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Inspire 1v2 Aircraft's TX/RX weak signal, ncore problem

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Hello,

Some time ago I have measured the aircraft antennas power output using spectrum analyzer and I've got big difference between left motors -4.0 dBm and right motors -17.0 dBm. I was wondering that this could be a cold solder or damaged antenna cable or connector but decided to switch the cables where they connect to the ncore and the result was that the weak antennas become strong and vise versa. So it looks that the ncore itself is outputing 2 channels at -17 dBm and the other two at -4 dBm and there is no problem with the cables or the antennas themselves.

I've found the published FCC tests for inspire 1v2 and there all four antennas are emitting relatively eaqual power in all test conditions, so there is definitelly a problem within the ncore.

Does anyone had similar issue and probably replaced the ncore to fix this? Could this be the ncore connectors only or the transmiter inside the ncore is gone? Any thoughts?
 
There is no problem with the nCore. It is the firmware.

v01.11.x.x completely kills the transmission power of ALL versions of the nCore. This is well documented and known.

You do run a risk of trying to downgrade a T601 nCore to v01.08.x.x/v01.09.x.x which is the BEST version to run for transmission distance. DJI actually has released no less than 3 different v01.08.x.x/v01.9.x.x firmwares in an attempt to keep people from downgrading. If you get a "bad" version, it can brick the aircraft.

I actually have 3 versions of v01.10.x.x, and yes, one will brick a T601 on downgrade. I do not have all 3 versions of the other firmware versions.

All I *CAN* say is find a copy of the earlier firmware from one of the repositories available online. They will have a "good" version you *CAN* downgrade to.

The issue is that DJI modifies the firmware on their own site for distribution. On the previously mentioned v01.10.x.x, the ORIGINAL release has a radio module that is the same as the v01.08.x.x revision. The latest v01.10.x.x has the SAME radio module as v01.11.x.x. There is an interim version of v01.10.x.x that has a interim radio module not in v01.08.x.x or in v01.11.x.x.

Basically there are various firmware files published to handle various hardware (v01.08.x.x is for use with x3/x5 camera updates for example, and v01.09.x.x is for use with Z3 cameras for example), and while they just won't "up-rev" everything to say a v01.11.x.x for EVERYTHING, they will go back and change firmware with newer modules to force everyone onto what they want them to run.

Just like if you download v01.09.x.x directly from DJI, it will contain almost all the same modules as v01.11.x.x.
 
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There is no problem with the nCore. It is the firmware.

v01.11.x.x completely kills the transmission power of ALL versions of the nCore. This is well documented and known.

You do run a risk of trying to downgrade a T601 nCore to v01.08.x.x/v01.09.x.x which is the BEST version to run for transmission distance. DJI actually has released no less than 3 different v01.08.x.x/v01.9.x.x firmwares in an attempt to keep people from downgrading. If you get a "bad" version, it can brick the aircraft.

I actually have 3 versions of v01.10.x.x, and yes, one will brick a T601 on downgrade. I do not have all 3 versions of the other firmware versions.

All I *CAN* say is find a copy of the earlier firmware from one of the repositories available online. They will have a "good" version you *CAN* downgrade to.

The issue is that DJI modifies the firmware on their own site for distribution. On the previously mentioned v01.10.x.x, the ORIGINAL release has a radio module that is the same as the v01.08.x.x revision. The latest v01.10.x.x has the SAME radio module as v01.11.x.x. There is an interim version of v01.10.x.x that has a interim radio module not in v01.08.x.x or in v01.11.x.x.

Basically there are various firmware files published to handle various hardware (v01.08.x.x is for use with x3/x5 camera updates for example, and v01.09.x.x is for use with Z3 cameras for example), and while they just won't "up-rev" everything to say a v01.11.x.x for EVERYTHING, they will go back and change firmware with newer modules to force everyone onto what they want them to run.

Just like if you download v01.09.x.x directly from DJI, it will contain almost all the same modules as v01.11.x.x.
Intersting. So there are "clean" and "dirty" versions of v1.08.xx and v1.09.xx?

For whatever reason, the panorobot site went down a while ago, which was my goto site for Inspire 1 FW. So far I haven't been able to find a replacement host, but I honestly haven't looked in months. Have you had any luck finding earlier versions of the firmware in the public domain?

D
 
Intersting. So there are "clean" and "dirty" versions of v1.08.xx and v1.09.xx?

For whatever reason, the panorobot site went down a while ago, which was my goto site for Inspire 1 FW. So far I haven't been able to find a replacement host, but I honestly haven't looked in months. Have you had any luck finding earlier versions of the firmware in the public domain?

D
Yeah, there are a few "hacker friendly" repositories out there. Since they are nestled away and a total PITA to find I will send you a PM with the links. Sorry to everyone else, but I figure if they get hit with a ton of traffic they will disappear too.

In regards to v1.8.xx and v1.9.xx, both have been published elsewhere by DJI as supported links under certain cameras and devices, but I have verified by disassembling the firmware that the modules in them are from v01.11.x.x. So they are NOT v1.8.x.x/v1.9,x,x but v1.11.x.x in disguise with just very specific modules for certain devices.

As I mentioned, I have a full copy of the ORIGINAL v1.10.x.x and it has versions of 2 or 3 modules that I cannot find in ANY other v1.10.x.x firmware versions I have found.
 
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There is no problem with the nCore. It is the firmware.

v01.11.x.x completely kills the transmission power of ALL versions of the nCore. This is well documented and known.

You do run a risk of trying to downgrade a T601 nCore to v01.08.x.x/v01.09.x.x which is the BEST version to run for transmission distance. DJI actually has released no less than 3 different v01.08.x.x/v01.9.x.x firmwares in an attempt to keep people from downgrading. If you get a "bad" version, it can brick the aircraft.

I actually have 3 versions of v01.10.x.x, and yes, one will brick a T601 on downgrade. I do not have all 3 versions of the other firmware versions.

All I *CAN* say is find a copy of the earlier firmware from one of the repositories available online. They will have a "good" version you *CAN* downgrade to.

The issue is that DJI modifies the firmware on their own site for distribution. On the previously mentioned v01.10.x.x, the ORIGINAL release has a radio module that is the same as the v01.08.x.x revision. The latest v01.10.x.x has the SAME radio module as v01.11.x.x. There is an interim version of v01.10.x.x that has a interim radio module not in v01.08.x.x or in v01.11.x.x.

Basically there are various firmware files published to handle various hardware (v01.08.x.x is for use with x3/x5 camera updates for example, and v01.09.x.x is for use with Z3 cameras for example), and while they just won't "up-rev" everything to say a v01.11.x.x for EVERYTHING, they will go back and change firmware with newer modules to force everyone onto what they want them to run.

Just like if you download v01.09.x.x directly from DJI, it will contain almost all the same modules as v01.11.x.x.
Thanks for the reply! In my opinion this is nothing to do with the latest firmware. The firmwares above 1.09 (if I'm not mistaken) are reducing the power equaly on all antennas otheriwse it doesn't make sense.

About the downgrade, I've been there and did that long time ago but I didn't like the result as the 1.08 have other issues/limitations when used with the x5r camera, can't remember all the details as it was about 2 years ago but I had to go a little up to 1.08.01.40 to fix some of the issues like not remembering the camera settings (frame rate) after reboot also with this firmware the focus expansion module cannot be used and there where other issues with osmo RAW and the usb/can extension cable.

But as you mentioned firmware it just came to me to try to reinstall the latest firmware which I assume involves downgrading at first place. Do you know if there is a way to refresh the firmware without downgrading first?
 
Have you had any luck finding earlier versions of the firmware in the public domain?
Some time ago I've saved those links for the Inspire RAW, they still work so I suppose DJI keeps the firmwares on their servers for X3 and X5 as well.

 
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Again, those firmware are all basically the same radio modules. If it is off a DJI server they already "hacked" their own firmware to force the modules they want everyone on.

It may have camera or other modules that are lower revs, but the radio modules are not. If you decompile the firmware you will see what versions are included. I was VERY disappointed to see they went that route, as most companies leave firmware revs as "locked history". DJI is NOT that kind of company.
 
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So I've downgraded to 1.08.01.20 and the problem still persist, the antennas on the starboard side measure much weaker than those on the port side. Actually there is no difference in the measured dBm between fw 1.11 and 1.08. The file I have for 1.08.01.20 was downloaded back in January 2018.
 
Well, if you are convinced that the nCore is the problem, by all means replace it.

Just do the same tests with the replacement nCore. I would be surprised if they weren't the same as before the replacement.

And, quite frankly, if they are different after the replacement, it would be great for the rest of us to know that.

Personally, I think you are seeing different values based on the different frequencies being transmitted on each antenna. The Inspire 1 uses BOTH 2.4Ghz and 5.8Ghz to transmit and receive.

From the specs:
EIRP10 dBm@900m MHz, 13 [email protected] GHz, 20 [email protected] GHz

So 2.4Ghz transmits at a MUCH higher power level than 5.8Ghz does (900Mhz is for Japan only, so it is ignored).

The respective frequencies do not "share" an antenna on the aircraft. Only the remote controller shares an antenna and that is ONLY when doing Master/Slave communications BETWEEN the controllers. That is why the GL658C tanks on later firmware between controllers, as they dial down the transmission power for the video feed on those later revisions which is hard to receive on the Slave controller due to the shared nature of the one antenna. Again, all of this is well documented by plenty of people on here. Donnie Frank has also posted a number of videos talking about the failed video reception on later firmware revisions.

Also, to clarify, even if you downloaded the v01.08.x.x firmware in 2018, it is the same radio module as v01.11.01.50 that was released back in 2017. So of course it would have the EXACT same power levels. That is why I pointed out several times that you CANNOT trust the firmware off DJI servers for older versions as they are "hacked" to include the later radio modules. The revision will come back as an older revision in SOME of the firmwares, but upon inspection they are the SAME module as the later revision firmware. Again (and for the last time), DJI is forcing people to run the radio modules they want you to run. The ONLY way to run an older revision is to find an older repository with that older revision.

If you look at the firmware threads on here, there have been some very in-depth dissections of the firmware revisions and what they do and why.

FACT: DJI reduced power on the Inspire 1 with v01.10.x.x and above. ALL firmware posted by DJI AFTER v01.11.x.x came out were modified to include the radio modules from v01.11.x.x (so even revs as old as v01.06.x.x have the v01.11.x.x radio modules). Going by revisions posted during the logfile created during the update is insufficient, as you must get the checksum of the module loaded to see EXACTLY what was loaded. There are interim firmwares posted by DJI that included the actual v01.11.x.x versions in a v01.08.x.x firmware image. DJI went back and remodified it so that the module reported an earlier version, yet the checksum still proves it is the later version.

Again, I personally have done all this work trying to track down the stupidity with DJI firmware. DJI does not care about engineering standards, best-practices, or anything else. They will publish what they want, how they want and do not consider the end-user in any way shape or form, outside of "you will run what we want you to run". Just look at how many people have bricked cameras with firmware updates. That happened because they changed hardware in cameras and never went back in and re-rolled firmware to include those changes, so if you do an update to one of those newer cameras, you WILL brick it. DJI knows this and that is why they have been replacing cameras ON THEIR DIME! It is not "good customer service", but if they did not (and I am sure that will come to an end somewhere here) I am sure they would get sued since it happens far too often. Personally I just got back a few months ago a X5 camera that had the same thing happen. I WILL NOT use that camera to do a firmware update. Actually, I use a MUCH older camera to do all my updates, one that actually WON'T take the firmware update itself (yeah, yeah, I found some loopholes on how the firmware works in all my research) and thus I am not risking anything by using that camera in ANY of my Inspire 1 setups to handle firmware updates.

No-one is trying to tell you that you are wrong. We are posting up the technical information so that you can succeed in whatever problem you have. Do I have a RF power meter? No. Do I care to spend money on one, no. But until you post up the issues you have been having and can verify that you, in fact, have found a problem, posting up an "assumed" issue and then arguing some facts that some of us know are already flawed (like firmware off DJI servers) is only going to create even more issues, as people, in general, a extremely lazy creatures and will read you post and make the *assumption* that their problem is the same.

So, to pose the "real" question: Do you have any issues with your Inspire 1? Is it a "range" issue? Is it a "video signal" issue?

See, the later two parts of that query are already known. Firmware v01.10.x.x and later have reduced power radio modules. They also have totally changed flight restriction and geo-fencing modules.

What you describe as "issues" with older vs newer firmware are actually partially dealt with in the cameras themselves. I have personally found that running the v01.08.x.x/v01.9.x.x aircraft firmware with the latest v01.11.x.x CAMERA firmware results in the best options overall. The cameras are "fixed" with the latest firmware and the aircraft is running an unrestricted radio firmware. You must ALSO pair the aircraft firmware with the proper controller firmware (which you state will cause a cable-connected DJI Focus to have issues, but personally I have found a RF-Slave connected DJI Focus, via the Focus Expander, does not).

So, ultimately, I think the BIG issue here is that you want to run the "latest and greatest" that DJI offers. Go right ahead. You will have reduced power and range. Your reasons are you reasons. No one is arguing that. But, *I* highly doubt anything you are seeing is "out of the ordinary" and would really like to hear if a swapped nCore would produce different results. Just be sure to reflash the latest v01.11.x.x firmware to the nCore after it is replaced so it is an apples-to-apples comparison.
 
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Well, if you are convinced that the nCore is the problem, by all means replace it.

Just do the same tests with the replacement nCore. I would be surprised if they weren't the same as before the replacement.

And, quite frankly, if they are different after the replacement, it would be great for the rest of us to know that.

Personally, I think you are seeing different values based on the different frequencies being transmitted on each antenna. The Inspire 1 uses BOTH 2.4Ghz and 5.8Ghz to transmit and receive.

From the specs:
EIRP10 dBm@900m MHz, 13 [email protected] GHz, 20 [email protected] GHz

So 2.4Ghz transmits at a MUCH higher power level than 5.8Ghz does (900Mhz is for Japan only, so it is ignored).

The respective frequencies do not "share" an antenna on the aircraft. Only the remote controller shares an antenna and that is ONLY when doing Master/Slave communications BETWEEN the controllers. That is why the GL658C tanks on later firmware between controllers, as they dial down the transmission power for the video feed on those later revisions which is hard to receive on the Slave controller due to the shared nature of the one antenna. Again, all of this is well documented by plenty of people on here. Donnie Frank has also posted a number of videos talking about the failed video reception on later firmware revisions.

Also, to clarify, even if you downloaded the v01.08.x.x firmware in 2018, it is the same radio module as v01.11.01.50 that was released back in 2017. So of course it would have the EXACT same power levels. That is why I pointed out several times that you CANNOT trust the firmware off DJI servers for older versions as they are "hacked" to include the later radio modules. The revision will come back as an older revision in SOME of the firmwares, but upon inspection they are the SAME module as the later revision firmware. Again (and for the last time), DJI is forcing people to run the radio modules they want you to run. The ONLY way to run an older revision is to find an older repository with that older revision.

If you look at the firmware threads on here, there have been some very in-depth dissections of the firmware revisions and what they do and why.

FACT: DJI reduced power on the Inspire 1 with v01.10.x.x and above. ALL firmware posted by DJI AFTER v01.11.x.x came out were modified to include the radio modules from v01.11.x.x (so even revs as old as v01.06.x.x have the v01.11.x.x radio modules). Going by revisions posted during the logfile created during the update is insufficient, as you must get the checksum of the module loaded to see EXACTLY what was loaded. There are interim firmwares posted by DJI that included the actual v01.11.x.x versions in a v01.08.x.x firmware image. DJI went back and remodified it so that the module reported an earlier version, yet the checksum still proves it is the later version.

Again, I personally have done all this work trying to track down the stupidity with DJI firmware. DJI does not care about engineering standards, best-practices, or anything else. They will publish what they want, how they want and do not consider the end-user in any way shape or form, outside of "you will run what we want you to run". Just look at how many people have bricked cameras with firmware updates. That happened because they changed hardware in cameras and never went back in and re-rolled firmware to include those changes, so if you do an update to one of those newer cameras, you WILL brick it. DJI knows this and that is why they have been replacing cameras ON THEIR DIME! It is not "good customer service", but if they did not (and I am sure that will come to an end somewhere here) I am sure they would get sued since it happens far too often. Personally I just got back a few months ago a X5 camera that had the same thing happen. I WILL NOT use that camera to do a firmware update. Actually, I use a MUCH older camera to do all my updates, one that actually WON'T take the firmware update itself (yeah, yeah, I found some loopholes on how the firmware works in all my research) and thus I am not risking anything by using that camera in ANY of my Inspire 1 setups to handle firmware updates.

No-one is trying to tell you that you are wrong. We are posting up the technical information so that you can succeed in whatever problem you have. Do I have a RF power meter? No. Do I care to spend money on one, no. But until you post up the issues you have been having and can verify that you, in fact, have found a problem, posting up an "assumed" issue and then arguing some facts that some of us know are already flawed (like firmware off DJI servers) is only going to create even more issues, as people, in general, a extremely lazy creatures and will read you post and make the *assumption* that their problem is the same.

So, to pose the "real" question: Do you have any issues with your Inspire 1? Is it a "range" issue? Is it a "video signal" issue?

See, the later two parts of that query are already known. Firmware v01.10.x.x and later have reduced power radio modules. They also have totally changed flight restriction and geo-fencing modules.

What you describe as "issues" with older vs newer firmware are actually partially dealt with in the cameras themselves. I have personally found that running the v01.08.x.x/v01.9.x.x aircraft firmware with the latest v01.11.x.x CAMERA firmware results in the best options overall. The cameras are "fixed" with the latest firmware and the aircraft is running an unrestricted radio firmware. You must ALSO pair the aircraft firmware with the proper controller firmware (which you state will cause a cable-connected DJI Focus to have issues, but personally I have found a RF-Slave connected DJI Focus, via the Focus Expander, does not).

So, ultimately, I think the BIG issue here is that you want to run the "latest and greatest" that DJI offers. Go right ahead. You will have reduced power and range. Your reasons are you reasons. No one is arguing that. But, *I* highly doubt anything you are seeing is "out of the ordinary" and would really like to hear if a swapped nCore would produce different results. Just be sure to reflash the latest v01.11.x.x firmware to the nCore after it is replaced so it is an apples-to-apples comparison.
The aircraft operate only on 2.4Ghz, 5.8Ghz is between the remotes for master/slave control. This can be checked in the FCC test data, all tests on the bird are in 2.4Ghz bandwith. On the FCC test report for the remote are tested both frequencies 2.4 and 5.8.

It's not a range issue, some times I'm getting complete signal loss at 5 meters (rarely) when the inspire's starboard side is facing agains the remote. Otherwise I can go 2km and more away with perfect signal while inspire's back or front or port side is facing the remote. As soon I yaw it so the starboard looks toward the remote the signal is lost. Of course it depend on a few more things like altitude and terrain but overall it looses signal as soon the port side antennas are obscured by inspire's body.

The most interesting thing with the downgrading was that after that the inspire was still bind to the remote but the remote wasn't downgraded I kept it on the latest firmware because my intention was to simply refresh the latest firmware which didn't help unfortunatelly.

So the only option I have now is to call dji support as I can't find ncore for T601 on europe's ebay, There was one in UK that was described as for v2 Pro and another in USA and it's kind of overprised on top of that will have to deal with customs... So right now I'm really cofused how to proceed, our local shops are no no and sending the bird to Germany will cost me a fortune :confused: Will leave it for a few days till make a decision.
 
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So I've replaced the ncore with one from ebay, it came with the latest firmware on it and after measuring the emission gain there is no difference from the replaced one. The antennas on the left motors are still at -5 dBm and the right ones are -17 dBm, exactly like the original ncore measurements. So it turns out this is a function of the drone itself and not a hardware problem.

Is it caused by latest firmwares? Probably yes, if we take into account the official FCC measurings posted above where all four antennas deliver equal emission gain. Why only the right motors, only DJI should know... interesting strategy.

So to improve the overal performance I decided to simply swap two of the antenna cables so to have one strong emission on the left side and one on the right. Have not tested this approach out on the field yet.
 
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So I've replaced the ncore with one from ebay, it came with the latest firmware on it and after measuring the emission gain there is no difference from the replaced one. The antennas on the left motors are still at -5 dBm and the right ones are -17 dBm, exactly like the original ncore measurements. So it turns out this is a function of the drone itself and not a hardware problem.

Is it caused by latest firmwares? Probably yes, if we take into account the official FCC measurings posted above where all four antennas deliver equal emission gain. Why only the right motors, only DJI should know... interesting strategy.

So to improve the overal performance I decided to simply swap two of the antenna cables so to have one strong emission on the left side and one on the right. Have not tested this approach out on the field yet.
What were the results of this test?

D
 
I've measured RF power from different I1 crafts, on both 1.11 and 1.08 firmwares, and they all show the above; more power from left side pairs. Here's an idea: I1 is transmitting from left side pairs, receiving from right side pairs. If RF power is measured with an antenna instead of direct contact, right side low power might simply "leaking" from the left side.
 
A quick update, crossing the antennas is much better. I've had several flights at location where always had poor signal and loosing video in 98% on that spot, sometimes even RTH was auto enabled. Now there is solid connection while the dro e is on that spot. Previously we were turnig off our mobiles and etc. to keep the connection, now it is not necessary.
The swap could be easily done by change antenna connections on the nCore.
 
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