Mro gps

[Pedals2Paddles]

The way I read the ublox document, is that it will operate at 3hz with 3 systems selected. Not that it was recommended or something you should set. That it is what it will do. I could be wrong. But but it doesn't seem like a good idea to do the opposite of what the ArduPilot developers say acceptable. Good luck getting a straight answer out of ublox on this.

 

[cynfab]

mRo is in San Diego, so is the only u-blox engineering office in North America. Ask mRo to ask u-blox about that issue and have them forward the FAE's response, not paraphrase it. mRo tends to have their own view of how the world works.
The nav solution engine and the data output engine are most likely 2 separate threads in the onboard ARM processor, their rates are most likely independent so while you may see output rates of >5, >10 per second, they may not be unique solutions. How those solutions effect the EKF is a good subject for a Masters Thesis.

 

[Pedals2Paddles]

It's also highly unlikely that you'll see a functional, useful gain by adding a third system. Adding the 2-4 more sats when you already have 13-18 to begin with isn't going to make anything work any better in any way you will notice. But it certainly has the potential to create a problems due to the slower update rate conflicting with what ArduCopter expects to see.

Now, there is obviously plenty of merit to choosing the two systems that are best where you're located. If you're in europe or Asia, you may be better served to swap GLONASS for Galileo or Beidou.

 

[Rotorboy2.4gh]

It's also highly unlikely that you'll see a functional, useful gain by adding a third system. Adding the 2-4 more sats when you already have 13-18 to begin with isn't going to make anything work any better in any way you will notice. But it certainly has the potential to create a problems due to the slower update rate conflicting with what ArduCopter expects to see.

Now, there is obviously plenty of merit to choosing the two systems that are best where you're located. If you're in europe or Asia, you may be better served to swap GLONASS for Galileo or Beidou.

Matt, I have decided my issues are coming from my GPS being inside of solo with long acquisition time and losing GPS lock. Upon moving my mro to the top of solo, improved my acquisition time tenfold. So my question for you, and I regard your opinion highly, is after buying a external Mast kit, what is your opinion of putting the mro on the Mast and using the compass in the leg, or using the here GPS with the compass integrated into the GPS on the mast. Frank.

 

[Pedals2Paddles]

The HERE kit from Jesters will solve all that for you. Mast, GPS, and compass, all up high where they belong.

 

[Rotorboy2.4gh]

The HERE kit from Jesters will solve all that for you. Mast, GPS, and compass, all up high where they belong.

I saw that. Imp sells the same mast with identical shell for the here GPS, but also sell a shell for the Mro and you just extend your cable, But, you use the original compass in the leg. Being I already have the Mro, is there a downside to using it with the leg compass?? I have no problem buying Jesters complete kit, just picking your brain on possible downside of using the Mro on the mast with compass in the leg. Frank.

 

[Pedals2Paddles]

Since you already have the mRo GPS.... if you're willing and able to extend the wiring for the GPS, I think you'd be fine

 

[Rotorboy2.4gh]

Extending the cable is a easy task. As long as it will work as good as the here, I'm very willing. Thanks again Matt. Frank.

 

[Rotorboy2.4gh]

Since you already have the mRo GPS.... if you're willing and able to extend the wiring for the GPS, I think you'd be fine

Well, up until now I have been doing all of this for a friend's solo and being it is the first time I've encountered a solo have learned a lot from all of you guys in a short period of time. Having said that, for Christmas I just got in the mail yesterday from a sister and brother-in-law, you guessed it a solo. I will apply all of the knowledge I have learned from everyone on here especially mat to my new drone. I want to thank everyone on here for giving me a hand as well as my friend appreciates it more than you know. I'm sure I will be picking your brain more in the future and I'm sure somewhere along the line I will be able to add help to some others as well. Thank you much. Frank

 

[Rotorboy2.4gh]

So, I have upgraded the new solo with WiFi cards and instead of the Mro GPS, as I believe I just had an isolated bad unit, because I lost GPS lock on many occasions with 12 plus SATs, and sometimes took 2 min plus to get any SATs at all, decided to go with the here GPS with imp mast. Now this is what I'm accustomed to. 8-9 SATs instantly, and 17 SATs and lock in UNDER 30 SECONDS!!! BTW, THAT WAS IN MY LIVING ROOM AFTER A COMPASS CAL OUTSIDE. Another restart this morning, and same results!!!!!!! I could not be happier. No more lock loss in same area. Yipeeeee! So, I then purchased Solex and missions, and loaded 3.0-- 50 bucks-- didn't have the warm fuzzys about that, then figured, I'm sure it will be well worth it, as I will be going green Cube soon, not to mention--- Mat has helped every single person who ask, and then some. I'm not one to suck needed info from someone and just expect those who put that kind of time in for the GOOD, of all of us and just take it for granted. NOT FROM ME!!!! Looking forward to the future of solo, and we would be fools to think the old group of guys that have come together, will not eventually come up with a new continuing, or additional platform that will Excell far beyond anything out there and this time, failure---- will not be an option. Just my 2 cents!! Frank.

 

[IronRanger]

Spoke to mRo today GPS, Glosnass and Galieo are turned on by default before they ship.

 

[Rotorboy2.4gh]

Spoke to mRo today GPS, Glosnass and Galieo are turned on by default before they ship.

Through u center, mine showed USA gps--with waas augmentation--Glonass. I recommend even with mro, put on a imp mast or better yet, use the here GPS to get the compass up high as well

 

[Pedals2Paddles]

A few points after discussion the ArduPilot dev conference call today:

• UBLOX documentation states that using 3 constellations will reduce the update rate from 5hz to 3hz.
  
  
• ArduPilot requires a minimum of 5hz. And that lower 3hz rate with 3 constellations enabled is too low for ArduPilot to make use of. It will cause performance problems and crappy handling.
  
  
• In ArduCopter 3.5 or the old solo version of ArduCopter, that pre-arm check does not exist. So you will still be able to fly with that crappy 3hz update rate. But it is with the risk of crappy position performance that could adversely affect flight handling.
  
  
• In ArduCopter 3.6-dev (master), there is a pre-arm check for the update rate. If it is less than 5hz, it will throw a GPS Unhealthy pre-arm failure and it will not fly.

I've ordered one of these from mRo so I can see what configuration it is actually shipping with, and test it's performance under the above circumstances. Someone from ArduPilot will probably contact Jordi / mRo to talk to him about this after the test results are in. Whether he is actually shipping them with all 3 enabled or not right now, it is critical he understands that he should not be doing it, and should not be suggesting it as a selling point!

 

[Wetstone]

Thanks for looking into this! I'll be eagerly awaiting the results.

 

[Rotorboy2.4gh]

A few points after discussion the ArduPilot dev conference call today:

• UBLOX documentation states that using 3 constellations will reduce the update rate from 5hz to 3hz.
  
  
• ArduPilot requires a minimum of 5hz. And that lower 3hz rate with 3 constellations enabled is too low for ArduPilot to make use of. It will cause performance problems and crappy handling.
  
  
• In ArduCopter 3.5 or the old solo version of ArduCopter, that pre-arm check does not exist. So you will still be able to fly with that crappy 3hz update rate. But it is with the risk of crappy position performance that could adversely affect flight handling.
  
  
• In ArduCopter 3.6-dev (master), there is a pre-arm check for the update rate. If it is less than 5hz, it will throw a GPS Unhealthy pre-arm failure and it will not fly.

I've ordered one of these from mRo so I can see what configuration it is actually shipping with, and test it's performance under the above circumstances. Someone from ArduPilot will probably contact Jordi / mRo to talk to him about this after the test results are in. Whether he is actually shipping them with all 3 enabled or not right now, it is critical he understands that he should not be doing it, and should not be suggesting it as a selling point!

Nice job Matt. That should straighten all out. Mine, I thought from the get go was something wrong. GPS, waas augmentation, Galileo, and Glonass. After reading your previous threads you had posted about the 3 Hertz vs 5 Hertz I figured either mine had a third added to it by mistake or they're all coming like that. Being some people were having a bit better results than me I thought maybe mine was just a mistake. I'm not sure. Nevertheless it sounds like you have a jump on getting it all rectified. Great job as always. Frank.

 

[Pedals2Paddles]

Did you ever actually look at it through ucenter out of the box to see what was enabled out of the box? I'm curious if anyone has gotten one of these and looked.

 

[Peen]

Yes, it's GPS and GLONASS via Ublox. HERE is the same configuration out of the box.

 

[Pedals2Paddles]

Yes, it's GPS and GLONASS via Ublox. HERE is the same configuration out of the box.

And that's one of his new purple boards with the USB connector?

This is so frustrating because his advertising, his statements to customers, and actual product say three different things.

 

[Peen]

It's the newer one, with USB and purple. Not sure I fully understand what's going on here, but with 3 constellations enabled, according to Ublox it's still showing 5hz in CFG-Rates. I can even set it up to almost 20hz. Unless Pixhawk is down sampling/clocking it when it see's 3 enabled at once?

 

[Pedals2Paddles]

The ublox docs I read, and the several other (who know way more than me) have read state that it slows to 3hz with 3 constellations. However, it doesn't provide any more detail than that. Does it slow to 3 and report 5? Does it slow to 3 and report 3? Does it do something else not documented?

None the less, if the updates come in at less than 5hz for real (regardless of what ublox claims its update rate is), it will trigger the GPS unhealthy pre-arm failure.