[hwh]

Those dumps show that even though your gps is the same hardware as mine the firmware is different.  Normally DJI gps data is lightly encrypted with a key that's sent in the message.  The key changes constantly.  Your dumps the key is a constant zero.  It looks like someone wrote their own clone firmware instead of using Pawelsky's firmware.

Even so, the data shows that it's sending 0 longitude, 0 latitude constantly, no lock.  It still seems like the hardware is bad because of that and the fact that you're not getting the blue led blinking.  I suggest returning it if you can.

I've ordered one to look at using the link you posted.  It was really strange ordering on a site in a language I can't read.  Fortunately once I got to checkout it switched from Dutch (?)  to English because I was logged in to my account with them.

[Jhinta]

ik thing the ublox is just not good ,, i have connected ublox on arduino again and openup u-center and all i can get is this,

Code: [Select]

22:25:32  R -> UNKNOWN ???,  Size  38,  'UNKNOWN'
22:25:32  R -> NMEA GPGSV,  Size  18,  'GNSS Satellites in View'
22:25:32  R -> UNKNOWN ???,  Size  29,  'UNKNOWN'
22:25:32  R -> NMEA GNVTG,  Size  21,  'Course Over Ground and Ground Speed'
22:25:32  R -> NMEA GNGGA,  Size  33,  'Global Positioning System Fix Data'
22:25:32  R -> NMEA GNGSA,  Size  45,  'GNSS DOP and Active Satellites'
22:25:32  R -> NMEA GNGSA,  Size  45,  'GNSS DOP and Active Satellites'
22:25:32  R -> NMEA GPGSV,  Size  18,  'GNSS Satellites in View'
22:25:32  R -> NMEA GLGSV,  Size  18,  'GNSS Satellites in View'
22:25:32  R -> NMEA GNGLL,  Size  20,  'Geographic Position - Latitude/Longitude'
22:25:32  R -> NMEA GNTXT,  Size  33,  'Text Transmission'
22:25:32  R -> UBX MON-VER,  Size 108,  'Version'
22:25:32  R -> NMEA GNRMC,  Size  25,  'Recommended Minimum Specific GNSS Data'
22:25:32  R -> NMEA GNVTG,  Size  21,  'Course Over Ground and Ground Speed'
22:25:32  R -> NMEA GNGGA,  Size  33,  'Global Positioning System Fix Data'
22:25:32  R -> NMEA GNGSA,  Size  45,  'GNSS DOP and Active Satellites'
22:25:32  R -> NMEA GNGSA,  Size  45,  'GNSS DOP and Active Satellites'
22:25:32  R -> NMEA GPGSV,  Size  18,  'GNSS Satellites in View'
22:25:32  R -> NMEA GLGSV,  Size  18,  'GNSS Satellites in View'
22:25:32  R -> UNKNOWN ???,  Size  52,  'UNKNOWN'
22:25:32  R -> UBX ACK-ACK,  Size  10,  'Acknowledged'
22:25:32  R -> UNKNOWN ???,  Size  38,  'UNKNOWN'
22:25:32  R -> UBX ACK-ACK,  Size  10,  'Acknowledged'
22:25:32  R -> NMEA GNTXT,  Size  31,  'Text Transmission'
22:25:32  R -> NMEA GNRMC,  Size  25,  'Recommended Minimum Specific GNSS Data'
22:25:32  R -> NMEA GNVTG,  Size  21,  'Course Over Ground and Ground Speed'
22:25:32  R -> NMEA GNGGA,  Size  33,  'Global Positioning System Fix Data'
22:25:32  R -> NMEA GNGSA,  Size  45,  'GNSS DOP and Active Satellites'
22:25:32  R -> NMEA GNGSA,  Size  45,  'GNSS DOP and Active Satellites'
22:25:32  R -> NMEA GPGSV,  Size  18,  'GNSS Satellites in View'
22:25:32  R -> NMEA GLGSV,  Size  18,  'GNSS Satellites in View'
22:25:32  R -> NMEA GNGLL,  Size  20,  'Geographic Position - Latitude/Longitude'
22:25:32  R -> NMEA GNTXT,  Size  35,  'Text Transmission'
then it just stops ,, even if i do cold restart it does nothing

[Jhinta]

Those dumps show that even though your gps is the same hardware as mine the firmware is different.  Normally DJI gps data is lightly encrypted with a key that's sent in the message.  The key changes constantly.  Your dumps the key is a constant zero.  It looks like someone wrote their own clone firmware instead of using Pawelsky's firmware.

Even so, the data shows that it's sending 0 longitude, 0 latitude constantly, no lock.  It still seems like the hardware is bad because of that and the fact that you're not getting the blue led blinking.  I suggest returning it if you can.

I've ordered one to look at using the link you posted.  It was really strange ordering on a site in a language I can't read.  Fortunately once I got to checkout it switched from Dutch (?)  to English because I was logged in to my account with them.

  , btw sould , desolder ublox be the same? lets say the one we use for gps+i2c ?
so desolder and swap., sould work right? or firmware related? its the same hardware

[hwh]

I'm getting the idea you can't or don't want to return it. 

As long as it's another M8N module it should be ok to swap it.  There are some minor pin differences between the M8N and earlier 7 or 6 series modules, I don't remember exactly what the difference is.

Before I'd swap modules I'd try jumpering past the LNA and SAW filter in case anything in that signal chain is bad.  One of them bad could make the GPS not see any satellites.  See the attached picture.  Also inspect the ceramic antenna on the other side of the board, if it's cracked the GPS would have the same problem.

[Jhinta]

Yep that made it work triple tested. Removing cable same problem. Wat is the effect of bypassing the filters ?

Verstuurd vanaf mijn LG-D855 met Tapatalk

[hwh]

It makes it a little less sensitive to weak signals but mostly it removes protection from interference by other signals.  The GPS signal is sometimes interfered with by wifi or cell phone signals.  It's not always necessary, a lot of the GPS units don't have the saw filter or external lna chips.   The lna is mostly there to make up for the loss in the saw filter but gives some additional gain.

If it sees enough sats and works you could probably just leave the jumper installed.

[hwh]

this is what i have
http://nl.aliexpress.com/item/NEO-M8N-GPS-Compass-for-DJI-Naza-M-V2-Lite-Flight-Controller-with-Stand/32653889296.html?isOrig=true#extend

I ordered one of these through that link and it arrived today.  It's defective the same as your GPS is, it doesn't see any satellites.  Like yours, not even one satellite to read the time from.

I have another one that looks identical that I had purchased a few months ago.  If I put them side by side and swap cables the older one gets the time in less than 30 seconds and a 4 sat initial lock in about 4 minutes.  The new one never gets even the time after 30 minutes.

I'm going to dig into it a little more and see if I can figure out exactly what in the LNA/SAW filter chain is bad.

[Jhinta]

this is what i have
http://nl.aliexpress.com/item/NEO-M8N-GPS-Compass-for-DJI-Naza-M-V2-Lite-Flight-Controller-with-Stand/32653889296.html?isOrig=true#extend

I ordered one of these through that link and it arrived today.  It's defective the same as your GPS is, it doesn't see any satellites.  Like yours, not even one satellite to read the time from.

I have another one that looks identical that I had purchased a few months ago.  If I put them side by side and swap cables the older one gets the time in less than 30 seconds and a 4 sat initial lock in about 4 minutes.  The new one never gets even the time after 30 minutes.

I'm going to dig into it a little more and see if I can figure out exactly what in the LNA/SAW filter chain is bad.

Nice to know. Im still waiting for my motors

Verstuurd vanaf mijn LG-D855 met Tapatalk

[zebu]

this is what i have
http://nl.aliexpress.com/item/NEO-M8N-GPS-Compass-for-DJI-Naza-M-V2-Lite-Flight-Controller-with-Stand/32653889296.html?isOrig=true#extend

I ordered one of these through that link and it arrived today.  It's defective the same as your GPS is, it doesn't see any satellites.  Like yours, not even one satellite to read the time from.

I have another one that looks identical that I had purchased a few months ago.  If I put them side by side and swap cables the older one gets the time in less than 30 seconds and a 4 sat initial lock in about 4 minutes.  The new one never gets even the time after 30 minutes.

I'm going to dig into it a little more and see if I can figure out exactly what in the LNA/SAW filter chain is bad.

Hello,

Any news about the problem ?

I plan to buy one of these DJI GPS clones, but I prefer one which is working good

[hwh]

Just don't buy it from that particular seller.    Most of the clone DJI/Naza GPS units work fine.  This seller had a batch (or at least two) that were bad.

Even the bad ones work OK if you jumper over the LNA/Saw filter chain, they're just a little less immune to interference.  Many of the GPS units on the market don't even have the LNA/Saw filter.

Since I have way more GPS units than I need I decided to put off fixing this until next Winter when I'm not inclined to go outside anyway.  Exactly what is wrong doesn't matter much to most people since they couldn't replace the tiny parts anyway.

The bottom line is just buy one and see if it works, most work fine. If it doesn't contact the seller, most will work something out.  I ended up taking a 50% refund since I intend to eventually fix it.

The actual DJI brand ones seem to work a little better than the clones (they see a couple more sats for one thing) but the clones seem to work as well as most GPS on the market and still only take up one of the flight controller's ports.  The clones are less than half the price of the DJI brand ones, often closer to a third of the price.

[Jhinta]

this is what i have
http://nl.aliexpress.com/item/NEO-M8N-GPS-Compass-for-DJI-Naza-M-V2-Lite-Flight-Controller-with-Stand/32653889296.html?isOrig=true#extend

I ordered one of these through that link and it arrived today.  It's defective the same as your GPS is, it doesn't see any satellites.  Like yours, not even one satellite to read the time from.

I have another one that looks identical that I had purchased a few months ago.  If I put them side by side and swap cables the older one gets the time in less than 30 seconds and a 4 sat initial lock in about 4 minutes.  The new one never gets even the time after 30 minutes.

I'm going to dig into it a little more and see if I can figure out exactly what in the LNA/SAW filter chain is bad.

Hello,

Any news about the problem ?

I plan to buy one of these DJI GPS clones, but I prefer one which is working good

As above just get from a other seller. but it sould work. Once I have my motors I will report back. ( waiting for months because seller made a error in shipping but my motor are finally shipt correctly) a week or two.

Verstuurd vanaf mijn LG-D855 met Tapatalk

[TheOtherCliff]

I fly a DJI GPS clone all the time on one of my two quads.  Before that, during extensive bench testing I found that this DJI GPS clone has some serious problems.  Note that there is no configuration for it; you just power it on and receive data that it sends.  But it sometimes stops sending GPS data even though the uBlox GPS blue 1PPS LED still blinks (indicating that the uBlox GPS is still working fine and has a good GPS fix).  Sometimes it stops sending all data, even mag data and firmware version.

It drops MANY GPS packets, but that does not really hurt anything.  It drops about 1 GPS packet per second (about 1 out of 5 or 6).  It completely locks up or stops sending GPS packets maybe once every 24 hours of operation.

In flying, it generally does an acceptable job.  Yesterday it started to fly away so I switched to Attitude mode and brought it back.  When I switched back to GPS mode it started to fly away again.  I switched back to Attitude mode, landed, unplugged GPS to power just GPS off, plugged it back in, and the problem was fixed.  This is the first actual flight issue I have had with this DJI GPS clone in probably 30 flights.

I bought this DJI GPS clone version because it was the cheapest one.  Another developer bought a different version and did not have these problems in during multi-day testing.

For anyone buying these DJI GPS/mag clones, I suggest that you connect your quad to an "AC powered" power supply and run it continuously for several days to make sure that it doesn't have problems.  Note that once it stops sending data, it does not recover until you power the DJI GPS clone off and back on, so before powering off, you can simply check at the end of the test to make sure the GPS and mag are still working.  That won't show problems if running motors put noise on your power, but it will find the kinds of problems I have seen with this cheapest clone.

This one looks like the one I bought. but of course it could be better or worse.  Lately there are versions that are even cheaper than this one.
http://www.ebay.com/itm/Ublox-NEO-M8N-GPS-Compass-Support-DJI-Naza-M-V2-Lite-Flight-Controller-FPV-/301931345971

[TheOtherCliff]

$43 (shipped) DJI/Naza Lite GPS

http://www.ebay.com/itm/251862698572

I received mine today.  It's an authentic DJI Naza Lite.  I haven't tested it yet.

You need "next" or the upcoming release to use it, and you must solder a different connector on it.

[jtrout19]

Hey guys so i am contemplating replacing my neo 6 with a naza gps. I dont mind clones just trying to find a high quality clone. Can you guys recommened some sites that sell high quality clones. After reading the issue that can come on with i2c i figure i dont want to use it. So yeah banggood has one for 22 dollars US. What do you guys think. Give me some other option as well.

[TheOtherCliff]

I bought one of the cheapest DJI clone GPSs I could find on eBay.  That one appears to have several problems.  Maybe just one with different symptoms.

There are 3 packet types that are sent at different intervals.  I wrote a program to dump all the data.  You can see that when two packets are scheduled to be sent at the same time, that one overwrites the other and the first packet gets interrupted and the second packet starts in the middle of the first packet.  This happens enough that the GPS packets should be 5 packets per second but you get an average of 4 packets per second.  Also, it completely locks up randomly, maybe once every 24 hours or so.  It works, and as long is GPS is not mission critical it is OK and you just switch to non-GPS mode when it starts to fly away (only happened once to me).

I won't buy one of those again when I can get a real DJI GPS for $39 shipped.  I wrote the DJI GPS driver for LP so I did a lot of testing.  Other people report decent results from clones, but I wonder if they have been tested for days a time.
http://www.ebay.com/itm/DJI-Naza-M-Lite-GPS-Module-with-GPS-Bracket-for-RC-Quadcopter-Multi-rotor-G2T4-/131988064582

Or a complete DJI Naza system for $71.00 shipped.
https://forum.librepilot.org/index.php?topic=2336.msg16552#msg16552