Solo with NEO-M8N Module and 8.3mm Active Patch Antenna Test

[Retired2Fly]

I understand perfectly well what I'm reading, the pull request is particularly clear as are the code changes putting the HDOP checks back into the code since. My posts have been specifically about your assertions only parameter changes were in the firmware, that is wrong, given you can't even admit you're wrong I'd recommend anyone treats anything you say as being misinformed either by lack of knowledge or deliberate intent to troll.

1.05 put in the HDOP check to the pre-arm (along with other changes), with it having been pulled before the Solo was released, 1.05 did not just make parameter changes as you stated.

You keep contradicting yourself over and over. One post you stated HDOP Is just a customary value shown in the solo app for nostalgia purposes and was never actually used. Prior you stated the HDOP check was added with 1.05 even though I know for a fact that solo with 1.0 shipping had a 4.5 and changing it to 2.0 actually prevented solo from a pre-arm in 1.0 until the HDOP just below the new value so once again you are wrong. Then you asserted there is nothing wrong with solo's GPS hardware yet you know state you were here specifically only address my comment about solo's parameter set which you indirectly called Chris a liar as he was the one who made that statement to me. For someone who claims not to be a 3DR employee you certainly seem to know a lot more than their development team and their top management so I take your for "knowledge" for what it is really worth.

I am not the one trolling here . You came into this tread making false statements that 3DR management has already disputed. At this point to save the community the pain of our pointless argument we will just have to agree to disagree and you can stop posting you nonsense and go back to your fantasy world while the rest of us attempt to help make solo a better product..

 

[Ian [P13]]

You've had the pull request posted by a 3DR Dev in this very thread, the HDOP check wasn't in prior to 1.05, I've posted the comment from GitHub explaining why it was put back in. It's little use in flight and was added back as belts and braces to the prearm.

Having GPS on a mount always works well, so this will be an interesting mod to watch regardless, if I was ever to do something similar I'd personally use a 7N as I know the M8N isn't a cure all.

 

[SteveMyers75]

Yes, but have you considered the possibility that moving the antennas will result in a significant enough boost in performance, that it might be all you need to do?

Also on this one.
The stock GPS module as shipped from 3DR doesn't have an external connection port to adapt an external antenna
(Shame on them! This is a development platform. That's why it has an expansion port and is Open Source! We want to control/change anything and everything from the antennas (antenni?) on the Artoo to the antenna on the GPS!)

Also, does anyone know of a NEO-7N module that has a uFL/I-PEX connector port and supports active and passive?

My NEO-M8N has I-PEX, but my NEO-7N is SMA.
I'd like to use exactly the same setup for testing, but it looks like I'll have to swap out the cable ends...not so easy to do out in the dirt M/C park...
If I use a different antenna, even though it's the same brand and model with different cable ends, the test won't be 100% accurate.

One last comment.
When it comes to this sport/hobby, Marco Robustini is my hero.
His videos, like the one that shows him stress-testing the NEO-M8N, are priceless.

The talent he demonstrates like in this one:

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is hands down more impressive than that kid that flew his rig between the Electrical Towers posted elsewhere here. There's no luck involved here.

To me it's like comparing someone who can dance the Tango against someone in a Mosh Pit.

 

[Earldgrayjr]

He is VERY good. I agree. One instance is about taking (unnecessary) risks, a little skill, and a lot of luck. The other was all skill and putting a craft through it's paces.

Of course if I tried to do the latter, it would be highly risky

I am all about the pictures. Nice and slow for me

 

[Earldgrayjr]

There are people far more experienced here than I, but I would bet the GPS issue is going to be a big one, as the Solo is billed to rely on it more heavily than other UAV's in this class.

Is this similar to the isolation design issue they had with P2, where the "workaround" was to install metal foil to provide RF isolation? Just curious if a similar solution might be useful here.

 

[SteveMyers75]

There are people far more experienced here than I, but I would bet the GPS issue is going to be a big one, as the Solo is billed to rely on it more heavily than other UAV's in this class.

Is this similar to the isolation design issue they had with P2, where the "workaround" was to install metal foil to provide RF isolation? Just curious if a similar solution might be useful here.

The stock GPS Module is pretty well covered in Copper RF insulation foil, but there still may be an issue here.
I've ordered up some more 2" wide 3M 1125 Copper-Adhesive backed RF shielding foil from Digikey, and I'm going to add that too.


Today's tests were short lived as the wind speed is 18-20 knots gusting to 26+.
Too much wind for me to feel at ease with the Solo in Manual mode in an emergency.
The wind is supposed to be calm tomorrow so I can do some Props-On tests with the M8N.

We did a lot of props-off testing and found that the antenna is extremely susceptible to placement underneath any of the Solo's plastic parts. (Is there lead inside this China Plastic or what??)

My Wing-man pointed out after we returned that the battery release button looks to be some other plastic than the rest of the battery case, and it has a metal spring so tomorrow we're going to do some tests without it. The internal patch antenna has to go through the Battery Case housing, the Battery Release Button and the snap-on Plastic GPS Cover.

In theory none of these should make a difference, but still I want to know why is there such lousy performance when I mount any patch there.

From the Taoglas Website:
"Close proximity to components or housing affects the electrical performance of all antennas. When placed within the enclosure, in most cases, there should be a clearance of 5mm in all directions from the housing, metal, or other components for maximum efficiency. A reduction in antenna efficiency and a shift in tuned frequency will be observed if these clearances are not maintained. Proximity effects will also have an adverse effect on the radiation pattern of the antenna. Device housings should never be metal or have metal materials when using internal antennas. Also note that some housing colorants, such as carbon black, have RF absorptive properties and can severely degrade antenna performance. Housing materials that absorb moisture, such as nylon, are also not recommended."

Reading this, and seeing that the Solo's GPS Module is mounted with the passive patch antenna pressing directly against the Battery Housing and everything inside is black plastic makes me wonder.

The M8N/Active patch still substantially outperforms the stock 7N when mounted internally, but we ended up ditching the internal mounts in favor of "Clear-Sky" exposed until I can get longer cables for the antennas.

Since I don't yet have the SMA->I-PEX adapter for my 7N module, we relocated the stock Solo 7N module external of all plastic are ran some tests.
I'll tally up a complete breakdown spreadsheet when I'm done, but I can say it didn't do much better external than internal as far as Start - Restart times.

The main issue is acquisition time for battery swaps, "Searching for GPS" to "ARMED".
It's about 45 seconds average for the 7N/Passive, 8 seconds for the M8N/Active setup.

With the M8N a few times if locked so quick that she was still saying the first "Searching for GPS" while Artoo was already displaying "Hold Fly to Start Motors".

Out of the antennas we had with us today, the generic Taoglas AP.25F.07.0078A worked the best, but it also had too short of a cable to allow me to mount the M8N inside.

I've order another Taoglas AP.25F.07.0078A and a AGGP.25F.07.0060A, both with longer cables for more testing. They should be here in a few days.


Some basic notes of interest from my scratchpad:
PDOP with the M8N rig hit 1.0 with 18 SATs, the 7N never got below 1.8 with 11 SATs
(on the ground, same location, both mounted external)

Then again, until I get all of the parts I ordered it's not fair to compare the M8N's Active Patch to the 7N's board mounted Passive.

More to come....

 

[Jubalr]

Nice work Steve. Always looking forward to your reports.

 

[50wyldeman]

Okay , well I have some questions here, first of all I just want to be clear , I am an absolute neophyte in the RC universe and not an Electrical engineer either, that all said I have a question in regards to the GPS issues etc that it would seem are plaguing us all .
These are thoughts and questions , I see the battery is on the top of the SOLO , as far as I can tell that is somewhat unique in the RC universe , although I don't necessarily think it would create the issue we seem to be experiencing with a non GPS device.
My first thought is this , I would believe the battery has a fair amount of lead and other metals , so unless the reciever for the GPS signal is mounted above the Battery wouldn't in some fashion at a minimum the battery act like a bit of a faraday cage blocking and or weakening the signal strength from the GPS satellites, or does it not really work that way?
Being that there is myriad of RC hardware etc out there , is there a solution that would make it possible to mount the antennas for the GPS on the SOLO side in a manner that allows a stronger signal path? would changing the antennae allow leaving the code that is in place to not be in need of a change?
Again, I am a neophyte just thinking out loud is all .
Hopefully this post is not a bother

 

[SteveMyers75]

No problem with asking questions.

The battery used in Solo is Lithium Polymer and contains no lead. (corrected from below)

I haven't cracked one open (yet) to look inside, but I'd venture a guess they are the same cells as used in a Tesla, NCR 18650 3100mAh cells.

The battery placement shouldn't be a problem.
If you look at the video of the Kamikaze Hexa in the Marco video above, the UBlox is below the exposed battery pack and doesn't seem to be an issue. (He's pointing at the UBlox 6M at 19 seconds into the video)

What is better in that video is there is nothing directly above the UBlox.
It looks like maybe some heat-shrink tubing was used to attach/protect it, but that's all.

In the other two Marco videos posted earlier in this thread, you can clearly see the GPS Antennas mounted way above everything else.

This would be ideal for the Solo, but not until they fix the "Turtle Backing" on ARMING problem.
(This only happens if you fly the Solo, Land it, pick it up and turn it upside down to do something with the GoPro then try to launch it again without turning it completely off first.)

 

[nacjr]

No problem with asking questions.

The battery used in Solo is a Lithium Ion and contains no lead.

I haven't cracked one open (yet) to look inside, but I'd venture a guess they are the same cells as used in a Tesla, NCR 18650 3100mAh cells.

That's interesting. I would have thought they were LiPo 4S batteries. How do you get 5,200mAh from 18650 cells? I guess if they were LiPo there would be a balance port unless its internal some how. Could there be like 12 18650 cells in the battery pack?

 

[SteveMyers75]

I stand corrected, they are LiPo not LiON
Had never look at the specs and was guessing what they use

 

[Earldgrayjr]

The stock GPS Module is pretty well covered in Copper RF insulation foil, but there still may be an issue here.
I've ordered up some more 2" wide 3M 1125 Copper-Adhesive backed RF shielding foil from Digikey, and I'm going to add that too.


Today's tests were short lived as the wind speed is 18-20 knots gusting to 26+.
Too much wind for me to feel at ease with the Solo in Manual mode in an emergency.
The wind is supposed to be calm tomorrow so I can do some Props-On tests with the M8N.

We did a lot of props-off testing and found that the antenna is extremely susceptible to placement underneath any of the Solo's plastic parts. (Is there lead inside this China Plastic or what??)

My Wing-man pointed out after we returned that the battery release button looks to be some other plastic than the rest of the battery case, and it has a metal spring so tomorrow we're going to do some tests without it. The internal patch antenna has to go through the Battery Case housing, the Battery Release Button and the snap-on Plastic GPS Cover.

In theory none of these should make a difference, but still I want to know why is there such lousy performance when I mount any patch there.

From the Taoglas Website:
"Close proximity to components or housing affects the electrical performance of all antennas. When placed within the enclosure, in most cases, there should be a clearance of 5mm in all directions from the housing, metal, or other components for maximum efficiency. A reduction in antenna efficiency and a shift in tuned frequency will be observed if these clearances are not maintained. Proximity effects will also have an adverse effect on the radiation pattern of the antenna. Device housings should never be metal or have metal materials when using internal antennas. Also note that some housing colorants, such as carbon black, have RF absorptive properties and can severely degrade antenna performance. Housing materials that absorb moisture, such as nylon, are also not recommended."

Reading this, and seeing that the Solo's GPS Module is mounted with the passive patch antenna pressing directly against the Battery Housing and everything inside is black plastic makes me wonder.

The M8N/Active patch still substantially outperforms the stock 7N when mounted internally, but we ended up ditching the internal mounts in favor of "Clear-Sky" exposed until I can get longer cables for the antennas.

Since I don't yet have the SMA->I-PEX adapter for my 7N module, we relocated the stock Solo 7N module external of all plastic are ran some tests.
I'll tally up a complete breakdown spreadsheet when I'm done, but I can say it didn't do much better external than internal as far as Start - Restart times.

The main issue is acquisition time for battery swaps, "Searching for GPS" to "ARMED".
It's about 45 seconds average for the 7N/Passive, 8 seconds for the M8N/Active setup.

With the M8N a few times if locked so quick that she was still saying the first "Searching for GPS" while Artoo was already displaying "Hold Fly to Start Motors".

Out of the antennas we had with us today, the generic Taoglas AP.25F.07.0078A worked the best, but it also had too short of a cable to allow me to mount the M8N inside.

I've order another Taoglas AP.25F.07.0078A and a AGGP.25F.07.0060A, both with longer cables for more testing. They should be here in a few days.


Some basic notes of interest from my scratchpad:
PDOP with the M8N rig hit 1.0 with 18 SATs, the 7N never got below 1.8 with 11 SATs
(on the ground, same location, both mounted external)

Then again, until I get all of the parts I ordered it's not fair to compare the M8N's Active Patch to the 7N's board mounted Passive.

More to come....

This is really awesome work, that I bet will make a substantive difference. Not sure where you will end up, but I would bet the outcome of this (or something 3DR is doing in parallel) will provide the real answers for what appears to be a lot of separate problems.

 

[SteveMyers75]

We did a lot of in-air testing today with Hans (my Solo) and the M8N.
Ran through 7 batteries and collected 10 fairly long flight tlogs with no issues at all.

The tests today were with both the Solo Android App and Tower Flight plans, and it all went off without a hitch.

For part of the run, I did a 3 Minute “Loiter Mode” then a 2 Minute Stationary Yaw Rotate in each direction and he was stable, with about <2 feet drift in “Z” and about 4 feet in “X-Y”.
Not as good as what Marco posted with his DJI900/NEO-M8N, but still pretty impressive.

When I have time, I’ll figure out a more exact distance by reviewing the stationary videos.
All of this will be compared to the same flight-plans using a 7N when I receive the antenna adapter I ordered.

The only thing I did notice:
We had a little sunlight left and swapped back to the stock NEO-7N under all the plastic setup.
Only then did we realize that we had been taking off and landing from a 6' x 6' piece of cardboard and pretty much RTL landing in the middle every flight with the NEO-M8N.

With the 7N, it missed the landing pad by a couple of feet on 2 of the 4 flights.

Just a thought here:
I am starting to wonder about Hans and the stock 7N module after seeing a couple of videos with people that get great GPS re-acquisition time with battery swaps.

It’s very possible that Hans has a problem with his on-board GPS Module's Battery Backed RAM (BBR) battery and he loses the cache every time I shut him down.
This would explain why it takes him so long each time...

Tomorrow I’ll check and see if the BBR battery is supplying voltage to the 7N’s V_BCKP pin or not.


Cool Video/Info Link of the Day:
http://copter.ardupilot.com/wiki/flying-arducopter/flight-modes/loiter-mode/

If you watch the video on this link, notice the location of the Takeoff and Landing... looks like within inches of each other. (You have to manually rewind the video to get to the launch)

Also if you follow the Youtube link, notice what Marco posted in the comments about the M8N....

 

[datalogger]

Ya gotta love the comment in that video 6:35 to 6:50 "It's easy to fly like me with one stick."
That makes me want to get my hands on a setup like his now!!!!

 

[SteveMyers75]

Update:

Bestbuy informed me today that the 30-Day Solo trial does not consider the release of the Gimbal because they never offered the Gimbal for sale (yet).

They made it crystal clear that it's 30-Days from the date I picked up the Solo, period. End of Discussion.

Being that so far when compared to just about anything else I fly the Solo is absolutely useless for what I wanted it for (Sports/Action Videography/Photography), and it's been 29 days since I purchased it, "Hans-Solo" was returned back to the local BestBuy store today for 100% credit back.

When they get around to actually releasing a workable Gimbal, I will re-purchase and resume my tests with the NEO-M8N as I was not impressed at all with the NEO-7N when compared.

When I do get another Solo, from what I have already seen tells me the NEO-7N/Passive is going to be the first thing I pull out of it so if anyone needs a backup stock 7N board for cheap after the 30-Days is up on my next Solo, let me know. I'll sell it for shipping costs only to anyone who shows me a need of it.

Sorry for the disappointment by returning it, but anyone that has ever flown a drone that has a 3D Gimbal will understand that this is not optional equipment for a craft such as this.
(Actually, one search of the Youtube videos comparing a DJI-P3 to a Solo should make it clear, unless you are a big fan of Jello and drinking mass quantities of Jolt Cola...)

My personal issue is with all of these 3DR Gimbal delays we have no idea if 3DR is going to pull off a working Gimbal or something with a ton of band-aids to get around some of the serious Videography issues I can think of.
The fixed landing gear on a Solo is an issue, and I need to know how the Gimbal is going to handle not filming it. The last thing anyone wants is a video of a landing gear arm panning through each video or a shot angle that is at such an angle to avoid the gear that it compromises the quality of the shot.

I don't yet know how well a Solo can capture live video when it's rotated at 45-60 degrees off horizontal plane to miss its landing gear, and how the software is going to handle this issue.

...No matter, I still don't understand why a Gimbal is is an option on a flyer as advertised like this one.
Solo was sold as an Action Videography platform, plain and simple. The Gimbal, not an extra Battery, should be "free".

If all you wanted was a Recreational Acro Flyer for doing flips/rolls/loops, I'd think there would be better options available...

 

[Ian [P13]]

If you've bought from 3DR direct, you definitely have cover 30 days after the gimbal, as it's been stated by Vu, 3DR director of support (attached).

The SoloLink communicates via Mavlink with the gimbal and it's programmed to keep the legs out of shot. This is confirmed from 3DR staff that have done video with the gimbal. In full 4K wide you can get legs in, in medium modes or using the 5.4mm lens or similar you won't. Having said that in high wind even the DJI Inspire gets props and legs in.

The videos including the one released yesterday from Malta show all the smart shots work without legs in shot.

 

[rrmccabe]

The videos including the one released yesterday from Malta show all the smart shots work without legs in shot.

I agree with you, but that video yesterday probably had 25 times the time spent on post editing as filming. So 3DRs videos have little value to me. Even if they dipped a leg into the frame you now they are going to take it out in post. Not to mention use every other possible trick in the book to make it look good.

Videos will be come important to me when @Dirby, @David Weston ,@Sarah B, etc start posting their own footage.

10 more days??

 

[Ian [P13]]

I agree with you, but that video yesterday probably had 25 times the time spent on post editing as filming. So 3DRs videos have little value to me. Even if they dipped a leg into the frame you now they are going to take it out in post.

Not true, 3DR on the gimbal blog has detailed when it has used stabilization so it doesn't attempt to hide the post process stage.

I've specifically raised this question, starting months ago with 3DR staff, the whole point of the gimbal design from its inception was avoiding the need for retracts. 4K which forces a wide mode will get the legs in shot, narrower modes will not, I'm not overjoyed that it can be a problem in 4K, but given the GoPro is better used in 2.7k as long as that's fine I'm happy (I've had it suggested 2.7k is fine, but noted all 3DR's videos to date are 1080p).

This is RAW footage unedited, it was a selfie done by a staff member at the gimbal plant a while ago, no legs:

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Here 3DR have detailed which video had post:


The one that didn't was this one, proving again, it is capable of smart shots without legs in:

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We'd need to see the above in higher winds to say where the limits are, but like I mention even your Inspire gets legs in shot in high winds and that has elevated legs!

 

[Retired2Fly]

Update:

Bestbuy informed me today that the 30-Day Solo trial does not consider the release of the Gimbal because they never offered the Gimbal for sale (yet).

They made it crystal clear that it's 30-Days from the date I picked up the Solo, period. End of Discussion.

Being that so far when compared to just about anything else I fly the Solo is absolutely useless for what I wanted it for (Sports/Action Videography/Photography), and it's been 29 days since I purchased it, "Hans-Solo" was returned back to the local BestBuy store today for 100% credit back.

When they get around to actually releasing a workable Gimbal, I will re-purchase and resume my tests with the NEO-M8N as I was not impressed at all with the NEO-7N when compared.

When I do get another Solo, from what I have already seen tells me the NEO-7N/Passive is going to be the first thing I pull out of it so if anyone needs a backup stock 7N board for cheap after the 30-Days is up on my next Solo, let me know. I'll sell it for shipping costs only to anyone who shows me a need of it.

Sorry for the disappointment by returning it, but anyone that has ever flown a drone that has a 3D Gimbal will understand that this is not optional equipment for a craft such as this.
(Actually, one search of the Youtube videos comparing a DJI-P3 to a Solo should make it clear, unless you are a big fan of Jello and drinking mass quantities of Jolt Cola...)

My personal issue is with all of these 3DR Gimbal delays we have no idea if 3DR is going to pull off a working Gimbal or something with a ton of band-aids to get around some of the serious Videography issues I can think of.
The fixed landing gear on a Solo is an issue, and I need to know how the Gimbal is going to handle not filming it. The last thing anyone wants is a video of a landing gear arm panning through each video or a shot angle that is at such an angle to avoid the gear that it compromises the quality of the shot.

I don't yet know how well a Solo can capture live video when it's rotated at 45-60 degrees off horizontal plane to miss its landing gear, and how the software is going to handle this issue.

...No matter, I still don't understand why a Gimbal is is an option on a flyer as advertised like this one.
Solo was sold as an Action Videography platform, plain and simple. The Gimbal, not an extra Battery, should be "free".

If all you wanted was a Recreational Acro Flyer for doing flips/rolls/loops, I'd think there would be better options available...

Steve you are 100% correct on the 3DR Customer Satisfaction Guarantee. Vu, nor any other official 3DR source has ever stated you get 30 days from the day the gimbal is released to initiate a return under that policy for all solo purchases purchased even if they were purchased different times subsequent to US solo's release . This is just more BS from some posted here out of context. I remembering seeing the same over at RCG before I left for vacation. The problem is some are posting responses from 3DR support with providing the original question tot hose answers. Unless you specifically ask 3DR about the30 day money back guarantee stating you purchased the solo and gimbal you are NOT going to get a valid response. The 30 Day Customer Satisfaction Guarantee ONLY has an exception for those who ORDERED SOLO AND the SOLO gimbal on the same order from an authorized retailer OR those who PREORDERD prior to 3DR's gimbal delay announcement in EARLY June. . If you meet that criteria you will indeed have 30 days to return your solo, gimbal and any accessories you purchased under the extended customer satisfaction return policy. If you purchased after solos release and subsequent gimbal delay announcement and you made multiple purchases at multiple times only the items shown on your receipt with your solo are eligible with NO extension beyond 30 days. PERIOD. Below is the standard canned email 3DR CS created for the for return request for order not placed directly through 3DR...


Hi xxx,

As we talked over the phone, I've created RMA # MBGxxxxxxxxx for you to apply for the 30 Day Money Back Guarantee on Best Buy. You may return your Solo to the place of purchase with the original receipt and the return authorization code to obtain the refund. Remember that all returns must be in like-new condition, must have all original packaging and no missing items.

Thank you for giving us a chance, we’re sorry to see you go. We’d love to have another chance in the future to serve you again. Let me know if you have any questions or if there’s anything I can do to help.

Regards,

XXXXXXX

Back on topic, in regards to the GPS hardware issue that you were addressing with solo , Before leaving for vacation I left my solo with a life-long friend of mine who works for Marshall down in Houston. He is the one who determined 3DR's GPS module implementation is flawed. He made some simple changes replacing the uBlox with one not crippled by 3DR and adding preoper shielding. He now has my solo working with GLONASS re-enabled on the stock GPS module. He is getting 17-20 satellites within 15 seconds of cold start even under the hood. I am excited and can wait to get back from vacation to pick it up. Anyway sorry to hear you are not satisfied with solo but I certainly understand your point. So far despite the bias being posted here 3DR solo rollout has been less than stellar to say the least..

 

[rrmccabe]

@Ian [P13] I never mentioned anything about stabilization. If you dont think they cut the best shots out of that video during post you are crazy !

I do not expect the legs to get in the shot. I was agreeing with you. But as I said 3DRs videos have zero value to me. Its not a good representation of raw footage. Its the best of their best.