LCD (for that matter my TRS) were very early generation units. And yes they have worked VERY well up 'till this minor glitch! I'm very happy with them.

 

[jrkennedy2]

In the url above I added pictures of the pin-outs. With the TX being on the outside one one and in the middle on the other, they appear incompatible. I need the pin-out map pings before I start cutting cables. What is BV3? I understand GND and TXD but that other escapes me. The labels on the LCD are straightforward. Could it be 3V3 to match 3.3V on the LCD?

 

[jrkennedy2]

Aw geezze that was bad. It's not a 180 degree rotation. It's an arithmetic shift left! Duhhhhh!

After re-syncing it, now it works fine. Just for my understanding, what would make it lose its programming? Static?

 

[ksaves2]

JR, Feels good to get it fixed, don't it? I don't know what would get it to lose it's settings. I have just one of the v2 (B6's) and the are rest B5's. Haven't noticed a problem yet with it. I constructed one of the first TRS controllers out there and discovered
two of the pin positions were switched as opposed to the EggTimer deployment computer. I emailed Cris and by golly he didn't realized they were different on the TRS and then changed the TRS manual to reflect the fact. Kurt

 

[jrkennedy2]

I think I'm going to get another LCD unit and run it at a different freq. That way I can track the booster stage of a couple HP 2-stagers I have. I'm getting almost too reliant in these Eggfinders.

Thanks to all for the guidance!

 

[atypicalguy]

Ok C means course. The arrow shows which way to turn to achieve the course.

D must be distance.

T and R I have no idea. I should think course and distance would be sufficient?

 

[sl98]

Ok C means course. The arrow shows which way to turn to achieve the course.

D must be distance.

T and R I have no idea. I should think course and distance would be sufficient?

Pg 30-31 explains T, R, C, etc.
https://eggtimerrocketry.com/wp-con...finder_LCD-GPS_Assembly_Users_Guide_w_Pix.pdf

 

[cerving]

C: Compass direction from you, North-Up
D: Distance from you in whatever units you have programmed (ft or meters)
T: Your track (the compass direction that you are moving... you have to be moving for this to update, every 10 seconds)
Arrow/Bearing: The direction and bearing to your rocket IN RELATION TO THE DIRECTION THAT YOU ARE MOVING.

So, if you follow the arrow, no matter which way you are moving, you basically will get dropped right on top of your rocket.

 

[atypicalguy]

Well this worked very well for the L1 cert flight on Saturday. We pretty much walked right up to the rocket, after losing complete sight of it on an H115 (Simmed to 4600 ft but I didn't run an altimeter). I knew roughly what direction it went but it landed 1380 feet off the end of the flight line.

Does the LCD store the GPS data anywhere that it would be downloadable? Would be cool to graph the flight and show it to my 8yo, who came out with me to find the rocket and was pretty excited that we succeeded in the L1 attempt

 

[cerving]

The GPS data is not stored, only the last fix location (that's in case you lose power, you can retrieve it by hitting the button at "Waiting for Fix"). If you want to record the data, you can connect an OpenLog datalogger to the 4-pin Bluetooth header.

 

[atypicalguy]

Ok so just mount the logger in the LCD case and hook up to the bluetooth header? I will look into it. Thanks, Karl

 

[Bill Hanson]

Ok C means course. The arrow shows which way to turn to achieve the course.

D must be distance.

T and R I have no idea. I should think course and distance would be sufficient?

Getting ready to start building mine.

Did you 3D print your case? If so, can you share a link to the design?

Thanks in advance!
Bill

 

[WoShuGui]

The GPS data is not stored, only the last fix location (that's in case you lose power, you can retrieve it by hitting the button at "Waiting for Fix"). If you want to record the data, you can connect an OpenLog datalogger to the 4-pin Bluetooth header.

Will connecting a logger or Bluetooth to the header not disable the button? Or is this no longer the case with the more recent LCD receiver software?

 

[Eric]

That printed RX case is from BlackAero. They are very nice.

I thought the data logger was mounted to the TX side of the original EF. Never seen one on a mini.

 

[Voyager1]

Getting ready to start building mine.

Did you 3D print your case? If so, can you share a link to the design?

Thanks in advance!
Bill

I think it might be this one.
https://www.blackaero.com/shop-2/eggfinder-lcd-case

 

[cerving]

Will connecting a logger or Bluetooth to the header not disable the button? Or is this no longer the case with the more recent LCD receiver software?

The button and the headers are two separate things, there has never been an issue with the button and connecting things to the headers.

 

[Bill Hanson]

That printed RX case is from BlackAero. They are very nice.

I think it might be this one.
https://www.blackaero.com/shop-2/eggfinder-lcd-case

That's it! Thanks very much.
- Bill

 

[ksaves2]

It is possible to pipe the incoming stream to an APRS tracking program but it's an involved ordeal. Once setup though one can do a screenshot and have a record of the flight. With a program called Xastir one can save the positions and repaint them on the map. Major problem is program setup learning curve is extremely formidable involving extensive setups and software hacks.