[hwh]

It could depend on lots of factors.. ...

No it doesn't depend on lots of factors, just one.  You decided to ignore our advice on what type of gps to buy and save a little money by buying a cheaper GPS with an I2C mag instead of the Naza type we recommend.  The Naza you change the connector, plug it in, and it works.  It also only takes up one port instead of two. The I2C ones are always a problem because the cable has to be perfect and fairly short.  To run a longer cable reliably you have to add external pull-up resistors.  That's why every time someone asks what GPS to buy we recommend the Naza or one of the clones of it.

[prnet]

It could depend on lots of factors

I understand, i2c is due to i2c problem. but I already had a ublox m8n gps to adapt which is substantially one of the most used, and not so chip at all. And nobody told me which gps to use. I just made some research on the forum and google.

At last I substantially used the procedure reported here on the wiki which reports clearly ubx settings. I didn't find any unrecomandation for ubx as was instead for nmea protocol.
https://librepilot.atlassian.net/wiki/display/LPDOC/Configure+a+GPS+for+CC3D
the wizard procedure also let me choose between some gps, where my ubex m8n+mag is included. I found no advices about any kind of possibly trouble about it.

By the way, I'm confident that the board has some other primary problem, due to something else. Infact, if i disable gps and mag from ports, and i detach wiring, the board won't arm up either in basic(complementary mode).

the internal mag remains within 5-6%, maybe max 10%, and i set the max allowance at 15.
Then when I try to arm it immediately red flash the atti and stab warnings, which causes the board to not arm.
I can see some lags in the gcs tx/rx inputs tab... and in the lower window, i can see that bps is on red area with more than 2200bps received either when the board was with clean firmware.

As a try to monitor bps, I installed Dronin Gcs+ firmware, which is similar to librepilot, and I saw that rx packets were in the green area (800-800bps) but the board is unstable and reboot every few minutes.

Then I ask myself if this misfunction on librepilot could be due to too much data sent?


p.s. I clearly tried also to shorten the wiring and twisting with an additional mass cable, but no improvements.
I never had i2c troubles before, with other cpu also, with other electronic devices, made sometimes also with very ugly soldering points.

[f5soh]

At last I substantially used the procedure reported here on the wiki which reports clearly ubx settings. I didn't find any unrecomandation for ubx as was instead for nmea protocol.
https://librepilot.atlassian.net/wiki/display/LPDOC/Configure+a+GPS+for+CC3D

This Wiki page is only needed to configure the GPS to be used with CC3D.
Revolution board do not need this setup.

Main auxMag thread : https://forum.librepilot.org/index.php?topic=1110.0
Show you others users with I2c issues, you may need to add pullups resistors.

A 2200 bytes/s is not a problem and only occurs while you look at AuxMag tab, due to faster updates.
When you go to the Input tab you can see some lag due to normal slow update settings (every 2s) because you are not running the Tx Wizard or Manual calibration.
This means a delayed display but direct response while flying of course.
Default rates are choose to allow telemetry link over radio at 57600 (not full duplex so real baudrate around 30000)

Maybe solve first the reboot / unstable issues you have with a simple config before trying to setup a I2C mag.

[TheOtherCliff]

I'm testing some DJI GPS/mag issue today and wanted a different mag for a test, so I configured DJI GPS with I2C mag on a Sparky2.  I tried several brands of GPS with I2C mags and none would run reliably on I2CPort, but they some would run reliably on FlexiPort (some wouldn't).

The mag hiccuped several times during flight, when connected to I2CPort and it glitched to full attitude mode bank angle for less than a second.  I stopped testing that way.    Several flights with no problems as long as the a particularly good mag was connected to FlexiPort.

[prnet]

Unfortunately I'm still trying to arm it withouot external gpsand mag.
Gps+ext mag will be a second step. I just want to see it working without first, but still get crazy stab and atti warnings when arming. Green all the time,  become red for just half second when arming.. then green again. So it's impossible to fly.

is there any logger or debugger that i can activate to analyze the data when i try to arm?
Either using the minimal configuration, i cannot make it works.. 

[TheOtherCliff]

For AttitudeEstimationAlgorithm I only every use Basic or GpsNavigation/INS13.  Basic only gives you non-GPS non-mag flight.  INS13 can be used for that and also for GPS/mag guided/assisted flight.

You must have all the sensors that are required working correctly (plus calibration for mags) depending on AttitudeEstimationAlgorithm.  Remember that GPS flight uses the baro too, so you must cover it with foam as documented in the wiki.  Edit: also remember that you must set HomeLocation for INS13 and mag to work.

If your goal is GPS guided or assisted flight, please use INS13, else use Basic.

You must perform at least calibrations 1-3.  Please see the Attitude -> Help page. 

Are you now using Basic, INS13, or something else?

[f5soh]

is there any logger or debugger that i can activate to analyze the data when i try to arm?

Try Complementary, basic config and do a log:
- Tools > Start logging...
- Try to arm a few times
- Tools > Stop logging

Post the log file and the config file here.

[prnet]

I dont know how, but I can finally arm now. And I learned a lot too.

But I encountered few problems... So far I first flashed the betaflight firmware, but at this point it was a challenge, and iI was intentioned to solve the trouble.
Then it was very difficult to upload back the .bin revolution librepilot firmware. I had to use the FTTDI and ST tool and short the bootloader mode on the board, which is a mission to solder.

Then I had to manually reprogram an esc with an arduino as it didn't want to work good anymore(don't ask me why).

Finally, I was able to run librepilot again. I still see atti and stab flashing for a moment when arming, but now, it arm and the atti/stab became imemdiately green.

Now another difficult part. It works good in RATE mode. Each motor spin good at the radio inputs.

Attitude will be a challenge. I set generic quad, and I need to set PID, as the quad has a CRAZY behavior in attitude mode.

Is there a configuration I can start with?
The quad is about
2kg with battery,
turnigy plush25A escs,
3A 3 cells battery,
hextronix dt750 900kv motors which can thrust about 1kg and draw up to 18A .




 

[TheOtherCliff]

Have you actually tried to fly it in Rate or Attitude? 

[prnet]

I enadled txpid module, set pid in rattitude  mode.. I'm flying  now in attitude mode.. And I just enabled aux mag. The quad flyes good with both mags enabled now.
i'm going to enable int13 and hopefully gps tomorrow.
The main challenge will be increase the flight time. Actually I can flight about 10 minutes with a 3amps battery. But I still can cut some weight here and there.. So I  wish to earn a couple of minutes more..
PID settings was pretty simple, but I'd like to improve settings and have receiver inputs a bit more responsive.
Stay tuned..