Cannot have imu calibration 2.8


Hi, this is very strange.
Everything seems to work, all the functions seems to work ( thrusters, light, laser), on telemetry I can read IMU but I cannot calibrate it, SYS and MAG are always 0.
What do I have to do?
It doesn’t work.
I downloaded again the firmware, changed the sd card too, I soldered the wires again, but no matter.
I dive the rov, it goes down, I engage DKL but the rov goes up…no way to keep it down.
This may be a software problem.
Please, tell me something


I had this problem originally and found that the vertical axis thruster was engaging in the wrong direction when depth hold was set… so other thruster would try to surface, but the imu was then trying harder. In the end, the ROV would surface with the thruster full throttle. I changed the direction on the cockpit and haven’t looked back.


Hi, so did you reverse vertical thruster?
I did it but nothing happened.
The rov comes up again.
What do you think about?
When DLK is on, the vertical thruster is locked and The rov cannot merge.
If I disengage, I can push ofcourse the rov down, then I press DLK lock
but it comes up…
My values for SYS don’t change, I cannot calibrate compass, do you think
this influence the depth lock?



Are you seeing any change in compass, pitch, roll or depth? If nothing is working, I would say there is a problem with the wiring or the IMU module itself.


Hi Jim, I bought a new Imu and mounted this on but nothing changed.
I don 't remember about pitch and roll variations, I should try again but
right now I decided to change the DB 25 connector because it may be the
main reason : opening and closing many and many times as I did, can make it
too smooth to be affordable.
Did some of you ever had the same experience?

Thanks Jim…let me know what you think about.


I have seen some strange things with bad connections. Did the DB 25 solve your problem?


Hi Jim, for the moment I am still replacing it and it took me more time than I thought. When I finish doing all I will tell you about.
Thanks for help