ODrive has not been prerolled

[eirik-strand]

All I get is a message that says its not been prerolled. What is prerolling? I'm using two scooter motors with hall sensors. 56v ODrive

• I tried disabling it with parameter, but it still complains...
• I have called the engage motors service (and release motors and all other services that might solve the problem)
• The /state topic says connected
• I can read the hall sensors for both my motors, however one starts at like -8000 counts
• I have tried turning the wheels before publishing on /cmd_vel
• Motor calibration does not work, it just tells me to preroll

@neomanic Thank you for the package, can you help me with this?

[bsamadi]

@eirik-strand I have the same problem. Did you find any solutions?

[whoobee]

@eirik-strand @bsamadi I have the same problem, can you please post if you have any update on this issue?

[neomanic]

Hey all, sorry about that. I haven't generalised the package to work across different uses of the odrive, that was the intention behind the . Currently it requires prerolling to pickup the encoder index pulse before it can drive.

Try editing the line at https://github.com/neomanic/odrive_ros/blob/master/src/odrive_ros/odrive_node.py#L490
to be
if self.has_preroll and not self.driver.has_prerolled():

If that works then I can make the change here.

[whoobee]

@neomanic thanks a lot for the reply
It seems that the actual motor command is inhibited by this line:

odrive_ros/src/odrive_ros/odrive_node.py

Line 374 in 65424ca

if not self.driver.has_prerolled(): #ensure_prerolled():

I added the following statement and now the motors are turning:
if self.has_preroll and not self.driver.has_prerolled(): #ensure_prerolled():
and I set the use_preroll parameter as false in the launch file.