[Jayson Black]

Ah I get it now :/ Duuuhhh. I have always called the Revo Revolution too. For some reason, I, and many others think that's its name. Many other people often correct you and say "CC3D and Revo are two different things. Which they are. But to the UN-initiated, it sounds like those people are just telling you that there is a CC3D, and a Revolution. lol. But there is No such thing is a Revolution, Is there? lol. Its an OP Revolution and there's an OP CC3D, but not a Revolution. And these days we Swap out OP for LP.

[f5soh]

Chinese cloners just called "Revolution" only for business.

CC3D has only gyro + accel, acro flight controller without GPS features.
Revolution add Mag + Baro and GPS modes.

You can see how looks original boards here:
https://librepilot.atlassian.net/wiki/display/LPDOC/About+LibrePilot

[Jayson Black]

Actually I own both the CC3D and the OP/LP Revolution. I have absolutely no friggen idea what the original title, post or description etc was that caused me to start calling the the Revo a Revolution. lol. Anyway, glad its cleared up. Sighs. Lots of testing and tinkering today. Wish me luck!

[jbarchuk]

I have absolutely no friggen idea what the original title, post or description etc was that caused me to start calling the the Revo a Revolution. lol.

Because you've seen it many times. Because googling "Revolution" (with the quotes which searches for the -phrase-) returns over SEVENTY THOUSANDS hits. When, in fact, there is no such device as a 'Revolution.' It's a marketing trick to gain more hits. Some titles toss in nano and mini even if the board has nothing to do with those boards. Many chinese manufacturers follow few rules as regards truth or fact. Sometimes it's hard to slow down a glacier.

[Jayson Black]

So im finally getting my head around the terms & conventions, and slowly getting alittle bit of an understanding on how revo works. Today, By Selecting INS13indoor, I was able to clearly see I have Interference on my Mag. I wouldn't have thought it was that  bad, but clearly its enough to cause unstable flight with EKF Also a pretty huge lack of understanding on my part too didnt help. But that's alright im getting there. I'm, one of these people that while I may take a while to get there, I surely get there in the end.

So anyway, Another hurdle I now have is my OPlink radio on board the FC seems to be stuffed, so I will have to either exchange the board or Just try with USB :/ (but ill save that for another thread)

Couple of questions

Is it possible to calibrate with USB, so long as all other magnetic interference is largely eliminated? Or is it an absolute must?

One more question: I have the Ublox Neo 6M (M8M) it does indeed have an on board compass, but only has a single cable set. What can I do or what are some of my options to use that Auxiliary Mag? Do I have to cut the cable and splice out a new cable? Or do I have to solder a new cable on some tabs on the GPS Board? None of the above if I build V 16.xx of LP? Cheers, thank you so much

[Mateusz]

Is it possible to calibrate with USB, so long as all other magnetic interference is largely eliminated? Or is it an absolute must?

One more question: I have the Ublox Neo 6M (M8M) it does indeed have an on board compass, but only has a single cable set. What can I do or what are some of my options to use that Auxiliary Mag? Do I have to cut the cable and splice out a new cable? Or do I have to solder a new cable on some tabs on the GPS Board? None of the above if I build V 16.xx of LP? Cheers, thank you so much

Hi Jayson,

It is not recommended to calibrate with USB, as your laptop might be too close and you may break your USB connector on Revo, they're fragile, it's micro-usb.
You should calibrate outdoors far from magnetic interference. Best is to press 5x Save, and on the last 6th calibration step, just rotate slowly at all axis, all directions, and diagonal, to get as much samples as possible.

You should also adjust Virtual Board Rotation to rotate magnetometer in GPS unit, such that it matches magnetometer in flight controller with it's orientation and level (this is important).

On your photo you have Mag which is routed to L (SCL) and A(SDA) pins. Best is to check with multi-meter (continuity mode) if those close pads correspond to the L and A pins. Then you can safely solder there your own pair of wires, route it out from GPS unit and use JST-SH 1.0 4pin connector (pre-assembled crimped wires from ebay) to connect to flexi-io port.

Other thing is that I2C uses 400kHz fast-mode, so cross-talk if SCL and SDA is too close may occur (maybe). Best practice would be to route those wires far apart and keep them short, below 10cm. If you have longer than 10cm I2C wires, it may work, or may not, depends on capacitance and timing. There are some tricks like pull-up resistor which may help on longer wires, but I am not a hardware guy, so my advice is try first by keeping I2C wires short and far apart or twisting scl with vcc and sda with vdd, if that does not work, then google a bit.

Another option is getting Naza compatible GPS, which has magnetometer and gps over just single serial line, and uses just one port on Revo instead of two.

[Jayson Black]

thanks Mat. Thats great starting info. (re the GPS). With USB, I have been using a USB Extension cable. I think its 1.5M Extension. So I can get nearly two meters from the Lappy. But if that's still not recommended, then I may have to get my board exchanged for a new one (from HobbyKing) as I am 99.9% sure the buiilt in Op link Radio is stuffed in someway. (It may not be, I am still exploring that in another thread). I seem to be able to get some kind of a connection. but while the ground radio is definitely transmitting something, the On board Air Radio is not transmitting anything, at least not according to the OPlink settings page and the HUD on the flight page is not responding when I move the FC around. I have an external air radio, but I don't have the right cables to connect it to FC (and im not sure if I even can hook up an ext Radio to a revo that has radio built in). Exploring all these things in another thread. Hopefully will get to the bottom of it soon

Thanks again Mateus

[Mateusz]

For the OPlink

• Make sure antenna is attached before enabling OPlink, transmiters run without atenna may fry especially at high power
• Unplug your Revo from laptop, press upate&erase and plug OPlink to update it for matching firmware
• Have a look how to bind OPlink modem with Revo's oplink https://librepilot.atlassian.net/wiki/display/LPDOC/OPLink+Configuration and http://opwiki.readthedocs.org/en/latest/user_manual/oplink/binding.html

Having oplink is actually one of best features, I also had long USB but still managed to damage micro-usb connector on one Revo Don't repeat my mistake
For mag calibration, it is better not to have unnecessary cables around which are not part of the quadcopter. Best calibration results you get by pressing "Save" 5 times and on the last time rotating aircraft in all directions slowly to collect as much samples as possible in all directions, rolls, pitch, yaw, diagonals, then Save.

INS31 (EKF) is really sensitive to bad magnetometer, it can deal with low noise, but magnetometer can go crazy if there is magnetic interference. Mag is not only used for heading, but also to determine up-side down position, imagine what happens if it gets disturb. That's why it is necessary to have mag away from switching components, wires, motors.

Once you get AuxMag communication working, you should consider twisting power wires to redirect magnetic field. First picture in attachment shows the field blue circles around the power wire. Second picture, shows what happens if you twist the wires, the field gets redirected in the direction your wire is running, so it may affect your mag less. Since it's not possible to shield from magnetic field, the only way is to redirect it. Magnetic field of earth is really weak and static compared to what wires in your quad can produce

[Jayson Black]

Ahh thanks again Mat. I was very aware of not enabling Radio before antenna was on. So im pretty sure I didn't fry it. I think its a bad antenna connection, or perhaps a firmware thing. Because I seem to be able to get some kind of signal connection happening, but Data is not sent from the Air (I judging that by the TX/Rx Data Rate). I have done the upgrade and erase thing a few times too (on the ground radio) I haven't done a rescue though, so I might try that. When both revo and ground Radio are plugged in (Separately of course) GSC shows I have BL Version 6 on both. I wish I had an RF meter for 433. Actually, if they are cheap on ebay I might even get one ( I have a weather station I would like to test where I am getting best signal to help decide where to place base station). So at least I would have two uses for it. In fact I intend going long Range one day on 433 with my bixler, so It would prolly be handy there too.

Anyway I will try Upgrade and erase on ground radio again, as well as see if upgrade and erase on the FC Helps (prolly good idea to start over). If that doesnt work I will try a rescue. If that doesnt work, i may have to consider contacting hobbyking for a replacement/refund.

Thanks again Mat, you've been a great help

[Mateusz]

I forgot to say I have only experience with normal Oplink design by Open pilot. Not cost optimized "Oplink Air" invented by Chinese cloners. I assumed you were talking about real Oplink.

[Jayson Black]

yeah turns out the I cant use an oplink mini ground (from the oplink mini air/ground combo) with the built in OPlink radio on my revo. I dunno if its just my type of revo or which, but I finally got my proper OPlink ground station and I have a very nice good strong comms link. So happy as larry now.

So now I have to try sort out my mag problems. My particular Quad comes in a few variants of its frame (Its a Speedix S250 AQ) I have purchased a complete Frame set of another variant. My one has slight inward swept rear arms (its meant to make it more maneuverable) and this is determined by the angle of the arm attach points on the upper and lower deck carbon fiber frame. So the spare frame set I got comes with the perfect 'X' Shape (this should make calibration a little easier with the FC Mounted). I originally went on to look at just buying the upper and lower deck. They were like $8 each Au. Hobby king had a special on at the time where you could by the whole frame set for $14 lol, which includes, 4 X Arms, Legs, upper and lower Deck, stickers and a screws & Nuts. So I jumped at that. I prolly should have brought two.

Anyway, seeing as I will have an extra deck , I will use spacer/Stand Off's to add a third upper Deck to mount the FC on. about Two inches above the normal upper deck. I am then hoping this will put enough distance between the PDB, ESCS, and Power Cables to significantly reduce magnetic interference. I am hoping this will suffice until I can hook up my Neo 6M with ext compass via the one cable with LP V16.xx. I really don't like messing with surface mount stuff, or surface mount size stuff. I seem to end up cooking boards :/ The only other option would be to buy the right GPS/Compass with the the two cables and right plugs, or even swap out the plugs, so long as it has a cable for each GPS and compass.

What do you guys reckon of my plans there? Will the 3 story config work with internal compass? or must I, without doubt, go for an external compass? Is there a chinese copy compass/GPS with two cables and Revolution plugs available?

Any other suggestion would be most welcome. Thanks heaps

[jbarchuk]

... "Oplink Air" invented by Chinese cloners.

'Invented by cloners.' Invent... Clone... Invent... Clone... How many different ways are there to spell oxymoron. The evolution of tech and the nonexistence of intellectual proprietary knowledge as the Chinese have been driving things for the past years will go through even more changes in the future. They may drive the whole concept of invention to oblivion because the way they steal things so quickly won't make it worthwhile (read: profitable) enough to design anything new.

[Thijs80]

I also have 'drift' issues while flying with gps assist on. (GSC 15.09+R812)

After calibrating my mags found out that for some reason in the latest release the AUXMAG is not working. Data coming from the AUXMAG seems correct (checked this in the system tab, and I2C status is green), but when i turn my external compass the data in GCS does not change.
GCS will only display the onboard mag data 

[vzoli]

Hi
Im using "next" version of libre, auxmag and neo7 gps.
In pos hold mode of in velroam fly and stay in place well but in altitude mode the quad keeps going to south. No matter where point the quads nose. Ins13 mode this way bad. In complemantary+mag+gps mode i have no problems.
Any idea to use ins13?

[f5soh]

I'm not sure what do you mean but "Altitude modes" (AltitudeHold and AltitudeVario) do not prevent from position drift, it just maintain altitude.

Please post your config file. File > Export UAV settings...