GPS PLUG CONNECTION FIX
- Thread starter flyNfrank
- Start date
vk3bq said:
I've been playing with a Raspberry Pi and recently obtained a GPS module. All that's needed is Tx/Rx data and power. I suspect the Phantom GPS module works similarly.
flyNfrank said:
I am replying to this to say that, as an eductated engineer, this paragraph is full of incorrect information and nonsense. I don't want to make this personal, I simply want to give guidance to anyone who is reading this thread that may not have a technical background and may not know who is right and what to believe here. What vk3bq is saying makes sense 100%. What Frank is saying does not. I don't care how long anyone has been a forum member, etc. I'm just trying to prevent the spread of misinformation.
From the links provided, the cable appears to carry a digital signal with data integrity checks (checksum). This essentially means it's going to be an all or none signal. Either all the (correct) information from the GPS module is transferred, or none of it (either because a complete loss of connection or because it will be rejected if too "garbeled"). I believe the only way that improving this conne would result in more GPS satellites being seen is if there is EMI coming FROM the connector/wires that interferes with the upstream GPS antenna. This is NOT what Frank is saying.
Many people have found that even though the connector wiggles, the connection remains intact. Yes, it appears a better quality connector could have been used. Whether the connector has led to cases of actual loss of GPS in flight, perhaps. Will the quad "drop" if this happens or have an "active" flyaway (other than entering ATTI and drifting)... I highly doubt it and will continue to highly doubt it until someone can provide evidence of this happening, or at least an explanation that makes SENSE.
max said:
You do realize 85% of your post are criticizing some thing or someone. There is no real benefit in judging others as you do either. If you didn't use my name to share your opinion on the matter this may have been one of the few time you finally contributed something of substance. But instead it just looks like the usual lashing out you are known for. How long would anyone hangout in this forum if everyone spoke of one another in the manner that you do most of the time? I lashed out a few post back which was just the 2nd time since becoming a member over a year ago. The other time was just a day or two earlier. Goes to show you I'm getting sick of single digit weather and have cabin fever. When you post and discuss the subjects that I get involved in, you eventually say something that others will not agree with. Rather then using 2nd accounts and jumping in someones thread and telling them they're all wrong, ect. Respect the fact that they are at least trying to contribute something and let it move forward. Otherwise it will just become all negativity like we have here now.
I have a feeling max you have a lot of good to contribute.
2nd accounts? Frank I'm new to this place. I asked some questions. I tried to expand some ideas. And contribute some, as any scientist does. Question. Challenge. Discuss. And ultimately improve understand. . For that I'm a trouble maker. Who is WRONG because it's my 1st post. Who is hijacking your thread. Really. Land of the free "unless I don't agree with you" Andrew. Vk3bq. From Melbourne Australia. :$ I'll go back to my Vegemite.
Frank, let the people with knowledge, expertise and no-how work... AND they will contribute to the betterment for us all....
do you have a problem with that?
do you have a problem with that?
I personally don't see anything wrong with an educated engineer (or anyone else having related expertise) correcting someone's post if it contains information that is incorrect or based on a well-meaning but scientifically incorrect assumption -- and I welcome and appreciate the information.
I think someone might need a Snickers bar.
I think someone might need a Snickers bar.
Ok, here is what I sourced and a brief explanation for what I found either good or bad about a given item. Also two variation for those that want to perform the DIY fix to their GPS connector.
Let’s talk connectors first, the little copper crimp pins inside the plastic plugs. DJI’s offering had very low tension. Either vibration or several removals from the plug allows the contact fingers to lose tension. Basically deforming to allow a poor contact to the male pin on the main board. Further DJI’s appear to be of copper only, no plating on the contact fingers. Bare copper will corrode.
Further, plain copper does not have a great ability to have strength from bending. Bend it enough and it will break or deform out of the way. I bought an RC dealers variation for the items below and had the female pins lose tension after a couple installations, much like the DJI. Those will end up as practice connectors and are shown below as a further example.
I choose a Phosphorus Bronze connector that was gold plated. Phos-Bronze by itself is not as good of a conductor like copper, but when plated will perform equally well. Phos-Bronze has the ability to retain tension, basically like a spring. I choose high pressure contacts. You can understand the tension I’m referring to by pulling any connector within the bird that utilizes the three wire patch cord also known as a Servo Cable. These are high pressure for a reason, why the GPS cable wasn’t like this from the beginning I don’t understand… Again an example photo is listed below.
First option (A) is to use the existing male connector on the main board. The NEW female plug has a locking tab that interlocks with the board’s male housing. The female connector pins will need to be replaced. I chose to buy a specific tool to crimp these connectors, but you may find equal results using a pair of pliers – that is your choice rather than my recommendation.
Second option (B) was to replace the male connector on the board with a known better quality. I chose not to use the locking tab, instead went with a detent design for both the plug and housing to ease removal. Same female connectors however. The fit was much better between the two parts, plug and housing.
All parts sourced were Tyco Electronics aka TE. I’m sure you can find an equal to TE, use the part number provided to give you some guidance. Also I purchased from MOUSER, again 1 day shipping to me so they’re the best. More detail spec’s offered in the links provided.
OPTION A $2.25
104257-3 Headers & Wire Housings RECEPTACLE ASSY 4P
102128-1 Headers & Wire Housings RECPT CONTACT 26-22
OPTION B $3.50
5-103414-2 Headers & Wire Housings SHROUDED VERT SNGL 4 with standoffs
102241-2 Headers & Wire Housings POLARIZED HSG 4P detent latching
102128-1 Headers & Wire Housings RECPT CONTACT 26-22
For me, I’m choosing Option B. The MOLEX offering by vk3bq previously is obviously a better choice since it was intended for the vibrating environment. Also the contact cleaner suggestion was outstanding by copyhere. Both suggestion were valuable contributions that should be explored further by others as viable solutions.
I purchased the crimping tool from Hansen RC, there are other that may be better….Engineer Inc. has another option that I liked. EDIT to add: The Hansen version crimper works well. The ability to adjust tool's tension works very well for the variety of connectors I will be able to crimp with it here after.
And finally, I have not implemented the MOD on my bird yet. I'm at 100% for all functions, GPS count, FPV transmission and no GPS loss while recording. Life has gotten in the way since baseball season has arrived for my son. So I'll do the MOD once I have the time or a failure.
Good luck. Attempt at your own risk, no warranty implied.
Let’s talk connectors first, the little copper crimp pins inside the plastic plugs. DJI’s offering had very low tension. Either vibration or several removals from the plug allows the contact fingers to lose tension. Basically deforming to allow a poor contact to the male pin on the main board. Further DJI’s appear to be of copper only, no plating on the contact fingers. Bare copper will corrode.
Further, plain copper does not have a great ability to have strength from bending. Bend it enough and it will break or deform out of the way. I bought an RC dealers variation for the items below and had the female pins lose tension after a couple installations, much like the DJI. Those will end up as practice connectors and are shown below as a further example.
I choose a Phosphorus Bronze connector that was gold plated. Phos-Bronze by itself is not as good of a conductor like copper, but when plated will perform equally well. Phos-Bronze has the ability to retain tension, basically like a spring. I choose high pressure contacts. You can understand the tension I’m referring to by pulling any connector within the bird that utilizes the three wire patch cord also known as a Servo Cable. These are high pressure for a reason, why the GPS cable wasn’t like this from the beginning I don’t understand… Again an example photo is listed below.
First option (A) is to use the existing male connector on the main board. The NEW female plug has a locking tab that interlocks with the board’s male housing. The female connector pins will need to be replaced. I chose to buy a specific tool to crimp these connectors, but you may find equal results using a pair of pliers – that is your choice rather than my recommendation.
Second option (B) was to replace the male connector on the board with a known better quality. I chose not to use the locking tab, instead went with a detent design for both the plug and housing to ease removal. Same female connectors however. The fit was much better between the two parts, plug and housing.
All parts sourced were Tyco Electronics aka TE. I’m sure you can find an equal to TE, use the part number provided to give you some guidance. Also I purchased from MOUSER, again 1 day shipping to me so they’re the best. More detail spec’s offered in the links provided.
OPTION A $2.25
104257-3 Headers & Wire Housings RECEPTACLE ASSY 4P
102128-1 Headers & Wire Housings RECPT CONTACT 26-22
OPTION B $3.50
5-103414-2 Headers & Wire Housings SHROUDED VERT SNGL 4 with standoffs
102241-2 Headers & Wire Housings POLARIZED HSG 4P detent latching
102128-1 Headers & Wire Housings RECPT CONTACT 26-22
For me, I’m choosing Option B. The MOLEX offering by vk3bq previously is obviously a better choice since it was intended for the vibrating environment. Also the contact cleaner suggestion was outstanding by copyhere. Both suggestion were valuable contributions that should be explored further by others as viable solutions.
I purchased the crimping tool from Hansen RC, there are other that may be better….Engineer Inc. has another option that I liked. EDIT to add: The Hansen version crimper works well. The ability to adjust tool's tension works very well for the variety of connectors I will be able to crimp with it here after.
And finally, I have not implemented the MOD on my bird yet. I'm at 100% for all functions, GPS count, FPV transmission and no GPS loss while recording. Life has gotten in the way since baseball season has arrived for my son. So I'll do the MOD once I have the time or a failure.
Good luck. Attempt at your own risk, no warranty implied.
Attachments
Thanks RichWest and as you promised worth the wait....
I'll be ordering today!
Next weekend to do: Rebuild GPS unit w/ Antenna upgrade, connector changeout and FLY!!!!!!!!!!!
I'll be ordering today!
Next weekend to do: Rebuild GPS unit w/ Antenna upgrade, connector changeout and FLY!!!!!!!!!!!
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Though the connector is a rather sloppy fit in the socket I am not sure replacing one or both is the right way forward.
First off it will NOT come out as the top shell will prevent this.
Unsoldering the socket and putting a new one on is a possible source of disaster with the main PCB.
Plus you have to take the whole lot apart as well.
Bending the pins a fraction and put a 5mm strip of velcro on the back of the plug to increase the force needed to extract the plug is the easiest and simplest least risk way forward. Also takes 2 minutes to do this from start to finish.
First off it will NOT come out as the top shell will prevent this.
Unsoldering the socket and putting a new one on is a possible source of disaster with the main PCB.
Plus you have to take the whole lot apart as well.
Bending the pins a fraction and put a 5mm strip of velcro on the back of the plug to increase the force needed to extract the plug is the easiest and simplest least risk way forward. Also takes 2 minutes to do this from start to finish.
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RichWest, I appreciate your time and effort. It's always nice to have as many options possible. As of now I think I will look into replacing the plug, and leaving the receiving connector on the board alone other then using the mentioned contact cleaner.
Robin - Can't disagree with your thinking, but there are a few that would like other OPTIONS. YMMV
Prylar - Again another great post, DUH
Frank - The female connector pins were sourced to allow either Option (A or B) to be interchangeable without changing the pins. An upgrade path if you will.
The focus shouldn't be specifically on the Options offered, the plastic plug style. The main point is the female contact pins themselves. The end results was to source a better connector. The default receptacle on the main board was the limiting factor, I had to find something that would fit properly. Option B, for those that wanted a mated solution, was the best option considering the board's configuration.
Further, the offering does not imply you'll receive better reception with your GPS. Nor will it resolve other known issues like "fly away's". But it will eliminate a short coming for the stock connector from DJI. One less factor, so that we can find a final solution to these issues. My little contribution to the members, free of charge btw...
Prylar - Again another great post, DUH
Frank - The female connector pins were sourced to allow either Option (A or B) to be interchangeable without changing the pins. An upgrade path if you will.
The focus shouldn't be specifically on the Options offered, the plastic plug style. The main point is the female contact pins themselves. The end results was to source a better connector. The default receptacle on the main board was the limiting factor, I had to find something that would fit properly. Option B, for those that wanted a mated solution, was the best option considering the board's configuration.
Further, the offering does not imply you'll receive better reception with your GPS. Nor will it resolve other known issues like "fly away's". But it will eliminate a short coming for the stock connector from DJI. One less factor, so that we can find a final solution to these issues. My little contribution to the members, free of charge btw...
Thanks Rich for the research. My contact cleaner fix did not last. today my phantom had the original problem back again slow flashing yellow light with no satellites. the new connectors will be a permanent fix. I'm just glad it failed before taking off and not while in the air. The people looking for a simple solution should realize that the problem is not that the connector can come off because it is loose, but the pins are such low quality that the contact can be lost with it in place. I would recommend at the minimum doing solution A. you do not want to lose gps in the air if you have to use home lock or failsafe.
Excellent Job Rich. The extra work and accurately definitive solution is much appreciated!RichWest said:
