Calibration failed

[Didier B]

Hi all Openplotterists !

My config : Rpi2, V7.1beta, connected sensors : MPU9150, BMP180, HTU21, DS18B20 (2)

I couldn't calibrate properly the magnetometers of my MPU9150, Once I got more than 200 counts in each of the counters, I started the ellpsoid phase which terminated quickly, with a message :
      Failed to execute RTEIIipsoidFit.m. Only
      min/max calibration available

I remember having seen a thread on that matter, but couldn't find it ...
2 - I could register on OpenMarine, and posted same thread, which one to favour for bug reporting.

[Sailoog]

Is that the only error message you get?

Press the Reset button close to the detected IMU in the I2C sensors tab.

Open a terminal and type

Code:

cd /home/pi/.config/openplotter/imu
RTIMULibDemoGL

repeat the calibration and paste here the complete error.

[Didier B]

Is that the only error message you get?

Press the Reset button close to the detected IMU in the I2C sensors tab.

Open a terminal and type
repeat the calibration and paste here the complete error.

Code:

cd /home/pi/.config/openplotter/imu
RTIMULibDemoGL

I did the complete calibration process :

• - select IMU (default)
  
• - select fusion mode (RTQF, default)
  
• calibrate accelerometers, save min/max ;
  
• - calibrate magnetometers, save min/max, get the >200 count for each octant
  
• - launched 'process ellipsoid'
  

Here is the terminal output :

Code:

pi@openplotter:~/.config/openplotter/imu $ RTIMULibDemoGL
Settings file not found. Using defaults and creating settings file
Detected MPU9150 at option address
Using fusion algorithm RTQF
min/max compass calibration not in use
Ellipsoid compass calibration not in use
Accel calibration not in use
MPU9150 init complete
Detected BMP180
Detected HTU21D at standard address
Using fusion algorithm RTQF
min/max compass calibration not in use
Ellipsoid compass calibration not in use
Accel calibration not in use
MPU9150 init complete
Using fusion algorithm RTQF
min/max compass calibration not in use
Ellipsoid compass calibration not in use
Accel calibration not in use
MPU9150 init complete
Using fusion algorithm RTQF
min/max compass calibration not in use
Ellipsoid compass calibration not in use
Using accel calibration
MPU9150 init complete
Using fusion algorithm RTQF
Using min/max compass calibration
Ellipsoid compass calibration not in use
Using accel calibration
MPU9150 init complete
QGLContext::makeCurrent(): Cannot make invalid context current.
pi@openplotter:~/.config/openplotter/imu $

I may have missed something, as my 7" display (800x480) doesn't allow me to visualise the whole calibration window, but only its upper part...

[Sailoog]

I can not see any error in your text, the last line is normal and occurs when you close the calibrator app.

It seems that you do not complete the last step. Do you press the button "process elipsoid" when values are over 200?

Here the complete instructions for calibration:

https://github.com/sailoog/RTIMULib2/blo...ration.pdf

I can do the process successfully with a MPU-9250 sensor.

[Didier B]

Yes, I  press the button "process elipsoid" when values were over 200 ...
Unfortunately, my MPU9150 deceased for an unknown reason when I tried the Nth iteration of the calibration process.
It happened after I changed the screws from steel to brass ones. Did I applied a too strong constraint ? Or did I made a lethal short circuit ?  
The sensor is recognized in OP's I2C tab, but inspector only shows "NaN" instead of values for HDG, Pitch and Heel (while pressure, humidity and temperature sensors are properly read).
More on the matter when postman will have delivered my freshly ordered MPU9250 !

[Sailoog]

MPU9150 is dead, long life to MPU9250

Look into /home/pi/.config/openplotter/imu
there are files named RTIMULib, RTIMULib2, RTIMULib3 with information that can help to configure and to know what is happening with I2C sensors

[Didier B]

Before throwing the MPU9150 in the PCB bin, I decided to give this sensor another chance with V7.0, and, surprise, it worked !
Back again to v7.1,  values were replaced by the same "NaN" string ;
But after a reset in OP's I2C tab, when re-activated, the sensor got alive again ! Then, after a calibration process, the same error message displayed :
Failed to execute RTEIIipsoidFit.m. Only
      min/max calibration available
Eventually, after activating the sensor, same "NaN" strings were displayed in place of the values.Reset in I2C tab, and back to work !
 
This seems to demonstrate a kind of incompatibility between this MPU9150 and the Ellipsoid calibration process.

Hope I will not have the same strange behaviour with the awaited MPU9250...

Sailoog, I will read care fully the info in RTIMULibx in the meantime...

[Didier B]

re tested calibration with both types of IMU, 9150 & 9250, no success...

[Sailoog]

re tested calibration with both types of IMU, 9150 & 9250, no success...

I have no problem with 9250, so I think you should check your wiring. Calibration process involves shaking the module and if you are suffering micro interruptions in your connections that could cause errors. Once happened to me.

[Didier B]

re tested calibration with both types of IMU, 9150 & 9250, no success...

I have no problem with 9250, so I think you should check your wiring. Calibration process involves shaking the module and if you are suffering micro interruptions in your connections that could cause errors. Once happened to me.

Thanks for your support. Last test I did was with a 9150 soldered via a 5 m cable. Results are highly reproducible : all the calibration process is OK, excepted the Ellipsoid phase which fails constantly. I'd rather suspect a S/W issue : missing file or a path problem ... Did you tried this calibration process with the V0.7.1 or V0.8.0 ?