mRobotics M8N GPS

[Dogman1973]

I really would like to have this mRobotics GPS butmy consignment was turned back by Canadian customs (on its way to Australia) and mRobotics do not reply to there contact correspondence. Shipping was almost as much as the gps.

dose anyone know this mob personally as I would really like to get this...... also I paid for it!

Hmmm bugger... I had no trouble getting one to Melbourne. (shipped USPS)

 

[ChrisM101]

I really would like to have this mRobotics GPS butmy consignment was turned back by Canadian customs (on its way to Australia) and mRobotics do not reply to there contact correspondence. Shipping was almost as much as the gps.

dose anyone know this mob personally as I would really like to get this...... also I paid for it!

Can you just find someone in the US to put it in a half eaten jar of vegemite and send it to ya?

 

[Flying Squirrel]

I've been shipping stuff to Italy via UPS ...

 

[Flying Squirrel]

Absolutely. Doesn't it seem as if the recent rock-bottom Solo prices have unearthed some really nasty ones?

I'm still a fan of this original GPS ... I get 8 satellites with Solo sitting on the kitchen table in from of the window. 12 is the norm
with reasonable acquisition ... HDOP around 1.5 ish with occasional <1

I'm waiting on a shield and M8N so I can hang with the cool kids

 

[Marich]

I'm still a fan of this original GPS ... I get 8 satellites with Solo sitting on the kitchen table in from of the window. 12 is the norm
with reasonable acquisition ... HDOP around 1.5 ish with occasional <1

I'm waiting on a shield and M8N so I can hang with the cool kids

In my apartment building it was impossible to get more than 1 satellite with the original!
Now, believe it or not I get a lock. That's one huge difference.

 

[Stealth]

I still have the original GPS, changed only GPS Shield V2 (warranty issues).
When I got GPS lock (10+ sats, HDOP<1.0) the vertical accuracy of the GPS is awful - sometimes it shows 8-9 m. above home point when Solo is on the same point it locked sats. As to horizontal accuracy - it is what I have seen on other GPS systems 1-2 m. deviation.
Does anyone else experience such a problem?
Would appreciate any feedback from people that have changed the GPS to M8N. Gio from 3DR Tech Support said that M8N would improve greatly this inaccuracy [but will void the warranty].

 

[SPP]

Yup, and the Release 2 version elongates one of the mounting holes to account for Solo's asymmetric hole pattern. It's clearly built for the Solo, screws right in place of the stock one and uses the stock cable.

One can't help but wonder how things would be if Solo had shipped with a unit like this.

AWESOME !!! Next shopping list this will be.... thanks

 

[healthyfatboy]

I still have the original GPS, changed only GPS Shield V2 (warranty issues).
When I got GPS lock (10+ sats, HDOP<1.0) the vertical accuracy of the GPS is awful - sometimes it shows 8-9 m. above home point when Solo is on the same point it locked sats. As to horizontal accuracy - it is what I have seen on other GPS systems 1-2 m. deviation.
Does anyone else experience such a problem?
Would appreciate any feedback from people that have changed the GPS to M8N. Gio from 3DR Tech Support said that M8N would improve greatly this inaccuracy [but will void the warranty].

GPS accuracy for altitude is really not that good. The spec is up to 10m error or so. What you are seeing is technically in spec but with the baro and EKF, it shouldn't happen much. Are you seeing this issue all the time with a constant 9m error or is it only so often? Unless it's a constant issue, I doubt the M8N will help.

 

[RichWest]

The baro is built into the PH2 cube, not on the GPS module...stock or mRo version.

 

[Stealth]

GPS accuracy for altitude is really not that good. The spec is up to 10m error or so. What you are seeing is technically in spec but with the baro and EKF, it shouldn't happen much. Are you seeing this issue all the time with a constant 9m error or is it only so often? Unless it's a constant issue, I doubt the M8N will help.

Thanks for the feedback!
It is not a constant inaccuracy - sometimes it is 2-3 m., sometimes 5-6, rarely more than 8 m.
All of them under similar conditions (same location, almost no clouds).
I have flown HobbyKing Bixler 2 FPV (ArkBird autopilot) for more than a year before buying Solo. The AP (ArkBird) showed no more than 1 m. vertical inaccuracy (had more horizontal inaccuracy).
It could be dangerous when flying. The bad thing is that the inaccuracy is always positive (meaning 9 m. more above ground).
Is there any reason that the problem be in the barometer, not the GPS?
Maybe I need to do compass calibration?

 

[Stealth]

The baro is built into the PH2 cube, not on the GPS module...stock or mRo version.

Thanks! That is what I thought!
Have you personally experienced some similar issues?

 

[RichWest]

I'm fairly certain all enclosed MRs experience deviation in altitude based on how the baro see's the world. That's been my experience at least and not really a problem as I fly on flat land and very little autonomous flights.

GPS accuracy has been surprisingly good for the stock unit with mod'd or V2 shielding in a RTH event. Just my experience with my bird, ymmv.

 

[ChrisM101]

I still have the original GPS, changed only GPS Shield V2 (warranty issues).
When I got GPS lock (10+ sats, HDOP<1.0) the vertical accuracy of the GPS is awful - sometimes it shows 8-9 m. above home point when Solo is on the same point it locked sats. As to horizontal accuracy - it is what I have seen on other GPS systems 1-2 m. deviation.
Does anyone else experience such a problem?
Would appreciate any feedback from people that have changed the GPS to M8N. Gio from 3DR Tech Support said that M8N would improve greatly this inaccuracy [but will void the warranty].

The US airforce allows GPS constellation for the public down to 0.8m accuracy currently, thats typically your horizontal hold over an area. The Barometer is primary in calulating Vertical . If the variance is consistent and you have not damaged or crashed the drone, you might want to RMA and get a new drone or have them replace the PH2. Not to say its not a gps issue though, because i believe if it is misreporting somewhat then the barometric calculations can be off as well I would think.

 

[Stealth]

I'm fairly certain all enclosed MRs experience deviation in altitude based on how the baro see's the world. That's been my experience at least and not really a problem as I fly on flat land and very little autonomous flights.

GPS accuracy has been surprisingly good for the stock unit with mod'd or V2 shielding in a RTH event. Just my experience with my bird, ymmv.

Thanks for the feedback!
If convenient plz check when you land what altitude does Solo show. If possible share a picture with us.
Here is one of mine from today!

 

[Stealth]

The US airforce allows GPS constellation for the public down to 0.8m accuracy currently, thats typically your horizontal hold over an area. The Barometer is primary in calulating Vertical . If the variance is consistent and you have not damaged or crashed the drone, you might want to RMA and get a new drone or have them replace the PH2. Not to say its not a gps issue though, because i believe if it is misreporting somewhat then the barometric calculations can be off as well I would think.

Thanks, I will try and calibrate the compass first! I have not crashed Solo yet.
Before filing a claim with 3DR please advise if someone else experience such a variation in vertical accuracy!

 

[healthyfatboy]

The 0.8m accuracy for civilians is under ideal conditions and only horizontal position. Vertical positioning based on GPS is very bad so you're not going to see sub meter accuracy, maybe num even sub 5 meter accuracy. Again, like Rich said, baro can be affected by various things. If the weather changes even during a short flight, you'll see variations in pressure that can lead to errors up to what you're seeing. I looked at lots of barometers, all in the same location over a 10 minute span and while many tracked similarly, some were off by quite a bit over that short time.
Our sensors on these things are far from perfect. I bet if you log what your altitude offset is at landing for the next 10 flights, just on your own vehicle, you'll end up with a range of values that are good and bad. If they're consistently bad, then contact 3DR. If not, then it's your standard GPS and baro errors from low cost sensors.

 

[David Boulanger]

Thanks for the feedback!
It is not a constant inaccuracy - sometimes it is 2-3 m., sometimes 5-6, rarely more than 8 m.
All of them under similar conditions (same location, almost no clouds).
I have flown HobbyKing Bixler 2 FPV (ArkBird autopilot) for more than a year before buying Solo. The AP (ArkBird) showed no more than 1 m. vertical inaccuracy (had more horizontal inaccuracy).
It could be dangerous when flying. The bad thing is that the inaccuracy is always positive (meaning 9 m. more above ground).
Is there any reason that the problem be in the barometer, not the GPS?
Maybe I need to do compass calibration?

When you arm the Solo the altitude should reset to 0. Am I wrong. That's how Ardupilot works with a Pixhawk.
Regards,
David R. Boulanger

 

[Stealth]

The 0.8m accuracy for civilians is under ideal conditions and only horizontal position. Vertical positioning based on GPS is very bad so you're not going to see sub meter accuracy, maybe num even sub 5 meter accuracy. Again, like Rich said, baro can be affected by various things. If the weather changes even during a short flight, you'll see variations in pressure that can lead to errors up to what you're seeing. I looked at lots of barometers, all in the same location over a 10 minute span and while many tracked similarly, some were off by quite a bit over that short time.
Our sensors on these things are far from perfect. I bet if you log what your altitude offset is at landing for the next 10 flights, just on your own vehicle, you'll end up with a range of values that are good and bad. If they're consistently bad, then contact 3DR. If not, then it's your standard GPS and baro errors from low cost sensors.

Thanks for the feedback. I already posted some of the readings of Solo Altitude. Sometimes Solo shows 1-2 m. Altitude even before I take off.
I need some more data from other pilots, that is why I requested it, but there is none yet!
PLZ post your Solo's Altitude on Landing.

 

[Stealth]

When you arm the Solo the altitude should reset to 0. Am I wrong. That's how Ardupilot works with a Pixhawk.
Regards,
David R. Boulanger

Sure it is. Or almost (as I wrote in my last post). The main problem is the altitude readings when Solo takes off.
Just to give you all a hint what am I talking about:
Recently I made a Presentation of a sports car, making an Orbit around it. Most of the time Solo was going up and down when he was circling the vehicle. At times it almost touched the ground.

 

[Hansolo808]

I upgraded two of my GPS to mRO M8N anyone interested in buying my stock GPS - I got two of them