IMU Not behaving correctly.

[rszemeti]

Hi, I've been away sailing on a different boat for a few weeks so could not respond.

I have had issues with 3 sensors now, one was the original Moitessier Hat from Open Marine, the second sensor producted similar reults to this, green ring at 90 degrees to thered ring, it was one on recommended by sailoog for the Macarthur Hat .. they gave me a supplier link on aliexpress. https://www.aliexpress.com/item/4000910277147.html

The third one is one a 9255 I have had lying about for a while, I used it with an Arduino at one point. It is the 9255 I am using now, I dont remember where I got it. The images at the very start of this thread are from the 20948

I have never, ever seen any debug output in the lower left window of the display.

I assume I have the master branch, it is whatever is shipped with the latest OpenPlotter build, with updates via apt-get.

I shall look into it again when I am on the boat in a week.

[winkaj]

Hi, I've been away sailing on a different boat for a few weeks so could not respond.

I have had issues with 3 sensors now, one was the original Moitessier Hat from Open Marine, the second sensor producted similar reults to this, green ring at 90 degrees to thered ring, it was one on recommended by sailoog for the Macarthur Hat .. they gave me a supplier link on aliexpress.  https://www.aliexpress.com/item/4000910277147.html

The third one is one a 9255 I have had lying about for a while, I used it with an Arduino at one point.  It is the 9255 I am using now, I dont remember where I got it. The images at the very start of this thread are from the 20948

I have never, ever seen any debug output in the lower left window of the display.

I assume I have the master branch, it is whatever is shipped with the latest OpenPlotter build, with updates via apt-get.

I shall look into it again when I am on the boat in a week.

Hi  , I am also having isues with  Moitesserier hat    andd the compas   ,  after reinstall  sd card  and updating .   RPI3B ,  Moitesserier hat1

[yoenn]

Hello,

I'm a newcomer in the openplotter world, trying to set it up on my raspberry. I think I am facing the same kind of problem here when I try to calibrate my IMU. (pypilot running in "Enable IMU Only mode", I only connected the IMU to the raspberry)

Observations in the calibration "accel" tab:
- red points eventually turn green, but never yellow
- no debug messages in the bottom left window
- calibration age never resets (always correspond to the pypilot service boot time), gains remain to [[0.0, 0.0, 0.0, 1.0], 1.0]

I made sure calibration lock checkbox is unchecked. This is confirmed in the pypilot client app (imu.accel.calibration.lock is False. Also, imu.accel.calibration.log is empty, I don't know if it is a relevant information)

I did not test compass calibration yet (just noticed that I see a red disc and not a red cone). I also noted that no plot shows up in the pypilot "scope" app regardless of the checkbox I click in the left panel. Maybe this is expected?

My configuration: fresh install of openplotter v3 Starting 64 bits on a Raspberry 4 B (4 Gb RAM). Pypilot version is 3.2.13-stable, all other apps are up to date. I am using a ICM 20948 I just bought.

Apart from that, the IMU seems to react properly. No warning occurs when I run a system check.

This is what I see when I run a journalctl -u pypilot_boatimu:

juil. 17 19:09:34 openplotter systemd[1]: Started pypilot boatimu.
juil. 17 19:09:35 openplotter sudo[2737]: pi : PWD=/home/pi/.pypilot ; USER=root ; COMMAND=/usr/bin/chrt -po 0 2734
juil. 17 19:09:35 openplotter sudo[2740]: pi : PWD=/home/pi/.pypilot ; USER=root ; COMMAND=/usr/bin/chrt -pf 2 2736
juil. 17 19:09:35 openplotter sudo[2740]: pam_unix(sudoession): session opened for user root(uid=0) by (uid=1000)
juil. 17 19:09:35 openplotter sudo[2737]: pam_unix(sudoession): session opened for user root(uid=0) by (uid=1000)
juil. 17 19:09:35 openplotter sudo[2740]: pam_unix(sudoession): session closed for user root
juil. 17 19:09:35 openplotter pypilot_boatimu[2736]: Settings file RTIMULib.ini loaded
juil. 17 19:09:35 openplotter pypilot_boatimu[2736]: Detected ICM20948 at option address
juil. 17 19:09:35 openplotter pypilot_boatimu[2736]: Using fusion algorithm Kalman STATE4
juil. 17 19:09:35 openplotter pypilot_boatimu[2736]: min/max compass calibration not in use
juil. 17 19:09:35 openplotter pypilot_boatimu[2736]: Using ellipsoid compass calibration
juil. 17 19:09:35 openplotter pypilot_boatimu[2736]: Using accel calibration
juil. 17 19:09:35 openplotter sudo[2737]: pam_unix(sudoession): session closed for user root
juil. 17 19:09:35 openplotter sudo[2745]: pi : PWD=/home/pi/.pypilot ; USER=root ; COMMAND=/usr/bin/chrt -pi 0 2734
juil. 17 19:09:35 openplotter sudo[2745]: pam_unix(sudoession): session opened for user root(uid=0) by (uid=1000)
juil. 17 19:09:35 openplotter sudo[2745]: pam_unix(sudoession): session closed for user root
juil. 17 19:09:35 openplotter pypilot_boatimu[2736]: ICM-20948 init complete

[rszemeti]

Can you post a picture of the exact sensor you are using?  Where did you get it?

Here are the photos.

     

   

I don't recall where I got it.

I also have this one, recommended by the MacArthur HAT guys: https://www.aliexpress.com/item/4000910277147.html  it behaves in a similar manner with transposed axes.

[yoenn]

Just FYI - I finally managed to perform the calibration successfully. I found the solution on an older thread on this forum: I had pypilot configured in "IMU Only" mode, since I did not have my arduino available yet. Changing this to "Autopilot" mode allowed me to perform the calibration as expected.

@seandepagnier, it might be useful to add some warning popup to inform users that the calibration cannot work if autopilot mode is not enabled.

Regards

[winkaj]

Just FYI - I finally managed to perform the calibration successfully. I found the solution on an older thread on this forum: I had pypilot configured in "IMU Only" mode, since I did not have my arduino available yet. Changing this to "Autopilot" mode allowed me to perform the calibration as expected.

@seandepagnier, it might be useful to add some warning popup to inform users that the calibration cannot work if autopilot mode is not enabled.

Regards

What  do i have to do , when i dont have a Autopilot  , for getting calibration ?

i find away to ignorer uart , it looks like i can calibrate .. now i need to get to my boat to swing it .

[rszemeti]

Same here, although I think my problem is different, what do I need to do just to get IMU functionality and calibration?

Is there some setting or options I can try to correct the non-aligned axes of my sensor? Can someone point me at a supplier of sensors that do actually work out of the box?

[Paskee]

Just FYI - I finally managed to perform the calibration successfully. I found the solution on an older thread on this forum: I had pypilot configured in "IMU Only" mode, since I did not have my arduino available yet. Changing this to "Autopilot" mode allowed me to perform the calibration as expected.

@seandepagnier, it might be useful to add some warning popup to inform users that the calibration cannot work if autopilot mode is not enabled.

Regards

Hello Everyone,

Thanks to Yoenn for pointing me in the right direction. I was facing the same issue as everyone here - impossible to calibrate an ICM-20948 sensor board (the sense(B) from waveshare). Whatever I did, I only obtained red and green dots on the calibration screen - never saw a yellow or blue one. There never was any message in the box below. For compass calibration, the circle made from turning the RPI along the z-axis was far from the sphere, and not overly parallel to the red plane.

From the beginning, the roll and pitch were working fine.

I have a clean install of openplotter and pypilot from the OP settings.

So i followed Yoenn advice 
> switching to autopilot mode
> discarding the warning about UART
> calibrating acceleration then compass then alignment, while locking calibration each time
> returning to IMU only mode

and that's it. Works fine now and I have the magnetic heading in OpenCPN.

ps: thanks all for your contribution to opensource sailing

[rszemeti]

So i followed Yoenn advice 
> switching to autopilot mode
> discarding the warning about UART
> calibrating acceleration then compass then alignment, while locking calibration each time
> returning to IMU only mode

I shall try this when I am back at the boat, it sounds like it is a programming error, but, so long as there is a workaround, thats fine.

[seandepagnier]

This is actually a bug. It should calibrate in imu only mode too. I thought it was already fixed though and sorry about this.

Can you check which version you have?