This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

A cookie will be stored in your browser regardless of choice to prevent you being asked this question again. You will be able to change your cookie settings at any time using the link in the footer.

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
IMU deeeelaaayy
#1
So yea, I'm getting some SERIOUS delay from my IMU.

Any ideas?

Thanks

https://youtu.be/yfnn7H6M4iQ
Reply
#2
I'd suggest you first describe the status of your current setup. If it's an openplotter machine running tons of other software I would not be surprised.

No boat is expected to make that kind of sudden movements, and you must assume that any attitude measuring system filters, straightens or evens those movements out. Besides, the boat image is only a tool to give some feedback with regard to the calibration of the IMU, not the response time. What you show in your video seems particularly bad, hence my primary remark.

If you are worried about the response time, check out the scope facility that comes with pypilot; it allows real-time graphs to assess the values of internal parameters.
Reply
#3
Yea, I also had a buddy do the same test, with the same OS with the same pypilot IMU window open, his is instant. So there is definitely something wrong.

I've never in my life heard of an IMU taking 15 odd seconds to react. You can put it down to software rendering or whatever but even then, I would expect to see a 1 second delay at max.

Maybe @seandepagnier could give some input as to what he thinks? I think something very strange is going on here and with CPU and load tests, the CPU is sitting very low.
Reply
#4
(2022-01-26, 10:15 AM)deanfourie Wrote: Yea, I also had a buddy do the same test, with the same OS with the same pypilot IMU window open, his is instant. So there is definitely something wrong.

I've never in my life heard of an IMU taking 15 odd seconds to react. You can put it down to software rendering or whatever but even then, I would expect to see a 1 second delay at max.

Maybe @seandepagnier could give some input as to what he thinks? I think something very strange is going on here and with CPU and load tests, the CPU is sitting very low.

How quickly does the scope react?
Reply
#5
Otherwise may I suggest you stop the pypilot service and run boatimu at the prompt. Even Sean himself will need some diagnostics.
Reply
#6
You should try for example:
pypilot_client -c imu.pitch

rather than pypilot_calibration

Compare the delay. It is not normal. I cannot say for sure, but is there a wifi link or is this all on the same pi?

Which exact sensors and board are you using? What did your friend use?
Reply
#7
(2022-01-26, 04:42 PM)seandepagnier Wrote: You should try for example:
pypilot_client -c imu.pitch

rather than pypilot_calibration

Compare the delay.   It is not normal.   I cannot say for sure, but is there a wifi link or is this all on the same pi?  

Which exact sensors and board are you using?   What did your friend use?

Hi Sean, 

Thanks for the reply. Im using a InvenSense MPU-9150. I have tried with multiple different platforms, openplotter and also lysmarineOS. Both are producing the same results. Not sure what my friend is using, but I will link him to this thread and im sure he will chime in!

I have also tried a HMC5883L and it detects the IMU, but I get compass readings that are just stuck at the same value and do not move.

There is no wifi here, straight wired from the I2C bus and HDMI screen attached to the RaspberryPI 4. CPU load and all looks good and does not seem to be the problem. I have bought 2 new MPU-9150s and they are both behaving the same.

Im really not sure where to go from here.
Reply
#8
the 9150 is very old and the driver is not optimized or anything.

Look for 9250 or 9255. Also icm29048.
Reply
#9
try with an clean i2c bus, correct pullup resistors and add one chip after the other.

"i2cdetect -y 1" should check all adresses in sevonds.

otherwise read this stuff: http://www.netzmafia.de/skripten/hardwar...i_I2C.html

good luck - you will resolve this.

Holger
Reply
#10
(2022-01-26, 10:15 AM)deanfourie Wrote: Yea, I also had a buddy do the same test, with the same OS with the same pypilot IMU window open, his is instant. So there is definitely something wrong.

I've never in my life heard of an IMU taking 15 odd seconds to react. You can put it down to software rendering or whatever but even then, I would expect to see a 1 second delay at max.

Maybe @seandepagnier could give some input as to what he thinks? I think something very strange is going on here and with CPU and load tests, the CPU is sitting very low.

For me Waveshare 10 dof v2 works just fine. 
I think it is [color=rgba(0, 0, 0, 0.87)]module is based on MPU-9250 and BMP280[/color]

Also gives me pressure and temp via SignalK BME280/BMP280 plugin. 
Download BBN Marine OS for raspberry pi 

https://bareboat-necessities.github.io/m...at-os.html

Video of actual installation:

https://www.youtube.com/watch?v=3zMjUs2X3qU


Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)