We got our new Blueboat last week and assembled it following the available guides.
During the software setup, while checking motor directions we noticed that the starboard side motor would keep spinning (slow speed) after the slider was moved down and would only stop if the boat was powered down.
After the controller setup we found out that the Starboard motor will keep spinning if foward command is given for a few seconds, but it will stop if we briefly reverse it. Sometimes, even after it stopped, the motor will keep twitching and producing noise like it wants to move and a quick reverse will also stop this. When spinning, Disarming has no effect, the motor will keep going. I switched the starboard motor to the port side and it works as intended, so its probably not related to the motor.
Is it a faulty ESC? Or is it something that can be adjusted in the parametres?
We are running the latest BlueOS version and tried both 4.4.0 and the latest stable ardusub on both Qground 4.2.8 and 4.4.4. Also tried loading the Blueboat120 params in BlueOS.
Nothing changes.
Couldn’t find any similar issues in the forum.
Hi @FredO and @CA_BlueBoat -
This is a known issue, and has an easy fix! The timing of the ESC 500 can vary very slightly on each unit, this has been corrected in newer BlueBoat model Basic ESC 500s, but can crop up on older ones or on the standard Basic ESC 500.
To fix, you simply need to adjust the 0 throttle trim point - by default it is 1510, but you may need to adjust it upwards or downwards 10-20 microseconds to have the propeller stop more reliably.
@tony-white Are you sure this has been corrected with newer ESCs? We had the exact same issue with a Blueboat ordered directly from BlueRobotics in July 2025.
Also, you have to be really careful here about the Servo numbers. They seem to be different in BlueOS and in the QGroundControl parameters. As @FredO wrote, setting SERVO1_TRIM in BlueOS to 1500 did the trick for me as well. However, if you are just going through the software setup guide https://bluerobotics.com/learn/blueboat-software-setup/#installing-qgroundcontrol (as I was) and you come across this issue, you might think SERVO3 is the correct one as this would be the one in QGroundControl.
Anyway, I needed to set the SERVO3_TRIM in QGroundControl to 1500 as well, otherwise I got an “EKF Variance” message there.
There is no way that QGC could show different parameters than BlueOS - they are identical! It is true that for skid-steer vehicles, like the BlueBoat, that channel 1 & 3 are the left and right motor channels. Which channel you adjust would depend on which motor needs the trim or direction adjustment!
The timing crystal on the ESCs can still have a small variance, especially at extremes of the temperature range (hot or cold.) Sorry for the hassle!
Finally, an EKF Variance message has nothing to do with servo trim - this indicates that your compass calibration is less than ideal, or you’re near a source of electromagnetic interference….
It is still the case that the software setup guide you and I linked says “SERVO1 is the port side motor and SERVO3 is the starboard side motor”
But I needed to adjust SERVO1_TRIM to get Starboard motor to stop spinning.
Can you please clear up which SERVO# is Starboard and which is Port? I suspect the software setup guide may have an error there.
What maybe confused me a bit about where to set the values is that QGroundControl seems to take some time to update the Parameter values it displays…
If your starboard motor is connected to Servo1, you’re likely not going to have a boat that functions in any mode but Manual! You may want to use the motor test page to verify the ESC signal wires have not been connected backwards….
This page documents that ArduRover expects channel 1 to be port/left, and channel 3 to be starboard/right - no error in the documentation!
QGroundControl, and BlueOS, take a moment to load the parameter values from the autopilot process to display and allow them to be modified.