First flight test with a ublox M8 GPS

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Peter Plischka

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May 17, 2014, 11:03:37 AM5/17/14
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Hi there,

attached a log file from a flight with a ublox M8 GPS and a 3DR ublox 6 GPS.

Between the houses a maximum of 13 Sats were achieved with the M8.
The ublox 6 had reached a maximum of 8 Sats.

The copter was very good in the air in hybrid mode.

The values ​​of ofsl ofsQ magl magQ look completely different than a ublox 6 

@ Paul
It was the version e924da4fec871ec5f0df4c786d9ef2d124f8e0b6  


regards Peter



2014-05-17 16-30-32 X600 ublox M8.zip
ublox M8 ofsl_ofsQ_magl_magQ .jpg
ublox 6 ofsl_ofsQ_magl_magQ.jpg

Julien Dubois

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May 18, 2014, 4:43:47 PM5/18/14
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Sounds great Peter!

From your log, the flight seems not very agressive and it would be interesting to see how the GPS module works in hard conditions
cf. Andrew's post here: http://diydrones.com/profiles/blogs/ublox-m8-series-gps-glonass-receiver-test

Still from you log, HDop was very bad at the beginning even with 8 sats.

Finally, Hybrid should be usefull to test GPS in hard condition as it's the more agressive flight mode that relies on GPS imo... so your choice for this test was the right one!

Where have you got the M8 module? Is it something like http://www.csgshop.com/product.php?id_product=170

Julien

Peter Plischka

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May 19, 2014, 2:19:00 AM5/19/14
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Hello Julien.

It is this one:
http://www.csgshop.com/product.php?id_product=171

Unfortunately, here in front of the house is not enough space for a longer flight.
I'll try later on a larger area.

With enough Sats the accuracy is very good. Yesterday it was 15 Sats and HDOP of 1.16 

regards Peter

2014-05-18 17-59-15 X600.zip

john...@gmail.com

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May 19, 2014, 6:03:07 AM5/19/14
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A high number of satellites found is usually a indication of good GPS conditions, but does not automatically translate to a low HDOP value. It is the position of the locked satellites in relation to your GPS receiver that decided how good the horizontal resolution will be (triangulation). A high satellite count means that you have a strong lock and there is less chance you will lose the GPS solution during flight. And in practice it usually results in low HDOP, but there is no guarantee.

- JAB

Cornel Fudulu

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May 19, 2014, 3:09:24 PM5/19/14
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I'm playing with an M8N myself, and I also saw more sattelites but worse HDOP around the house.
I'm waiting for a NEO-6 GPS with external LNA and SAW to swap the M8N module in, because I can't find a config option for the internal SAW filter.

Paul Riseborough

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May 19, 2014, 4:41:49 PM5/19/14
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HDOP is supposed to represent the ratio of horizontal position error to range measurement error

http://en.wikipedia.org/wiki/Dilution_of_precision_%28GPS%29

and is not an absolute accuracy (for example two receivers could have the same HDOP, but one could have better range accuracy and therefore better positional accuracy). HDOP as reported by UBlox does not appear to conform to this convention.

There isn't much value comparing HDOP values between different models of receiver. A better test would be to put two receivers side by side in a static test (with the same level of  motion filtering selected) and compare the movement in their solutions over time.

Randy Mackay

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May 19, 2014, 10:33:27 PM5/19/14
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     I wonder if it might help if MichaelO added the ability to graph the 2nd GPS’s positions in the KMZ/KML files that the mission planner produces or when you click on the “show map” in the dataflash log viewer.  I’m not totally sure if it’s necessary or if it’s only something that developers really care about and it would just add complexity and confusion for normal users.

-Randy

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Peter Plischka

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May 20, 2014, 1:46:30 AM5/20/14
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Hi Randy,

I think it's a good idea if we 
could graph information in the dataflash log viewer for both GPS Modules .

So then everyone has the opportunity two different GPS modules, or two identical modules in another location, easy to compare.
This function needs only in the advanced view available.  
 

regards Peter

Peter Plischka

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May 20, 2014, 6:52:33 AM5/20/14
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Here are two logs with the M8 and a ublox-6 module.
Once a fast flight and then a longer loiter.

With Loiter 19 Sats were obtained with a HDOP of 1.19.
In fast flight there were 18 Sats with a HDOP of 1.06

The video shows that the hexa is very good over a period of 11 min on the spot.
 
https://www.youtube.com/watch?v=bN8JwNQk_a8

Compared to the flights with the ublox-6 module I am very satisfied.


regards Peter

2014-05-20 10-29-04 X600 FSC ublox M8 dyn.Fly.zip
2014-05-20 10-40-03 X600 FSC ublox M8 Loiter.zip
2014-05-20 X600 ublox M8 dynamisch NSats.jpg
2014-05-20 X600 ublox M8 dynamisch HDop.jpg

Julien Dubois

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May 20, 2014, 7:09:12 AM5/20/14
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Very good Peter, thanks for the test!

I've never got so many Sats netheir so low HDOP with my ublox-6. That sounds very promising as I had  compared the position hold on the APM + Ublox-6 VS Naza + DJI GPS and APM was >= even with strong wind.
So, now, if GPS is again better, that will push APM on top for sure!

Can't wait to try it and see how it behaves in the worst cases


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Peter Plischka

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May 20, 2014, 7:20:10 AM5/20/14
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Julien,

I am looking forward to your test results.
 
The delivery from csgshop.com to Germany took only 4 days.
I'm going to order a few more for my other Copters.

regards Peter

Tom Coyle

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May 28, 2014, 10:17:51 AM5/28/14
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Hi Peter,

Did you have to load this new uBlox GPS with the 3DR configuration firmware to get it to communicate correctly with your APM?

Regards,
Tom C ArduRover2 Developer 

Peter Plischka

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May 28, 2014, 12:08:29 PM5/28/14
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Hi Tom,
No I have not. It is much easier to adjust the few values ​​manually.
I have:

PRT (ports) UART 1
Protocol out UBX
Baudrate 38400
RATE (Rates) Measurement Period 200 ms
Measurement Frequency 5 Hz
NAV5 (Navigation 5) Dynamic Model Airborn 4G
Fix Mode 3 - Auto 2D/3D
Min SV Elevation 10 Grad
DGPS Timeout 120 sec
SBAS Subsystem Enabled
PRN Codes EGNOS (EUROPE)
120, 124, 126, 131

 

regards Peter

Tom Coyle

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May 28, 2014, 1:03:38 PM5/28/14
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Thanks for the response Peter, much appreciated.

Regards,
Tom C ArduRover2 Developer

Peter Plischka

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May 28, 2014, 2:30:09 PM5/28/14
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No Problem Tom,

I am very happy with the M8. I get even in difficult situations (between trees and houses) more than 11 Sats. HDOP is between 100 and 200 cm.

With the ublox-6 I had only 6 Sats and was not as happy with the Loiter and Hybrid.
In an open area there are about 20 Sats.

Meanwhile, I have loaded all my copter with the M8, as the backup there is still a ublox-6 installed.

 
regards Peter

Tom Coyle

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May 28, 2014, 2:41:41 PM5/28/14
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Hi Peter,

I am presently running a two GPS configuration (#DR uBlox LEA-6s) on my Pixhawk equipped Traxxas Slash rover.

I live in southern Florida, USA and typically can get 11 to 12 sats with an HDOP as low as 1.2 when I am at my parking lot test course.

I can get up to 10 sats and a HDOP of less than 2.0 inside my house in the afternoons:-)

We are using two GPSs mainly for redundancy since one GPS will usually maintain a lock if the other one momentarily goes out of lock.

I am hoping that the M8 will get the sat count up even higher and get the HDOP close to or less than 1.0.

Regards,
Tom C ArduRover2 Developer


Peter Plischka

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May 28, 2014, 3:08:10 PM5/28/14
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Then yes you live in a good GPS area.
With the ublox-6 I've never had more than 9 Sats in the wild.
I usually fly in an area with houses and get to 5-6 Sats.

For me, the M8 is a great help.

I have ordered one with the helix antenna. and look forward to the comparison with the patch antenna.

Believed to be the helical antenna will not be as well suited for Copter or airplanes because of stronger directivity.

Could be interesting for your Rover.
 

regards Peter

Julien Dubois

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May 28, 2014, 3:26:49 PM5/28/14
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100% OK with you Peter, helix has too narrow beam for copter/plane imo.

I had ordered the M8 with patch antenna you linked me but, Lucky as I am, it's been damaged during shipping (that's what answered CSGShop to explain why I've still received nothing).
So, I wonder if they are serious seller and if I'll get the item one day...

BTW, I get up to 12-13 sats with my Neo-6m single GPS with HDOP between 1,7 - 1,9. worst cases, 7 sats.


 

regards Peter

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Peter Plischka

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May 29, 2014, 1:24:16 AM5/29/14
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Hi Julien,

but that is a shame. The shop sents unfortunately only in a plain paper envelope.

Whether they are serious, I do not know. There is no Impressum in the shop and mails are not answered.

Another shop for the M8 I have not found it yet.
 

regards Peter

Message has been deleted

Łukasz Wasik

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Jun 3, 2014, 5:29:14 AM6/3/14
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Peter how you configure that GPS? With 3DR configuration file?
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Peter Plischka

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Jun 3, 2014, 3:19:49 PM6/3/14
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Hello Lukasz, 

for the few values ​​you do not need a configuration file. 
You just have to change the following values: 

Łukasz Wasik

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Jun 3, 2014, 5:56:24 PM6/3/14
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Thanks!

Paul Riseborough

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Jun 4, 2014, 3:51:11 AM6/4/14
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With the extra satellites available with this receiver, it may be worth experimenting with a higher mask angle. There is an interesting paper which looks at the optimum mask angle and concludes that with the addition of Gallleo and GLONASS, the optimum angle is higher than it would be for just GPS.



Ben Nizette

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Jun 4, 2014, 6:05:32 AM6/4/14
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Huh, interesting. I've been doing some experiments with some
GPS/Beidou receivers and came to a similar (but far less rigorous!)
conclusion. In our case, dynamic maneuvers were putting low-elevation
satellites out of the FoV of the antenna, causing jumps in the
position solution. By increasing the software mask angle we can
simply ignore the SVs that are at highest risk of this and exclude
them from the solution entirely. Essentially we're sacrificing
accuracy for consistency but with enough sats, the trade-off seems
acceptable.

Ben.
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Peter Plischka

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Jun 4, 2014, 6:39:51 AM6/4/14
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Thank you Paul and Ben,

The difference of 5 degrees to 10 degrees in practice, be very difficult to detect.
I'm about to read the Document from Paul.

regards Peter

Andrew Tridgell

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Jun 4, 2014, 6:41:07 AM6/4/14
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Hi Paul,

> With the extra satellites available with this receiver, it may be worth
> experimenting with a higher mask angle.

makes sense, yes

We should add a GPS_ELEV_MASK parameter I think, with some reasonable
default (5 or 10 degrees maybe?). That would allow users to tune for
terrain too.

Cheers, Tridge

Julien Dubois

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Jun 4, 2014, 8:42:17 AM6/4/14
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Hi Andrew,

and what about a real time autotune? the controller adjusts this mask value to get a decent accuracy with the highest mask value possible.
In worst case, the mask is limited to 5 (no change from current perf)
In other cases, we increase consistency while keeping the same accuracy we currently have.

Julien

Peter Plischka

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Jun 4, 2014, 8:43:54 AM6/4/14
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That's fine, Andrew.
 
Due to the frequent plugging the GPS units, the DF-13 connectors are on PIXHAWK gotten loose.


regards Peter

Łukasz Wasik

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Jun 5, 2014, 2:47:39 PM6/5/14
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Someone said that Airborn mode is better for fast planes. Pedestrian mode is better for copters. Is it true?
Setting NAV, NAV2 and NAV5 to Pedestrian mode cause better accuracy for position hold.


W dniu wtorek, 3 czerwca 2014 21:19:49 UTC+2 użytkownik Peter Plischka napisał:

Peter Plischka

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Jun 5, 2014, 4:00:30 PM6/5/14
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It will be hard to see a difference.
 
You can even try out different settings and show us the difference. 

regards Peter

Łukasz Wasik

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Jun 5, 2014, 5:34:14 PM6/5/14
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OK this is the best config. Max HDOP 1.3 on the 2nd of the 4-floor building, 3m from window!
Config.txt
Message has been deleted

Ben Nizette

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Jun 5, 2014, 7:48:54 PM6/5/14
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On 6 June 2014 04:47, Łukasz Wasik <pankr...@gmail.com> wrote:
> Someone said that Airborn mode is better for fast planes. Pedestrian mode is
> better for copters. Is it true?

The defaults (used to be?) Plane used Airbourne 4G, 'Copter was
Airbourne 1 or 2G, Rover was Automotive. Tridge and I (mainly
Tridge!) did some testing 6 months ago and found that all three
probably should be using Airbourne 4G. 4G is the closest we've got to
telling the GPS not to filter at all. This is important for us
because 1) we have our own filters (INAV, recently EKF) that have more
information and can filter much more effectively than the GPS and 2)
because filtering inside the GPS introduces latency that degrades the
performance of our filters.

Things like "better accuracy for position hold" might be true if we
didn't have INAV (or if your frame vibrates heaps, in which case fix
that!), but in the general case it's best to just let INAV do its
thing.

Ben.

Peter Plischka

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Jun 5, 2014, 8:08:56 PM6/5/14
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Ah, thank you Ben,

I had not considered that.

But we can still experiment with the Min SV Elevation Mask.
I would be glad if Andrew makes it a parameter.
That would help a lot.


regards Peter

Ben Nizette

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Jun 5, 2014, 10:06:18 PM6/5/14
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Yep, for sure. It's only recently that the code's been changed to
allow parameters attached to GPS, it should be an easy-enough coding
task now.

Ben.

>>
>>
>> regards Peter

Paul Riseborough

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Jun 6, 2014, 11:24:05 PM6/6/14
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Flew the M8 today on a 3DR quad with a combination of throwing it around in hybrid mode, auto and loiter. It got 14 to 15 satellites and during the 2x15min flights experienced no glitches. Unfortunately my Pixhawk did not log the 6H plugged into the serial 4/5 port, however I have never got more than 11 satellites using a 6H and I have never done two consecutive flights without a glitch of some sort so it appears to have outperfomed the 6H in that area.

Looking at the EKF data I think the latency on the M8 data (relative to the IMU)  is different to the 220msec value set by the EKF_POS_DELAY and EKF_VEL_DELAY parameters, which were optimised for the 6H. This is causing the GPS innovations to rise during manoeuvres. I will have a look at finding a better value for EKF_POS_DELAY and EKF_VEL_DELAY using the replay facility.

I was using a 10 degree mask angle, turned SBAS off (it can cause trouble in Australia) and was using the aircraft <4g motion filter setting.

Craig Elder

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Jun 6, 2014, 11:28:28 PM6/6/14
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Thanks for the great news Paul

Did you have GPS_TYPE2 set to 1 or 2?


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Paul Riseborough

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Jun 7, 2014, 12:02:36 AM6/7/14
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I had rolled back to a previous set of params and forgot to check it. Looks like it was set to zero for those flights.

Julien Dubois

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Jun 7, 2014, 2:57:22 AM6/7/14
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Great new... still waiting for mine, this seller is definitivelly not serious.
Could you compare perfs doing the same test with different mask angle?


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Paul Riseborough

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Jun 7, 2014, 3:10:57 AM6/7/14
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Did another couple of flights with the 6H logging this time. This included some aggressive flying in hybrid mode. Observations from the logs are:

The M8 has ~100 msec less latency on the velocities than the 6H. I think I will reduce EKF_POS_DELAY and EKF_VEL_DELAY to 120 for subsequent flights.

Most importantly, the M8's velocity output never broke down under the aggressive flying, whereas the 6H did momentarily on three occasions. See attached plot showing one occurrence. Red is M8, green is 6H.


The M8 had slightly less velocity noise. 

The M8 averaged 17 and the 6H averaged 11 satellites (this is the maximum number I have seen with the 6H on this model during flight conditions)

So far, the performance of this receiver has been a noticeable improvement over the 6H in my environment (I don't get SBAS).

The wider band front end on the receiver required to cover the different satellite frequencies should theoretically make it more susceptible to RF interference, and I'm keeping it away from other equipment for the time being (its mounted out on one of the arms of the quad), so it's susceptibility to interference from the equipment typically fitted to our vehicles needs to be investigated.

Paul Riseborough

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Jun 7, 2014, 7:02:49 AM6/7/14
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BTW, the backup battery on the back of the dev board, unless it is glued down, can fatigue its mounts and you lose backup power and go back to default settings. You can see the backup battery in this image:


The battery is only supported by those thin tin leads. I had to bridge a broken track where the battery lead had lifted it and then glue the battery down to the board using CA. I would recommend a drop of CA between the backup battery and board.




Julien Dubois

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Jun 7, 2014, 7:12:38 AM6/7/14
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From  this picture I see this is the mini GPS with small antenna. So I guess we could expect even better results with bigger antenna. 35*35 for example.

gervais

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Jun 7, 2014, 7:46:07 AM6/7/14
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Am Samstag, 7. Juni 2014 13:12:38 UTC+2 schrieb Julien Dubois:

From  this picture I see this is the mini GPS with small antenna. So I guess we could expect even better results with bigger antenna. 35*35 for example.



The evaluation board with the bigger (but thinner ?) patch comes with a passive antenna, the smaller one with a different chip and active antenna. I would not bet, that the bigger one is better.
For such a small patch Peters (and others) results are amazing..even without an additional GP.

If you find a big active dual band antenna, please let us know. So far I did not.
 

Julien Dubois

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Jun 8, 2014, 3:29:38 AM6/8/14
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The patch antenna built in the test module is a RCHP 24dB active antenna.
http://www.csgshop.com/product.php?id_product=138

The bigger the surface or volume of the antenna, the best it's performances.

So, I meants for example to replace this antenna by something like that
http://www.goodluckbuy.com/32db-high-gain-cirocomm-gps-active-built-in-ceramic-patch-antenna-38386mm.html
Same RHCP active, but more surface, more volume, more gain (here, 32dB)

http://www.goodluckbuy.com/32db-high-gain-cirocomm-gps-active-built-in-ceramic-patch-antenna-38386mm.html

Julien

Loic B

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Jun 8, 2014, 7:26:52 AM6/8/14
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very interessing thread!
it could be great to have a ublox file to tune his own m8 with the best setting.

jdennings

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Jun 8, 2014, 12:20:40 PM6/8/14
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I have a couple of Neo 7m modules with separate patch antennas with about an inch of wire, that I plan to dual use (second logged for now) on arducopter  (Something like these.)  Are there any pros or cons, electrical and signal quality wise, to soldering the antennas  at the edge of the pads instead of reflow soldering them on the boards with solder fully underneath? (The boards have four large pads at each corner). Hot glue/epoxy?

Also, is there any point in jacking up the update rate now with 10Hz on the 7M and up to 18Hz on the 8M? I know the accels and gyros can take care of it all in betweek refresh rates at 5Hz, but especially at high speeds (> 40ms, say), wouldn’t more frequent updates improve accuracy and be less error-prone?

 

gervais

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Jun 8, 2014, 6:05:33 PM6/8/14
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Julien, the antennas you mentioned are single band GPS (center1575MHz) antennas and not designed for GLONASS.Bandwidth just 5MHz. Their bigger size doesn´t help.;-)

Active Dual band antennas mentioned in the u-blox hardware integration manual are heavy car types coming with an enclosure...

Craig Elder

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Jun 9, 2014, 3:14:22 AM6/9/14
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John there is no point in going faster than 5hz unless you rewrite some of the control loops.
With the current setup you will gain more performance by increasing the precision of the GPS than you will by increasing the update rate.

On Jun 8, 2014 10:39 AM, "jdennings" <john.d...@live.com> wrote:

I have a couple of Neo 7m modules with separate patch antennas with about an inch of wire, that I plan to dual use (second logged for now) on arducopter  (Something like these.)  Are there any pros or cons, electrical and signal quality wise, to soldering the antennas  at the edge of the pads instead of reflow soldering them on the boards with solder fully underneath? (The boards have four large pads at each corner). Hot glue/epoxy?

Also, is there any point in jacking up the update rate now with 10Hz on the 7M and up to 18Hz on the 8M? I know the accels and gyros can take care of it all in betweek refresh rates at 5Hz, but especially at high speeds (> 40ms, say), wouldn’t more frequent updates improve accuracy and be less error-prone?

 

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Ben Nizette

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Jun 9, 2014, 4:37:39 AM6/9/14
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.. or by reducing the latency. It might be interesting to see whether
changing the rate changes the latency (e.g. whether the unit
internally filters several successive samples if the output is not
requested at the solution rate) and if so, perform some hack along the
lines of dropping every second sample?

Ben.

Julien Dubois

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Jun 10, 2014, 7:14:41 AM6/10/14
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Gervais,

the stock antenna installed with the M8 module is centered 1575MHz with only 10MHz bandwidth... so it doesn't no fit the Glonass Range neither:  1592.9525 MHz to 1610.485 MHz. It will be just a bit closer.
So, I was hoping extra gain would compensate it and give even better results.

But, anayways, now I have received the M8, I'll order the antenna I suggested and do some comparisons.

About dual-band, you're right, that would be ideal!
Julien

gervais

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Jun 10, 2014, 4:22:23 PM6/10/14
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 Julien,

I did not receive mine yet. But I expected it to come with the CIROCOMM 605C which obviously looks different than the 1575MHz antenna of your first link.

Did you receive the antenna specs from CSG ?

CIROCOMM pages don´t reveal specs of the 605C type. 

Btw. I did experiments with a Navilock board which did not work well with a GPS patch for GLONASS. At that time I thought that this was due to GLONASS itself.  As far as I remember, Peter did as well. And according to his amazing results with the MAX-M8Q board, I just can´t believe that its equipped with a GPS single band antenna..

But if CSG told you,I have to. :-(

Dom

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Jun 10, 2014, 7:49:55 PM6/10/14
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Hi

Sorry to add this here if it's not correct, but I thought it might be interesting to those following this thread.  I started flying my f450/pixhawk quad tonight with a Navspark-GL (GPS+Glasnoss) board as the primary GPS and the 3DR GPS/Compass as the secondary.  In the evening using the 3DR external gps/compass I usually get 8-10 satellites and often have to wait an hour or so for the HDOP to get down below 2.0 (sometimes it's good straight away and I usually get 1.8-2.0, sometimes I get 2.3-2.5 and have to wait a long time).  This is all in an open field.  This evening using the Navspark I got 21 satellites and an HDOP of 0.6.  I haven't worked out if/where the second GPS is logged to so can't see to compare in mission planner.  The Navspark cost $25 and weighs 2g (apparently, it doesn't register on my digital scales!), I power it with a tiny 300mah nanotech lipo that weighs 8g and cost less than a buck but could of course power it straight from the pixhawk gps socket.  I just like the fact that I can change main batteries and be ready to fly in seconds without having to wait for a cold start.  It also has quite a reasonable sparc cpu and lots of IO pins so has some interesting possibilities - I'm currently trying to port the taranis/x8r telemetry that is running on a teensy at the moment.


navspark-apmcopter.png

Peter Plischka

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Jun 11, 2014, 1:50:11 PM6/11/14
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Hi there,

here is a quick comparison between a ublox M8N and a M8Q.
Both are mounted on a Hexa with PIXHAWK in the same amount.
GPS1 is M8N GPS2 is M8Q.

The N usually had two Sats more than Q.
    This will be due to the huge patch antenna  
.
I'm just flown between the houses.


regards Peter

2014-06-11 18-48-07 X600 GPS1 M8N GPS2 M8Q.zip
X600 GPS1 M8N GPS2 M8Q HDop.jpg
X600 GPS1 M8N GPS2 M8Q NSats.jpg

Craig Elder

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Jun 11, 2014, 2:05:18 PM6/11/14
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Peter

Have a look at the UBX1 and UBX2 messages in the dataflash log files.  Those two messages will give you the most information about the GPS.  You can find the details on how to interpret the messages in the ublox documnetation


--

Craig Elder

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Jun 11, 2014, 2:07:40 PM6/11/14
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One more thing, you need to use the current Plane or Copter beta to have access to the messages.

Plane is nice because you don't need to arm the vehicle to have those messages logged.

gervais

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Jun 11, 2014, 3:41:44 PM6/11/14
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Hi Dom,

looks great indeed. Did you use this antenna ?  http://navspark.mybigcommerce.com/internal-gps-glonass-active-antenna/

Peter Plischka

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Jun 11, 2014, 4:24:48 PM6/11/14
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Thanks for the note, Craig. I'll be looking at the documentation.

I am a member of ArduCopter Tester Group and always fly the current master commit.

The M8N is certainly a great GPS.
Maybe Andrew can even view the log file



regards Peter

Peter Plischka

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Jun 11, 2014, 4:37:01 PM6/11/14
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Craig.
 
I have today emailed with the Hannes Delago from the  ETH.
He is working on a driver rework for the PX4 Firmware . The M8 has a few other mesages.
His pull request can be found here:

https://github.com/PX4/Firmware/pull/1027

Maybe we could take over the.

At the moment ofsQ and magQ is not written in the log file.

regards Peter

gervais

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Jun 11, 2014, 5:11:45 PM6/11/14
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Thx for comparing, Peter.

Obviously better.

Did you user the compass version of the M8N or the one without ?

BR


Peter Plischka

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Jun 11, 2014, 5:59:47 PM6/11/14
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Kai, I have the version with the built-in Compass.

But I've been using the Honeywell HMC5983 on all Coptern 
with  better results than the Honeywell HMC5883L.
The M8N is has still a Honeywell HMC5883L installed.


regards Peter

Craig Elder

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Jun 11, 2014, 6:32:41 PM6/11/14