[12many]

Hi,

I've been trying  to get my multirotor calibrated and ready for flight, but I'm completely stumped.  I've performed the attitude calibration procedure several times, but when I switch Attitude Estimation Algorithm to GPS Navigation (INS13) I get CONFIG, ATTI, and STAB alarms.

There are quite a few posts about various aspects of GPS setup, but I can't seem to find any solid documentation of the recommended settings & procedures.  Can anyone point me to what I need to know or provide an outline of the steps I need to take?

My plan is to enable three flight modes:
1: Stabilized1 (Attititude / Attitude / AxisLock) for take off & landing
2: PositionHold  for hover
3: CourseLock for planned navigation

Hardware:
FC: Revolution
GPS: Revo GPSV9

Software:  LibrePilot 15.09

Any help would be really appreciated!

[f5soh]

You can find some info here:
https://librepilot.atlassian.net/wiki/display/LPDOC/Advanced+features

Revo GPSv9 ?

You need to remove the config alarm, please post your config file.

[TheOtherCliff]

Yea the config alarm is the first thing that must be fixed.  The others may go away after that.

One guess is that you don't have a Home Location set.  If you have telemetry or a long USB cable then set the quad on the ground where you want Home to be (wait for a good GPS lock) and in the GCS go to Configuration->Attitude->Settings and press the Clear button.  In a few seconds it will fill the coordinates in.  Press the Save button.

[12many]

Ok, to eliminate the CONFIG error I've gone back to one flight mode, not GPS related (Attitude / Attitude / AxisLock / Manual) but am leaving Attitude Estmiation Algorithm set to GPS Navigation (INS13) because I want to use the magnetometer on the GPS (explained why below).

I think now the problem is that MAG is black (off) in system health.  I've carefully followed the full calibration procedure many times.  The vehicle frame is aluminum (conductive but relatively non-magnetic material), but I have the GPS mounted on a non-metallic stalk about 20cm above the metal frame & about 40cm from other electronics & antennas.  Most of the high-current wiring (ESCs, some of the power leads) are mounted on the underside of the frame away from electronics.  The batteries (3x 6S) are mounted within 20cm of the FC, but 40cm from the GPS.  When calibrating the magnetometer I use a plastic table and work gloves to avoid interference, but I am fairly close to the house.  Could that be it?  GPS was picking up 10-11 satellites at the time of calibration.  I tried both Cliff's suggestion to set home position via GPS and setting it manually through the map.  FC is connected to GCS via OpLink telemetry.

I did extend the wires from the FC to the GPS by about 40cm, but GPS status is green and appears to be working.

In System --> Settings / AuxMagSettings Type is set to '"GPSV9" and Usage is "AuxOnly".  Is this correct?

At this point MAG is black & ATTI and STAB are red (due to MAG I assume).

Thanks for taking a look.  Ideas / suggestions always welcome.

[TheOtherCliff]

Config error means ... that. 

And it won't work enough to get to the next issue till that is fixed.

If you do indeed have a GPSv9 then I am guessing that you have it plugged in the wrong port on the GPS.  You must plug it in the port labeled MCU+GPS (or something similar).  Basically move it to the other side of the three (not in the middle).

config file looked OK

[12many]

I think (?) it's a GPS V9 aka GpsPlatinum (?).  I see references to an OP GPS V8 in some places on the web - am I confused?  I obtained my Revolution FC & GPS via the original kickstarter campaign.

However the GPS only has one port.  You're saying the V9 has more?  My GPS patch antenna is a white rectangle with "574O"  mounted to a black PCB.  The shield says  UBLOX NEO-6Q-0-001.  I can send a picture if you like.

Some specific questions:

• I noticed that the GPS has a battery spot-welded in place.  This hardware has been sitting for a long time.  It's likely the battery is dead.  Could this be the problem?
• Interesting... I just noticed that on the back of the GPS PCB in microscopic type it says 'V8 GPS'.  So I guess I have a V8 after all.  It's identified as GPSV9 in AuxMagSettings.  Could this be the problem?
• The 'Aux Mag Setup and Calibration' wiki page bullet 4 says "MainPort does not do I2C, so (on Revo and Nano) you must use FlexiPort for I2C Aux Mag.  Sparky2 can use either FlexiPort or I2CPort.".  In context this seems to mean that GPS's, not the original OP GPS. (?)  I have the GPS plugged into the Main port (Spektrum receiver is plugged into the Flexi port).  Could this be the problem?
• I seem to recall in the OP wiki days there being a page indicating GPS orientated with the connector facing forward, so that's how I mounted mine.  Could orientation be the problem?  I can't seem to find any current LP documentation on how to orient the GPS. (?)

Thanks again for all of your help (and patience!) -  I hope to be able to pay the community back in some way.

[hwh]

The V8 GPS doesn't have a mag sensor or I2C, it's just a straight uBlox GPS.  You need to turn off I2C and the settings for external mag while using it.

I've attached pictures of the back of both the V8 and V9 for future reference.

The battery could have died but the only effect that would have on a revo would be to lengthen the time it takes to get a fix.  It should recharge when the gps is powered up.  They're typically only good for a few hours, they're intended to hold settings and the satellite list between flights.

[TheOtherCliff]

Some specific questions:

• I noticed that the GPS has a battery spot-welded in place.  This hardware has been sitting for a long time.  It's likely the battery is dead.  Could this be the problem?

This is actually a supercap for exactly that reason.  They don't go bad, but they only last (almanac startup time on first flight) for about 4-5 hours.

• Interesting... I just noticed that on the back of the GPS PCB in microscopic type it says 'V8 GPS'.  So I guess I have a V8 after all.  It's identified as GPSV9 in AuxMagSettings.  Could this be the problem?

You have a V8.  It doesn't have a mag.  AuxMagSettings is where you tell it how to set it up.  You could have a V9 (with V9's mag) on Main and a second I2C auxmag on Flexi.  This tells it which mag to use.  It doesn't say "this mag was detected."  The default is V9.

• The 'Aux Mag Setup and Calibration' wiki page bullet 4 says "MainPort does not do I2C, so (on Revo and Nano) you must use FlexiPort for I2C Aux Mag.  Sparky2 can use either FlexiPort or I2CPort.".  In context this seems to mean that GPS's, not the original OP GPS. (?)  I have the GPS plugged into the Main port (Spektrum receiver is plugged into the Flexi port).  Could this be the problem?

This is talking about I2C auxmags on a separate cable.  Sparky2 can have one connected at either FlexiPort or I2CPort.  Revo and Nano can only have it on Flexi.

• I seem to recall in the OP wiki days there being a page indicating GPS orientated with the connector facing forward, so that's how I mounted mine.  Could orientation be the problem?  I can't seem to find any current LP documentation on how to orient the GPS. (?)

If the GPS has a mag then it also has an arrow and it is critical that it be pointed forward or configured differently for the different direction.[/list]

[12many]

Thanks, that's hugely helpful info.  Ordered a NEO-M8N and am planning on trying out -next.  Hard to tell but according to git history gps and especially mag are getting some big upgrades.